Satellite communication methods, terminal equipment, network equipment, computer-readable storage media, and computer program products

Abstract

A satellite communication method, terminal device, network device, computer-readable storage medium, and computer program product are provided. The satellite communication method includes: determining whether a CPE device has received a topology-aware message for perceiving the user network topology from at least one other CPE device in a virtual local area network (VLAN), wherein the VLAN includes a satellite network device and multiple CPE devices, and the satellite network device includes an SMF (Supervisory Network Element) element; and, in response to determining that the CPE device has received a topology-aware message from at least one other CPE device in the VLAN, reporting loop information to the SMF element, wherein the loop information directly or indirectly indicates the existence of a loop in the VLAN, causing the SMF element to initiate virtual stacking. This disclosure effectively detects and avoids loops.

Description

Technical Field

[0001] This disclosure relates to the field of satellite communications, and specifically to a satellite communication method, terminal equipment, network equipment, computer-readable storage medium, and computer program product. Background Technology

[0002] 5G Local Area Network (5GLAN) is a local area network service built on 5G technology. It combines the coverage capabilities of 5G wide area networks with the flexible connectivity of traditional local area networks (LANs), providing users with low-latency, highly reliable, wide-coverage, and flexibly deployable local network services. 3GPP first began researching the advantages of satellite communication for 5G terrestrial mobile communication in Release 14, listing satellite access as one of the various 5G access technologies and conducting specific research and analysis on satellite network deployment schemes and application scenarios. With the continuous upgrades of 3GPP standards, the converged air-to-ground mobile communication network has gradually improved, making it technically feasible to provide global 5G-LAN services based on satellite networks. For example, an overlay virtual local area network can be built using 5G-LAN and satellite networks. However, when using virtual local area networks, attention must be paid to the loop problem encountered in real-world LAN deployment. A loop refers to a redundant link that may exist within the LAN containing the 5G LAN. For example, when a 5G LAN is networked with an existing enterprise wired LAN (such as multiple LANs connected via User Plane Function (UPF) elements), multiple data forwarding paths may be created. For instance, two UPFs may be connected to different switches on the same LAN, causing broadcast messages to loop infinitely through the network. In this case, broadcast storms can consume a large amount of bandwidth and even lead to network paralysis. Summary of the Invention

[0003] Providing a mechanism to alleviate, reduce or eliminate at least one of the above problems would be beneficial.

[0004] In a first aspect, a satellite communication method is provided, applied to a CPE device in a virtual local area network (VLAN). The method includes: determining whether the CPE device has received a topology-aware message for sensing user network topology from at least one other CPE device in the VLAN, wherein the VLAN includes a satellite network device and multiple CPE devices, the satellite network device including a satellite network element (SMF); and in response to determining that the CPE device has received a topology-aware message from at least one other CPE device in the VLAN, reporting loop information to the SMF, the loop information directly or indirectly indicating the existence of a loop in the VLAN, causing the SMF to initiate virtual stacking.

[0005] In a second aspect, a satellite communication method is provided, applied to an SMF network element in a virtual local area network (VLAN). The method includes: in response to receiving loop information from one of a plurality of CPE devices, directly or indirectly indicating the existence of a loop in the VLAN, the SMF network element initiates virtual stacking, wherein the VLAN includes a satellite network device and the plurality of CPE devices, and the satellite network device includes the SMF network element.

[0006] In a third aspect, a satellite communication method is provided, applied to a UPF network element in a Virtual Local Area Network (VLAN). The method includes: in response to receiving a virtual stacking command from an SMF network element, the UPF network element virtually stacks multiple CPE devices in a loop of the VLAN, wherein the VLAN includes satellite network equipment and the multiple CPE devices, and the satellite network equipment includes the UPF network element.

[0007] In a fourth aspect, a satellite communication method is provided, applied to an AMF network element in a virtual local area network (VLAN). The method includes: the AMF network element receiving a first session request message from a CPE device via a third port; in response to the first session request message, the AMF network element sending a request to establish a first session to a selected SMF network element, such that the SMF network element instructs the CPE device and a UPF network element to establish a first session for carrying topology-aware messages, the topology-aware messages being used to perceive the user network topology, wherein the VLAN includes satellite network equipment and multiple CPE devices, the satellite network equipment including the AMF network element, the SMF network element, and the UPF network element.

[0008] In a fifth aspect, a terminal device is provided. The terminal device includes: one or more processors; and one or more memories coupled to the one or more processors and storing instructions thereon. When the instructions are executed individually or jointly by the one or more processors, the terminal device performs the aforementioned satellite communication method.

[0009] In a sixth aspect, a network device is provided. The network device includes: one or more processors; and one or more memories coupled to the one or more processors and storing instructions thereon. When the instructions are executed individually or jointly by the one or more processors, the network device performs the aforementioned satellite communication method.

[0010] In a seventh aspect, a non-transitory computer-readable storage medium is provided that stores machine-executable instructions. When executed by one or more processors of a machine, the machine-executable instructions cause the machine to perform any of the methods described above.

[0011] In an eighth aspect, a computer program product including machine-executable instructions is provided. When executed by one or more processors of a machine, the machine-executable instructions cause the machine to perform any of the methods described above.

[0012] It should be understood that the summary section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0013] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of some embodiments thereof in the accompanying drawings, in which:

[0014] Figure 1 This is a schematic diagram of a 5G LAN Overlay network based on the LEO spaceborne core network;

[0015] Figure 2 An exemplary virtual local area network (VLAN) that can implement embodiments of the present disclosure is shown;

[0016] Figure 3 An exemplary flowchart of a satellite communication method according to an embodiment of the present disclosure is shown;

[0017] Figure 4 This is a schematic diagram of the bidirectional interaction process between a 5G LAN terminal and the network during the registration process in a satellite communication method suitable for implementing embodiments of this disclosure;

[0018] Figure 5 This is a schematic diagram of the virtual stacking process during the establishment of a 5G LAN PDU session in a satellite communication method suitable for implementing embodiments of the present disclosure;

[0019] Figure 6 An exemplary flowchart of a satellite communication method according to an embodiment of the present disclosure is shown;

[0020] Figure 7 An exemplary flowchart of a satellite communication method according to an embodiment of the present disclosure is shown;

[0021] Figure 8 An exemplary flowchart of a satellite communication method according to an embodiment of the present disclosure is shown;

[0022] Figure 9 An exemplary flowchart illustrating the virtual stacking initiated by an SMF network element in a satellite communication method according to an embodiment of this disclosure is shown.

[0023] Figure 10 An exemplary flowchart of the satellite communication method of this disclosure for selecting a target CPE device by an SMF is shown.

[0024] Figure 11 An exemplary flowchart of a satellite communication method according to an embodiment of the present disclosure is shown;

[0025] Figure 12 An exemplary flowchart of a satellite communication method according to an embodiment of the present disclosure is shown;

[0026] Figure 13 An exemplary flowchart of a satellite communication method according to an embodiment of the present disclosure is shown; and

[0027] Figure 14 This is a simplified block diagram of an apparatus suitable for implementing embodiments of the present disclosure. Detailed Implementation

[0028] The principles of this disclosure will now be described with reference to some embodiments. It should be understood that these embodiments are described for illustrative purposes only and to assist those skilled in the art in understanding and implementing this disclosure, and do not impose any limitation on the scope of this disclosure. The disclosure described herein may be implemented in ways other than those described below.

[0029] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0030] References to "an embodiment," "embodiment," "exemplary embodiment," etc., in this disclosure indicate that the described embodiments may include specific features, structures, or characteristics, but not every embodiment needs to include specific features, structures, or characteristics. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an exemplary embodiment, whether explicitly described or not, those skilled in the art will recognize that such a feature, structure, or characteristic affects its connection to other embodiments.

[0031] It should be understood that while the terms “first” and “second”, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term “and / or” as used herein includes any and all combinations of one or more of the listed terms.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. The singular forms “a,” “an,” and “the” used herein also include the plural forms unless the context clearly indicates otherwise. The terms “a group of elements” or “a collection of elements” as used herein are intended to include one or more elements. It should also be understood that the terms “comprising,” “including,” “having,” “possessing,” “including,” and / or “comprising,” when used herein, specify the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0033] As used in this application, the term "circuit" may refer to one or more of the following:

[0034] (a) Hardware circuit implementation only (e.g., implementation only in analog and / or digital circuits)

[0035] (b) A combination of hardware circuitry and software, such as (if applicable):

[0036] (i) A combination of analog and / or digital hardware circuitry with software / firmware; and

[0037] (ii) Any part of a hardware processor (including a digital signal processor), software, and memory that work together to enable a device such as a mobile phone or server to perform various functions, and

[0038] (c) Hardware circuitry and / or processors, such as microprocessors or a portion thereof, which require software (e.g., firmware) to operate, but may be absent when software is not required to operate.

[0039] The definition of "circuit" applies to all uses of the term in this application, including in any claim. As another example, as used herein, the term "circuit" also includes implementations of hardware circuitry or processors (or processors in general) or a portion thereof and their accompanying software and / or firmware. The term "circuit" also includes, for example, baseband integrated circuits or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing network devices, if applicable to a particular claim element.

[0040] As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), New Radio (NR), Non-Terrestrial Network (NTN), etc. Furthermore, communication between terminal devices and network devices in a communication network can be performed according to any suitable generation of communication protocol, including but not limited to first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G), sixth-generation (6G) communication protocols, and / or any other protocols currently known or to be developed in the future. Embodiments of this disclosure can be applied to satellite communication systems. Given the rapid development in communications, future types of communication technologies and systems will naturally exist, and this disclosure can be implemented using these technologies and systems. The scope of this disclosure should not be considered limited to the aforementioned systems.

[0041] As used in this disclosure, the term "network device" refers to a node located on a satellite or ground segment in a satellite communication network. Terminal devices access the network and receive services through this node. Depending on the terminology and techniques used, network devices can include satellite network devices and terrestrial network devices. Satellite network devices can refer to base stations (BS) or access points (APs) that serve as satellite payloads, such as Node Bs (or NBs), evolved Node Bs (eNode Bs or eNBs), NR NBs (also called gNBs), remote radio units (RRUs), radio headers (RHs), remote radio headers (RRHs), and relay nodes. Examples of relay nodes can be integrated access and backhaul (IAB) nodes. The distributed unit (DU) portion of an IAB node can perform the functions of a "network device" and therefore can operate as a network device. In the following description, the terms "network device," "BS," and "node" are used interchangeably.

[0042] Terrestrial network equipment can include 5G core network equipment. The 5G core network (5GC) is the core control and data forwarding hub of the 5G network. Based on the "Control and User Plane Separation (CUPS)" architecture, it contains multiple logical network elements responsible for key functions such as session management, user authentication, data routing, and policy control. Among them, the Access and Mobility Management Function (AMF) network element is mainly responsible for signaling coordination of user access control, mobility management, and session management. When a user equipment (UE) powers on, the AMF executes the registration process, verifies the user's identity, and establishes a security context. When a UE moves between different base stations, the AMF coordinates the handover process to ensure communication continuity and stability. The Session Management Function (SMF) network element focuses on managing user PDU (Protocol Data Unit) sessions, including session establishment, modification, and release. It also dynamically selects User Plane Functions (UPFs) based on service requirements and precisely configures their forwarding rules to ensure the QoS (Quality of Service) requirements of different services. For example, for high-definition video streaming services, the SMF will allocate higher bandwidth and lower latency guarantees. The User Plane Function (UPF), acting as a data forwarding "gateway" in the 5G core network, is responsible for packet routing and forwarding, QoS enforcement (such as traffic shaping and rate limiting), session anchoring, and traffic statistics (for billing). UPFs can be flexibly deployed in core equipment rooms as backbone nodes or at edge nodes close to the user side, significantly reducing data transmission latency and improving user experience. The Unified Data Management (UDM) device stores user subscription data, such as user numbers, package types, and service permissions, and supports dynamic data updates and synchronization, ensuring the accuracy of user identification and service permission management in the network. The Authentication Server Function (AUSF), based on the 5G-AKA (Authentication and Key Negotiation) protocol defined by 3GPP, strictly authenticates user identities and generates encryption keys to prevent unauthorized users from accessing the network and ensure communication security. The Policy and Charging Function (PCF) translates the operator's policies, such as traffic control, charging rules, and QoS policies, into specific control commands and sends them to network elements such as AMF and SMF for execution, thereby achieving the rational allocation and efficient utilization of network resources.Network Slice Selection Assistance Information (NSSF) accurately selects suitable network slice instances for users based on their subscription data, business needs, and real-time network load, such as industrial slices and vehicle-to-everything (V2X) slices, and guides user devices to connect to the corresponding core network elements to meet the differentiated network performance requirements of different business scenarios.

[0043] The term "terminal device" refers to any terminal device capable of wireless communication. As an example and not a limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), access terminal (AT), or customer premises equipment (CPE). In this context, a CPE device is an access device that connects a user to a satellite network, primarily used to convert satellite signals into network signals usable by the user, enabling functions such as broadband internet access and voice calls. CPE devices can convert wireless signals (such as 3G, 4G, 5G, 6G) or wired broadband signals into local area network (LAN) signals for other devices to connect to. User equipment (UE) can be, for example, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), laptops, tablets, wearable devices, Internet of Things (IoT) devices, machine-type communication (MTC) devices, and in-vehicle equipment for V2X (where X refers to pedestrian, vehicle, or infrastructure / network) communication, and also has the ability to communicate with the network. In the following description, the terms "terminal equipment", "communication equipment", "terminal", and "user equipment" are used interchangeably.

[0044] A Virtual Local Area Network (VLAN) is a technology that logically divides devices that are physically located within the same local area network into multiple different domains using network devices (such as switches). In the following text, a specific example of a "Virtual Local Area Network" as described in this disclosure is a 5G LAN Overlay network. However, this disclosure is not intended to limit Virtual Local Area Networks to 5G technology. Terrestrial Virtual Local Area Networks, satellite Virtual Local Area Networks, and satellite-terrestrial converged Virtual Local Area Networks formed based on 5G backward-compatible previous-generation networks and upward-compatible later-generation networks all fall within the scope of this "Virtual Local Area Network." This disclosure uses 5G networks as an example for illustration, but it is not intended to limit its application scope.

[0045] Other related terms used in this disclosure are listed below:

[0046] S-gNB (Satellite gNodeB). In satellite-terrestrial converged communication scenarios, S-gNB refers to a base station deployed on a satellite, responsible for wireless communication with user terminals. Together with ground base stations (gNBs), it forms a communication network with wider coverage, allowing user terminals to directly access satellite or terrestrial networks through S-gNB or gNB.

[0047] IMSI (International Mobile Subscriber Identity) is a core parameter used to uniquely identify users in mobile communications and is widely used in 2G, 3G, 4G and 5G networks.

[0048] The Network Repository Function (NRF) is a key component in the 5G core network (5GC) and belongs to the core network element of the Service-Based Architecture (SBA).

[0049] NEF (Network Exposure Function) is an important component of the 5G core network, located between the 5G core network and external third-party application functions.

[0050] An Application Function (AF) is a functional entity in the 5G core network, similar to an application server, and can be owned by the operator or a trusted third party. The primary role of an AF is to act as an interface between service applications and the core network, handling specific services and application-related policies.

[0051] DN (Data Network) is the external network or service provider network that a user equipment (UE) wants to access through the 5G network.

[0052] If other unlisted terms are involved, they may be interpreted according to the conventional usage in the field.

[0053] 6G further expands the geographical scope and application scenarios of 5G-LAN, enabling cross-border private network users to achieve global LAN communication. In 3GPP Release 18, a space-ground converged mobile communication network based on low Earth orbit (LEO) satellites was first proposed. This involves carrying a Satellite UPF (S-UPF) on the space satellite payload and utilizing the Inter-Satellite Laser Link (ISL) of the LEO satellites to provide high-bandwidth and high-capacity transmission guarantees for the N19 interface between S-UPFs, making it technically feasible to provide global 5G-LAN services based on the LEO constellation. When building overlay virtual LANs using 5G-LAN and satellite networks, the loop problem encountered in real LAN deployment needs to be addressed.

[0054] Figure 1 This is a schematic diagram of a 5G LAN Overlay network based on the LEO spaceborne core network. Figure 1 The S-UPF shown represents the onboard UPF network element mounted on each satellite. Communication connections between adjacent satellites are established via ISL. An Overlay virtual local area network 100 is formed between the ground user CPE equipment and the onboard UPF network element. Figure 1 The diagram illustrates two types of loops present in Virtual LAN 100. The first is a space-based S-UPF loop. In the LEO constellation configuration, adjacent satellites establish ISLs (Integrated Service Links) with each other, potentially leading to space-based loops between multiple S-UPFs. The second is a user CPE loop. To ensure stable communication, ground users typically connect multiple communication terminals (CPE devices) accessing the satellite network to existing LAN network switches, forming link backups or aggregations. In this case, 5G-LAN will close into a loop on the ground user segment. Existing LANs refer to LANs that have already been built and put into use. When LAN loops exist, the broadcast storms generated by the loops not only severely impact network transmission performance but also cause the network processing chips of S-UPFs, user terminals (CPE devices), and servers to operate at high loads for extended periods. These problems will become even more prominent when building global 5G-LAN or 6G services using LEO-based S-UPFs in the future.

[0055] To address the aforementioned loop problem, the existing solutions and their associated issues are as follows.

[0056] Chinese patent application CN114697259A, entitled "Method and Apparatus for Avoiding Loops," proposes deploying a virtual switch on a UPF (Universal Power Grid). When a user terminal initiates a 5G-LAN service, the STP (Spanning Tree Protocol) is activated on the virtual switch. A method is provided to map the STP parameters of the user's existing LAN network to the STP parameters of the UPF virtual switch, enabling STP functionality between the 5G-LAN Overlay network and the user's existing LAN network. This achieves seamless BPDU (Bridge Protocol Data Unit) packet flow, and the entire LAN performs unified calculations of Bridge Identifier (BID), Port Identifier (PID), and Path Cost (PC) to generate a unified packet forwarding tree topology, avoiding broadcast storms caused by loops. However, this loop avoidance technology based on the STP protocol requires the S-UPF to support the Spanning Tree Protocol's computational capabilities, placing high demands on the computing power of the satellite payload and the power supply capabilities of the satellite platform. S-UPF operates on the STP protocol, requiring users to pre-configure the network topology information of their existing LANs into the 5G core network. This necessitates connecting the existing LAN network management to the NEF or a separately deployed AF, placing certain demands on the user's existing network. The entry and exit of a user's CPE, or the disconnection and establishment of ISLs between certain satellites, will alter the entire VLAN topology, potentially even interrupting data forwarding within the user's existing LAN. This necessitates recalculating STP and generating a tree topology for all network nodes, globally impacting network transmission and forwarding performance. Furthermore, global STP processing may block bridges on the terrestrial portion of the VLAN while allowing access to bridges on the satellite, increasing the pressure on satellite forwarding processing.

[0057] Chinese patent application CN115278758A, entitled "Control Method and Controller for Packet Forwarding," proposes adding a network control layer to the 5G-LAN user plane to form an SD-WAN (Software-Defined Wide Area Network) architecture. The SD-WAN network controller monitors the packet forwarding status of forwarding devices on the user plane (e.g., user switches, CPEs, S-gNBs, UPFs, etc.) in real time. When some devices forward the same packet for more than a preset threshold within a preset time window, the network controller determines that a network storm caused by a loop exists and instructs the forwarding device to drop duplicate packets on certain ports. However, this loop resolution technology based on the SD-WAN network controller requires the deployment of NMF (Network Management Function) and related operation and maintenance interfaces in the core network to monitor the traffic of user plane forwarding devices in real time. It also requires some parsing of packet headers, resulting in a significant NMF computational load. The time window and traffic threshold settings for NMF monitoring need to be configured separately for different forwarding devices, leading to complex operation and maintenance and significant engineering implementation difficulties. To support NMF's monitoring and control of existing user LANs, control plane interaction between the CPE or core network and the user LAN switches is required, necessitating upgrades to user equipment. Furthermore, the network user plane forwarding performance is already impacted to some extent during the time from NMF detection to the network storm and the subsequent packet dropping by the control forwarding device.

[0058] Unlike the solutions described above, embodiments of this disclosure propose a satellite communication method for implementing virtual user plane stacking. This method virtualizes multiple user plane forwarding links serving the same virtual network (VN) into a single link (i.e., one instance) for each user, thereby avoiding... Figure 1 The two loop scenarios are shown. The embodiments of this disclosure perform state synchronization and unified scheduling between S-UPF and CPE devices, eliminating the need for intensive STP protocol processing and effectively reducing onboard processing pressure. Simultaneously, the virtual stack can fully utilize ISL loops between S-UPFs and Uu link aggregation between satellite base stations and CPEs, improving stack stability and preventing transmission interruptions due to single-point failures.

[0059] The principles and implementation of this disclosure will now be described in detail with reference to the accompanying drawings. In the following text, CPE devices, SMF network elements, UPF network elements, and AMF network elements may be abbreviated as CPE, SMF, UPF, and AMF, respectively, and the terms UPF and S-UPF may be used interchangeably unless otherwise specified.

[0060] Figure 2An exemplary virtual local area network (VLAN) 200 that can implement embodiments of the present disclosure is shown. The VLAN 200 includes satellite network equipment and multiple CPE devices. For example... Figure 2 As shown, the satellite network equipment includes SMF network element 211, UPF network element 212, AMF network element (not shown), and satellite-based base station 213. UPF network element 212 and satellite-based base station 213 are both located on the satellite, while SMF network element 211 and AMF network element can both be located on the ground segment. Multiple CPE devices 220 are... Figure 2 The devices are designated CPE1, CPE2, CPE3, etc. Each CPE device 220 can communicate with its corresponding existing LAN device. Existing LAN devices include user switches and UEs interconnected with them. For example, CPE1 is connected to user switch 1 via port P0, and user switch 1 is connected to UE11 and UE12 via ports P1 and P2, respectively. In some embodiments, multiple CPE devices belong to the same virtual network group. Within the same virtual network group, user switches corresponding to different CPE devices 220 can also be interconnected via ports Px, for example, user switch 1 and user switch 2 are interconnected via ports Px.

[0061] It should be noted that Figure 2 The virtual LAN 200 includes three different scenarios.

[0062] Scenario 1: Multiple CPE devices belonging to the same virtual network group connect to the same satellite-based base station 213. Figure 2 In the example, User switch1 and User switch2 are deployed in the existing user LAN, connecting devices UE11, UE12, ..., UE1n respectively. User switch1 and User switch2 are connected to ports 00:00:00:00:00:02 and 00:00:00:00:00:03 of UE12, respectively. Multiple switches are connected via Px ports for bypass, enabling switch stacking. For switches in stacking mode, setting them to stacking mode allows multiple physical switches to share an address table, presenting themselves as a single virtual switch. User switch1 and User switch2 connect to the 5G-LAN Overlay network via CPE1 (SIM card number IMSI_1) and CPE2 (SIM card number IMSI_2), respectively, and both CPE1 and CPE2 are connected to the same satellite base station S-gNB1. Figure 2This explanation uses two CPE devices, CPE1 and CPE2, as an example and does not limit the number of CPE devices. In some scenarios, the number of CPE devices can be greater.

[0063] Scenario 2: Multiple CPE devices belonging to the same virtual network group connect to satellite-based base stations 213 on different satellites. For example... Figure 2 As shown, similar to Scenario 1, User switch 3 and User switch 4 in the existing user LAN operate in stacked mode. However, CPE3 and CPE4, which are respectively connected to User switch 3 and User switch 4, are connected to different satellite base stations S-gNB1 and S-gNB2 due to geographical and other reasons.

[0064] Scenario 3: Three or more CPE devices belonging to the same virtual network group are connected to different satellite base stations 213, and the ISLs between these satellite base stations 213 are connected end-to-end to form a loop. Figure 2 In the example, User switch 1 through User switch 4 in the existing user LAN are connected to CPE1, CPE2, CPE3, and CPE4, respectively. Of these four CPE devices, CPE1-CPE3 are connected to the satellite-borne base station S-gNB1 of one satellite, and CPE4 is connected to the satellite-borne base station S-gNB2 of another satellite. There can also be more satellites and corresponding satellite-borne base stations (not shown in the diagram), with the ISLs (In-Service Links) between these S-gNBs forming a loop.

[0065] It should be noted that, in Figure 2 The virtual local area network 200 shown includes the three scenarios described above. In other embodiments, the virtual local area network 200 may include only scenario one, or only scenario two, or only scenario three, or any combination of scenario one, scenario two, and scenario three, etc.

[0066] In some embodiments, the satellite may include low Earth orbit (LEO), medium Earth orbit (MEO), and geostationary orbit (GEO) satellites, etc.

[0067] The following description focuses on the first scenario to illustrate the embodiments of this disclosure, and uses a virtual local area network formed by CPE1, CPE2, S-gNB1 and S-UPF1 as an example for specific explanation.

[0068] Figure 3 An exemplary flowchart of a satellite communication method 300 according to an embodiment of the present disclosure is shown, the method 300 being applied to a CPE device 220 in a virtual local area network 200. Reference Figure 3 As shown, the satellite communication method 300 of this embodiment includes:

[0069] Step S310: Determine whether the CPE device has received a topology-aware message for perceiving the user network topology from at least one other CPE device in the virtual LAN 200, wherein the virtual LAN 200 includes satellite network equipment and multiple CPE devices, and the satellite network equipment includes SMF network element 211;

[0070] Step S320: In response to determining that the CPE device has received a topology-aware message from at least one other CPE device in the virtual LAN, the loop information is reported to the SMF network element. The loop information directly or indirectly indicates that a loop exists in the virtual LAN, causing the SMF network element to initiate virtual stacking.

[0071] It should be noted that the CPE device to be determined in step S310 can be any CPE device in the virtual local area network. The satellite communication method 300 can be applied to any CPE device in the virtual local area network.

[0072] Satellite communication method 300 uses topology-aware messages to sense the user network topology. If a CPE device receives a topology-aware message from any other CPE device in the virtual local area network 200, indicating the existence of a loop, it reports the loop information to the SMF network element 211, thereby causing the SMF network element 211 to initiate virtual stacking to break the loop.

[0073] It should be noted that the term "virtual stacking" has a common meaning in this field, referring to the logical combination of multiple physical devices or network elements into a virtual entity to achieve resource integration, performance improvement, high availability, etc., commonly seen in scenarios such as server clusters and network device stacking. Virtual stacking initiated by SMF network element 211 refers to a virtual resource integration or logical combination operation triggered or participated in by SMF network element 211. For example, in the context of 5G core network cloud deployment, SMF can initiate virtual stacking of multiple related UPF (User Plane Function) network elements according to service needs or network status, logically treating these UPFs as a whole for management and scheduling to optimize user plane data transmission performance, or virtually stacking multiple SMF instances to achieve load balancing and high availability. In the embodiments of this disclosure, the satellite network equipment also includes UPF network elements. Virtual stacking initiated by SMF network element 211 refers to the virtual stacking of UPF network element forwarding functions, thereby virtualizing multiple user plane forwarding links into a single link (i.e., one instance) for the user, thus avoiding... Figure 1 The two loop scenarios are shown.

[0074] The following description is in conjunction with the accompanying drawings. Figure 2The process shown in Scenario 1 illustrates the local switching of 5G LAN services between CPE1 and CPE2 using the local switching function of S-UPF1.

[0075] In some embodiments, the satellite network equipment further includes onboard base stations and AMF network elements. (Reference) Figure 3 As shown, before determining in step S310 whether the CPE device has received a topology-aware message from at least one other CPE device in the virtual LAN, the method further includes:

[0076] Step S301: The CPE device sends a registration message to the AMF network element through the satellite base station. The registration message includes a first tag, which is used to indicate that the CPE device supports the target service.

[0077] Step S302: The CPE device receives a feedback message from the AMF network element. The feedback message includes a second tag, which is used to indicate that the satellite supports the target service, enabling the CPE device and the satellite to establish a virtual local area network.

[0078] Through steps S301 and S302, the CPE device and network device can discover each other's ability to support the target service, thereby establishing a connection and forming a virtual local area network. In some embodiments, the target service includes 5G LAN services.

[0079] In some embodiments, the registration message includes a first extended field, which includes a first tag. The first extended field belongs to the 5GMM capability information element, UE's usagesetting information element, or UECapabilityInformation information element in the RegistrationRequest message.

[0080] In some embodiments, the feedback message includes a second extended field, which includes a second tag. The second extended field belongs to the 5GS network feature support information element in the Registration Accept message.

[0081] Figure 4 This is a schematic diagram of a bidirectional interaction process 400 between a 5G LAN terminal and a network terminal during the registration process, suitable for implementing embodiments of this disclosure. The terminal and network terminal are separated by dashed lines. The terminal refers to... Figure 2 The CPE device in the network includes Figure 2 S-gNB, SMF and S-UPF in, and Figure 2 AMF not shown in the image. Figure 4 S-gNB in ​​the text can be Figure 2S-gNB1 and S-UPF in the text can be... Figure 2 S-UPF1 in [the text]. It should be noted that... Figure 4 Using CPE1 and CPE2 as examples, this flowchart can also be used to explain the bidirectional interaction process between other CPEs in the same scenario and the network. (Reference) Figure 4 As shown, after CPE1 and CPE2 are powered on, they send a random access request message to the S-gNB in ​​step S401 to register and camp on the network. Here, we take CPE1 as an example. The random access request message includes Msg1~Msg4 sent by CPE1 through the Physical Random Access Channel (RACH). During this process, in step S402, CPE1 notifies the network that its terminal capability supports 5G-LAN through the 5GMM capability information element or UE's usage setting information element in the RegistrationRequest message. The RegistrationRequest message is the registration message. The first extended field is either the 5GMM capability information element or the UE's usage setting information element. The first tag is "5G-LAN supported". This first tag distinguishes between special subscribers with target service needs and ordinary users without such needs. After receiving the request message, in step S410, the S-gNB notifies the terminal in the RRCConnectionReconfiguration message through the 5GS networkfeature support information element in the Registration Accept message that the network also has 5G-LAN service capabilities. The RegistrationAccept message is the feedback message. The second extended field is the 5GS network feature support information element. The second tag is 5G-LAN supported.

[0082] In another embodiment, such as Figure 4As shown, in step S405, the AMF indicates that the network has 5G-LAN service capability in the 5GS network feature support information element of the Registration Accept message carried in the InitialContextSetupRequest message, that is, it carries the label 5G-LAN supported in this message. After receiving this message, the S-gNB initiates a UECapabilityEnquiry message to CPE1 in step S406. In step S407, CPE1 indicates that it enables the 5G-LAN function in the UECapabilityInformation response message. After receiving it, the S-gNB forwards the UECapabilityInformation to the AMF in step S408, and in step S410, it notifies CPE1 that the network also has 5G-LAN service capability in the RRCConnectionReconfiguration message through the 5GS networkfeature support information element in the Registration Accept message.

[0083] In some embodiments, CPE1 sends the RequestedNSSAI parameter to the network via a RegistrationRequest message. This parameter includes the NSSAI corresponding to various services supported by the CPE, including regular services and 5G-LAN services. This step can be specifically implemented in steps S402 and S403. The network sends the AllowedNSSAI parameter to the terminal via a RegistrationAccept message. This parameter includes the slice identifier NSSAI corresponding to the 5G-LAN services allowed by the current network, as queried based on the user's IMSI. This step can be specifically implemented in steps S405 and S410. When the network identifies that IMSI_1 and IMSI_2 belong to the same VN group, it sends the NSSAI corresponding to that VN to CPE1 and CPE2.

[0084] It should be noted that Figure 4 The document also shows some other steps.

[0085] In step S401, CPE1 sends a random access request message to S-gNB, and CPE1 and the network end perform network registration and residency.

[0086] In step S402, CPE1 sends Msg5:RRCSetupComplete to S-gNB, which includes a RegistrationRequest message, including a first label indicating that CPE1 has 5G LAN capability: 5G-LANsupported.

[0087] In step S403, the S-gNB sends an InitialUE message to the AMF, which includes a RegistrationRequest message and its first tag.

[0088] Step S404: NAS (Non-Access Stratum) security context establishment and authentication. Typically, after successful authentication, a security context relationship is established to create encryption and integrity protection mechanisms for NAS layer signaling and data transmission.

[0089] In step S405, the AMF sends an InitialContextSetupRequest to the S-gNB, which includes a RegistrationAccept message and a 5G-LAN supported label.

[0090] In step S406, S-gNB sends a UECapabilityEnquiry query message to CPE1.

[0091] In step S407, CPE1 sends a UECapabilityInformation message to S-gNB, which includes the first label 5G-LAN supported.

[0092] In step S408, the S-gNB sends a UECapabilityInformation message to the AMF.

[0093] Step S409, AS (Access Stratum) security is established.

[0094] In step S410, the S-gNB sends an RRCConnectionReconfiguration message to CPE1, which includes a RegistrationRequest message and a second label indicating that the S-gNB has 5G LAN capability and is supported.

[0095] In step S411, CPE1 sends an RRCConnectionReconfigurationComplete message to S-gNB, which includes a RegistrationComplete field to indicate that registration is complete.

[0096] In step S412, S-gNB sends an InitialContextSetupResponse message to AMF to confirm the establishment of the initial context.

[0097] Step S413, PDU session established.

[0098] Steps S406, S407, and S408, indicated by dashed lines in steps S401-S413 above, are optional. Other steps can also be modified or their order changed depending on the specific application scenario. Figure 4 As shown in the process, CPE1 and CPE2 can respectively complete the following two interactions with the network end:

[0099] (1) Two-way confirmation of the basic functions of 5G-LAN and the enhanced capabilities proposed in this disclosure; (2) Two-way confirmation of NSSAI corresponding to the 5G-LAN services that can be carried out by the terminal and the network under the current environment. When needed, the terminal can request to establish a 5G-LAN PDU session.

[0100] After registration is completed on CPE1, CPE2 and the network, loop detection can be performed in subsequent steps.

[0101] In some embodiments, each CPE device includes an air-to-ground port for communicating with a corresponding satellite-based base station and a wide area network (WAN) interface for communicating with a corresponding switch. In some embodiments, the air-to-ground port is a Uu port, and the WAN interface is a WAN port. (See reference) Figure 2 As shown, taking CPE1 as an example, CPE1 communicates with the corresponding satellite base station S-gNB1 through the Uu port and communicates with the corresponding switch User switch1 through the WAN port.

[0102] After the PUD session is established in step S413, each CPE device sends a first session request message to the AMF network element through its air port, causing the AMF network element to initiate the establishment of a first session between each CPE device and the UPF network element to carry topology-aware packets. Each CPE device sends its own topology-aware packets to the corresponding switch through its WAN interface. The switch corresponding to each CPE device is set to stacking mode, so that the switch corresponding to each CPE device can receive the topology-aware packets received by the switches corresponding to other CPE devices. Determining whether a CPE device has received a topology-aware packet from at least one other CPE device in the VLAN includes: in response to a CPE device receiving a topology-aware packet from another CPE device through its air port and WAN interface, determining that the CPE device has received a topology-aware packet from at least one other CPE device in the VLAN.

[0103] Taking CPE1 and CPE2 in Scenario 1 as examples, after CPE1 and CPE2 complete network registration, both send a topology-aware message to the Uu air interface and the WAN interface, respectively. Each topology-aware message corresponds one-to-one with a CPE device.

[0104] In some embodiments, a topology-aware message includes a source MAC address, a destination MAC address, and a payload. The source MAC address includes a hash of the user identification code, the destination MAC address includes a broadcast address, and the payload includes the user identification code of the CPE device. In some embodiments, the source MAC address further includes a unique identifier bit to identify that the source MAC address is locally unique. In some embodiments, the payload further includes any one of a status code, flag bits, and a message type identifier.

[0105] In some embodiments, a topology-aware message is an Ethernet message, a data frame conforming to the Ethernet protocol transmitted in a 5G LAN, used for data transmission between devices. It contains information such as source MAC address, destination MAC address, type / length field, data field, and frame check sequence.

[0106] In some embodiments, topology-aware messages are also referred to as Hello messages, or topology-aware Hello messages. The following description uses Hello messages as a specific implementation of topology-aware messages. For CPE1 and CPE2, the source MAC addresses of their Hello messages are 02-Hash40(IMSI_1) and 02-Hash40(IMSI_2), respectively. 02 is the unique identifier bit. The destination MAC address is the broadcast address, FF-FF-FF-FF-FF-FF. The payload indicates that the device is currently online, mainly including its IMSI value (i.e., the user identification code of the CPE device) and the StatusCode (device network access status, PDU establishment status, PDU rate and quality, etc.), as well as bits identifying the message type (i.e., message type identifier), such as "88-CC" (in some cases, this enables compatibility with LLDP protocol messages, facilitating identification by user LAN devices). Optionally, other bits (i.e., flag bits) may also be included, such as the Hello message transmission interval, etc.

[0107] Table 1 shows a Hello message format, where Hash40(IMSI) represents a 40-bit hash calculation of the IMSI number, the result of which, together with the first 8 bits "02", forms a 48-bit source MAC address. "02" indicates that this address is locally unique and is a globally unique MAC address used to distinguish the device's hardware network interface card. As mentioned earlier, the source MAC address of CPE1 is 02-Hash40(IMSI1), and the source MAC address of CPE2 is 02-Hash40(IMSI2).

[0108] Table 1:

[0109]

[0110] In some embodiments, after sending a Hello message, CPE1 and CPE2 enter a topology learning state. The device constructs forwarding address entries based on the received user messages and the topology-aware Hello messages, in conjunction with S-UPF (the forwarding table is updated periodically; the user switch has a storage unit for storing the forwarding table), but does not forward user service data. It should be noted that the user messages here are different from the Hello messages. The Hello message is a type of message proposed for topology awareness to perform loop detection.

[0111] Figure 5 This is a schematic diagram of a virtual stacking process 500 during 5G LAN PDU session establishment suitable for implementing embodiments of the present disclosure. The terminal and network are separated by dashed lines. The terminal corresponds to... Figure 2 The CPE devices CPE1 and CPE2 in the network include Figure 2 S-gNB1, SMF and S-UPF1 in the middle, and Figure 2 AMF, PCF, UDM, and DN are not shown in the diagram. (Reference) Figure 5 As shown, in step S501, when CPE1 and CPE2 send Hello messages to the Uu interface, it triggers CPE1 and CPE2 to send the first session request message, namely the PDU SessionEstablishmentRequest message, establishing the first PDU session for 5G-LAN services with S-gNB1, namely the first session PDU0, identified as IMSI_1 / PDU0 and IMSI_2 / PDU0 respectively. The first session PDU0 is mainly used for 5GC and CPE to perceive the user network topology and is not used for service data forwarding. The first session PDU0 is used to carry Hello messages. It should be noted that the first session PDU0 is a PDU proposed for loop detection. After completing topology awareness and virtual stacking, the CPE establishes other sessions to carry user services, such as the second session PDU1.

[0112] In some embodiments, the first session request message includes a single network slice selection assistance information (S-NSSAI) corresponding to the virtual network group to which the CPE device belongs and the data network name (DNN) of the target service, wherein the target service includes a Layer 2 service or a Layer 3 service. According to these embodiments, the CPE (each of CPE1 and CPE2) carries the S-NSSAI corresponding to its own VN group and the DNN corresponding to the subscribed 5G-LAN service in the PDUessionEstablishmentRequest message. Furthermore, the terminal carries the PDU session request type PDUessionType (including IPv4, IPv6, IPv4v6, Ethernet, and Unstructured) depending on whether the service type is a Layer 3 service or a Layer 2 service. Since the first session PDU0 is a Layer 2 service, the PDUessionType here is Ethernet.

[0113] In some embodiments, the CPE device generates a topology-aware identifier, which is used to indicate that the first session is used for topology-aware packets. According to these embodiments, for the first session PDU0, the CPE generates a specific topology-aware identifier, namely the PDUsessionID identifier, indicating that the PDU is used for user network topology awareness for virtual stacking purposes, which facilitates the network to formulate dedicated QoS and charging policies for PDU0.

[0114] Continue to refer to Figure 5 In step S502, after the AMF receives the PDUSSionEstablishmentRequest message through the N1 interface, it queries the NRF based on S-NSSAI and DNN, and selects the appropriate SMF to handle the 5G-LAN service control logic of CPE1 and CPE2.

[0115] It should be noted that both AMF and SMF network elements belong to the control plane network elements and can be used for message forwarding and routing.

[0116] In step S503, the AMF sends an Nsmf_PDUSession_CreateSMContextRequest message to the selected SMF to request the establishment of a PDU0 session context, carrying the DNN corresponding to the user's subscribed 5G-LAN service, as well as S-NSSAI, PDUssionType, PDUssionID and other relevant information.

[0117] In step S504, the SMF initiates session registration with the UDM and obtains the user's subscription information. If the 5G-LAN service subscriptions for the VN groups corresponding to the DNN and S-NSSAI requested by IMSI_1 and IMSI_2 are still valid, the SMF notifies the AMF that the session context has been successfully established.

[0118] In step S505, secondary authentication of the PDU session is performed according to service requirements. Step S505 is an optional step. After the user equipment (UE) completes the initial 5G access authentication, when it initiates a packet data unit (PDU) session establishment request for a specific data network (DN), the network side determines whether an additional authentication process is required for the UE based on factors such as service type and DNN, to ensure that the UE has the authority to access the services provided by that DN.

[0119] In step S506, the SMF obtains the QoS control policy, charging control policy, and UPF selection policy corresponding to the first session PDU0 from the PCF. The PCF recognizes that PDUSessionID is the first session PDU0 and can issue a higher QoS guarantee policy and a traffic call detail record (CDR) reduction charging policy to this PDU, thus avoiding traffic-based billing for the user.

[0120] In step S507, the UPF selects and updates the session policy. Since both CPE1 and CPE2 are registered and reside under S-gNB1, the SMF selects S-UPF1 as the common anchor UPF (PSA UPF) for their 5G-LAN services according to a certain policy.

[0121] In step S508, the SMF and S-UPF1 initiate an N4 session. The SMF identifies that CPE1 and CPE2 have the same DNN+S-NSSAI for initiating 5G-LAN services, meaning they belong to the same VN. Therefore, it instructs S-UPF1 to forward the 5G-LAN packets of both CPE1 and CPE2 through a local switch. The SMF, through the N4 interface, schedules S-UPF1 to establish the first session PDU0 with CPE1 and CPE2, and to establish a GTP-U (GPRS Tunneling Protocol for the user plane) tunnel related to S-gNB1. A connection is then established between the satellite base stations S-gNB1 and S-UPF1 for the virtual local area network.

[0122] In step S509, access-side resource establishment is completed, and the PDU session establishment result and uplink / downlink GTP-U tunnel information are sent out. Thus, combined with... Figure 2As shown, the Hello messages transmitted by CPE1 and CPE2 via IMSI_1 / PDU0 and IMSI_2 / PDU0 both reach S-UPF1. S-UPF1 writes the mapping between the two first session PDU0s and the source MAC address with the value 02-Hash40 (IMSI) into its own session table, for example, IMSI_1 / PDU0 / 02-Hash40 (IMSI_1) and IMSI_2 / PDU0 / 02-Hash40 (IMSI_2).

[0123] In step S510, the PDU session context and N4 session are updated.

[0124] In step S511, the Hello broadcast packet is transmitted and forwarded. S-UPF1 broadcasts Hello messages to users belonging to the same VN based on the local switch mechanism.

[0125] refer to Figure 2 Based on Hello message broadcasting, CPE2 receives Hello messages from CPE1 via the Uu air interface, and CPE1 receives Hello messages from CPE2 via the Uu air interface. Simultaneously, User Switch 1's P0 port receives Hello messages sent from CPE1's WAN port and floods them onto User Switch 2's ports via a stacking mechanism. After flooding, CPE2's WAN port can receive CPE1's Hello messages through User Switch 2's P0 port. Similarly, User Switch 2's P0 port receives Hello messages sent from CPE2's WAN port and floods them onto User Switch 1's ports via a stacking mechanism. After flooding, CPE1's WAN port can receive CPE2's Hello messages through User Switch 1's P0 port.

[0126] In step S512, the CPE performs loop detection. When it is detected that both CPE1 and CPE2 have received Hello messages from each other through the Uu port and WAN port, it can be determined that there is a loop between CPE1 and CPE2.

[0127] In step S513, S-UPF1 performs PDU forwarding table learning to facilitate subsequent operations on MAC entries in the second session.

[0128] Steps S501-S513 can be used as a specific implementation of how to determine in step S310 whether the CPE device has received a topology-aware message for perceiving the user network topology from at least one other CPE device in the virtual LAN.

[0129] It is understandable that when there are more CPE devices in the same VN, if it is detected that a certain CPE has received Hello messages from other CPE devices through the Uu port and WAN port, it can be determined that the CPE device has received Hello messages from at least one other CPE device in the virtual LAN. In step S320, loop information can be reported to the SMF network element to indicate that there is a loop in the virtual LAN, so that the SMF network element can initiate virtual stacking.

[0130] In some embodiments, loop information includes loop formation information (e.g., an indicator), which directly indicates the existence of a loop in the virtual local area network. In step S320, in response to determining that the CPE device has received a topology-aware message from at least one other CPE device in the virtual local area network, the CPE device reports the loop information to the SMF network element. This includes: the CPE device obtaining the user identification codes (IMSIs) of other CPE devices carried in the topology-aware message, and reporting the IMSIs of the other CPE devices along with the loop formation information to the SMF network element, causing the SMF network element to initiate virtual stacking of a second session following the first session for each CPE device in the loop. According to this embodiment, refer to... Figure 5 In step S514, CPE1 and CPE2 respectively store the IMSI number of the loop peer and report the loop formation information via NAS (Non-Access Stratum) messages (such as ULInformationTransfer), carrying the IMSI number of the peer. It should be noted that the peer refers to any CPE in the loop other than the current CPE. In step S515, S-gNB1 sends the loop formation information to the AMF network element via a ULNASTransport message. In step S516, the AMF network element then sends the loop formation information to the SMF via a PDU session context update. In step S517, after obtaining the loop formation information, the SMF instructs S-UPF1 to virtually stack the subsequent second session PDU1s (e.g., IMSI_1 / PDU1, IMSI_2 / PDU1) of IMSI_1 and IMSI_2. The second session can be a specific Ethernet service data PDU.

[0131] Step S518 is a virtual stacking step. For example, the SMF instructs S-UPF1 to release the establishment of PDU1 for IMSI_1 and block the establishment of PDU1 for IMSI_2. Alternatively, the SMF can also instruct CPE2 to block its WAN port. At this time, the Ethernet services of UE11, UE12, ..., UE1n under UserSwitch1 and User switch2 are all transmitted through IMSI_1 / PDU1. As shown in step S519, at this time, the second session PDU1 of CPE1 enters the forwarding state, and the second session PDU1 of CPE2 enters the blocking state.

[0132] according to Figure 5 Steps S501-S518, as shown, describe how, after the first session PDU0 is established, a first session request is sent from a CPE in the same VN group. The network end and the terminal CPE perceive the user network topology through the first session PDU0 carrying Hello messages, and after S-UPF1 broadcasts Hello messages, the CPE detects a loop through loop detection, and the SMF network element initiates virtual stacking of the second session PDU1, thereby breaking the loop. This embodiment solves the loop problem in virtual LANs without requiring additional STP protocol execution or new network control devices.

[0133] Figure 6 An exemplary flowchart of a satellite communication method 600 according to an embodiment of this disclosure is shown. (Refer to...) Figure 6 As shown, in some embodiments, the satellite communication method 600 includes:

[0134] Step S610: The CPE device periodically sends topology-aware messages through the first session. In response to the CPE device not receiving topology-aware messages from other CPE devices through the WAN interface, it determines that the loop is broken.

[0135] Step S620: The CPE device deletes the user identification codes of other CPE devices in the loop besides itself.

[0136] Step S630: The CPE device sends a loop break message to the SMF network element. The loop break message indicates that the loop has been broken, causing the SMF network element to instruct the UPF network element to perform a stack split. Here, the term "stack split" refers to breaking the previously established virtual stack.

[0137] In step S610, this disclosure does not limit the specific settings for the periodicity. A broad understanding of periodicity includes continuously executing the action of sending the corresponding topology-aware message through the first session. Periodicity can also be understood as an interval of a fixed time, such as 1 minute. Continuing with the example from Scenario 1, CPE1 and CPE2 send the corresponding topology-aware message through the first session every 1 minute. In some embodiments, CPE1 and CPE2 may have timers. When the timer expires and CPE1 and CPE2 cannot receive Hello messages from other CPE devices through their own WAN ports, it indicates that the loop has been broken.

[0138] In step S620, CPE1 and CPE2 delete the IMSI number of the peer and report loop break information via NAS messages (e.g., ULInformationTransfer), carrying the IMSI of the peer in the loop. After obtaining the loop break information, SMF issues stack split instructions to S-UPF1 and S-UPF2 respectively to split the stack of IMSI_1 / PDU1 and IMSI_2 / PDU1. In one example, the stack split includes: SMF instructing S-UPF1 to restore the establishment of IMSI_2 / PDU1 or SMF instructing CPE2 to restore its WAN port state to forwarding, while SMF instructs S-UPF1 to copy IMSI_1 / PDU1 to IMSI_2 / PDU1. (Reference) Figure 2 As shown, at this time, Ethernet services sent to UE11, UE12, ..., UE1n within a short period of time will be carried on IMSI_1 / PDU1 and IMSI_2 / PDU1. However, due to the stacking split of User switch1 and User switch2, Userswitch2 cannot receive Ethernet packets from UE11 and UE12's 00:00:00:00:00:02 port, and User switch1 cannot receive Ethernet packets from UE12's 00:00:00:00:00:03 port and UE1n. When the MAC entries of S-UPF1, User switch1, and Userswitch2 time out, they will be refreshed. At this time, IMSI_1 / PDU1 will only contain sessions from UE11 and UE12's 00:00:00:00:00:02 port, and IMSI_2 / PDU1 will only contain sessions from UE12's 00:00:00:00:00:03 port and UE1n.

[0139] Figure 7 An exemplary flowchart of a satellite communication method 700 according to an embodiment of the present disclosure is shown. (Refer to...) Figure 7 As shown, in some embodiments, after determining that the loop is broken, the satellite communication method 700 includes:

[0140] Step S710: In response to the CPE device receiving topology-aware messages from other CPE devices again via the WAN interface, it is determined that the loop has re-formed; and

[0141] Step S720: The CPE device sends loop information to the SMF network element, causing the SMF network element to initiate virtual stacking.

[0142] Continuing with the example from Scenario 1, in step S710, when CPE1 and CPE2 receive each other's Hello messages again on the WAN port, it is determined that the loop has re-formed. In this example, since the VN only includes two CPEs, namely CPE1 and CPE2, the re-formed loop is still the previously broken loop, and therefore can also be called loop recovery. In other examples, when multiple CPEs and UPFs are included, the re-formed loop may not be the same loop as the previously broken loop.

[0143] In step S720, the CPE sends loop formation information to the SMF, which instructs S-UPF1 to merge the MAC entries for IMSI_1 / PDU1 and IMSI_2 / PDU1 sessions. In one example, the MAC entries can be merged into the IMSI_1 / PDU1 sessions to be allowed. S-UPF1 is then instructed to release the establishment of IMSI_1's PDU1 and block the establishment of IMSI_2's PDU1. Alternatively, the SMF instructs CPE2 to re-block its WAN port. Additionally, User switch1 and User switch2 will automatically perform stack recovery and MAC entry merging.

[0144] In some embodiments, the satellite communication method 300 further includes: in response to a CPE device receiving a topology-aware message received by a switch corresponding to another CPE device via a WAN interface, the CPE device no longer sends the topology-aware messages received by the other CPE device via the WAN interface to the UPF network element via the air port. According to these embodiments, when a loop is detected, even if CPE1 and CPE2 no longer send Hello messages received from the peer CPE via the WAN port to S-UPF1 via the Uu port, a broadcast storm can be prevented from occurring in the Hello messages on the first session PDU0.

[0145] In some embodiments, the loop information may include not only loop formation information generated by the CPE device after loop monitoring, but also topology-aware messages received by the CPE device. In step S320, in response to determining that the CPE device has received a topology-aware message from at least one other CPE device in the VLAN, reporting the loop information to the SMF network element includes: the CPE device forwarding the received topology-aware message to the SMF network element, causing the SMF network element to determine the existence of a loop in the VLAN based on the topology-aware message, and initiating virtual stacking of a second session following the first session for each CPE device in the loop. According to these embodiments, determining the existence of a loop in the VLAN is performed by the SMF.

[0146] The above content mainly describes the specific implementation method when satellite communication methods are applied to CPE devices in a virtual local area network. Among them, Figure 2 , Figure 4 and Figure 5 This can be used to illustrate the specific implementation methods when satellite communication methods are applied to SMF, UPF, and AMF in a Virtual Local Area Network (VLAN). The specific implementation methods for applying satellite communication methods to SMF, UPF, and AMF in a VLAN will be described below. All the interactive steps involved can be fully understood based on the foregoing text and related figures, which can be used to illustrate the specific implementation methods when satellite communication methods are applied to SMF, UPF, and AMF in a VLAN; repeated content will not be elaborated upon.

[0147] Figure 8 An exemplary flowchart of a satellite communication method 800 according to an embodiment of the present disclosure is shown. The satellite communication method 800 is applied to an SMF network element in a virtual local area network. (See reference...) Figure 8 As shown, the satellite communication method 800 of this embodiment includes:

[0148] Step S810: In response to receiving loop information from one of the multiple CPE devices, indicating directly or indirectly that a loop exists in the virtual local area network, the SMF network element initiates virtual stacking, wherein the virtual local area network includes satellite network equipment and multiple CPE devices, and the satellite network equipment includes the SMF network element.

[0149] In some embodiments, the satellite network device further includes an AMF network element and a UPF network element, and method 800 further includes: the SMF network element receiving a first session request message from any one of the plurality of CPE devices from the AMF network element; in response to receiving the first session request message, the SMF network element instructs any one of the CPE devices to establish a first session with the UPF network element, the first session carrying topology-aware messages for sensing the user network topology. These embodiment steps may correspond to... Figure 5Steps S501-S504 in the process.

[0150] In some embodiments, the SMF network element in step S810 initiates virtual stacking, including: the SMF network element initiates virtual stacking for a second session following the first session of each CPE device in the loop.

[0151] Figure 9 An exemplary flowchart illustrating the initiation of virtual stacking by an SMF network element in a satellite communication method 900 according to an embodiment of this disclosure is shown. (See also: [link to document]) Figure 9 As shown, the method 900 of this embodiment includes:

[0152] Step S910: The SMF network element selects the target CPE device from the various CPE devices in the loop;

[0153] Step S920: The SMF network element instructs the UPF network element to block the establishment of a second session between other CPE devices (excluding the target CPE device) and the UPF network element, or the SMF network element instructs other CPE devices (excluding the target CPE device) to block the corresponding WAN interface.

[0154] According to steps S910-S920, the SMF network element first selects a target CPE device from multiple CPE devices. During the virtual stacking process, it is equivalent to stacking the forwarding links of other CPE devices into the forwarding link of the target CPE device, thereby realizing the result of virtualizing the user into a single link and solving the loop problem.

[0155] Figure 10 An exemplary flowchart illustrating the SMF's selection of a target CPE device in a satellite communication method according to an embodiment of this disclosure is shown. (Refer to...) Figure 10 As shown, in some embodiments, in step S910, the SMF network element selects the target CPE device from each CPE device in the loop, including:

[0156] Step S911: Select the CPE device with the highest service level among all CPE devices as the target CPE device; or,

[0157] Step S912: Select the CPE device with the smallest user identification code among all CPE devices as the target CPE device; or,

[0158] Step S913: Select the CPE device with the highest user equipment capability among all CPE devices as the target CPE device.

[0159] In some embodiments, the priorities of steps S911-S913 are arranged from high to low, with service level having the highest priority, followed by the size of the user identification code, and finally the user equipment capabilities.

[0160] Continuing with the example from Scenario 1, when the SMF initiates virtual stacking, the SMF instructs S-UPF1 to select either IMSI_1 / PDU1 or IMSI_2 / PDU1 for the blocking operation. The following election strategy can be adopted:

[0161] Prioritize comparing the Service Level Agreements (SLAs) of IMSI_1 and IMSI_2. SLAs include, but are not limited to, QoS parameters such as session-AMBR (per session aggregate maximum bit rate), MFBR (maximum flow bit rate), and GFBR (guaranteed flow bit rate). When a user activates their SIM card, these parameters are configured in the UDM by the BOSS (Business Operations Support System). The SMF can then query the UDM and instruct the UPF. If the UDM does not configure a service level or the levels are the same, a simple comparison of IMSI sizes can be used, with smaller IMSIs having higher priority. Optionally, the SMF can also select based on the UECapability Information reported by the CPE during registration; CPEs with higher UE capabilities have higher priority.

[0162] By using the above method to select the target CPE device from multiple CPE devices, the normal communication function of the forwarding link after virtual stacking can be ensured.

[0163] In some embodiments, in step S810, the loop information received by the SMF includes a topology-aware message received by the CPE device from at least one other CPE device in the virtual LAN for sensing the user network topology. The method further includes: before initiating virtual stacking, the SMF network element determines, based on the topology-aware message, that a loop has formed between the CPE device and at least one other CPE device. According to this embodiment, the CPE device does not directly send loop formation information to the SMF, but instead sends a Hello message to the SMF. The SMF can determine that a loop has formed upon receiving the Hello message.

[0164] Figure 11 An exemplary flowchart of a satellite communication method 1100 according to an embodiment of the present disclosure is shown. (See reference...) Figure 11 As shown, in some embodiments, when the SMF determines whether a loop has formed, the satellite communication method 1100 includes:

[0165] Step S1110: The SMF network element monitors loop information;

[0166] Step S1120: In response to the absence of loop information within a predetermined time period, the SMF network element determines that the loop is broken; and

[0167] Step S1130: In response to the determination that the loop is broken, the SMF network element initiates a stack split.

[0168] SMF may include a timer to continuously or intermittently monitor loop information from CPE devices. This loop information can be loop formation information or topology-aware messages. Loop formation information directly indicates the existence of a loop in the VLAN. Regardless of the type of loop information, if no loop information is received within a predetermined time period, the SMF determines that the previously formed loop has been broken, thereby initiating a stack split.

[0169] The virtual stacking and stack splitting discussed here can be found in the previous explanation.

[0170] In some embodiments, the satellite communication method 1100 further includes: in response to receiving loop information again after not receiving loop information within a predetermined time period, the SMF network element determines that the loop has been re-formed; and in response to determining that the loop has been re-formed, the SMF network element initiates virtual stacking.

[0171] In some embodiments, the satellite communication method 800 further includes: in response to receiving loop break information indicating a loop break from a CPE device in the loop, an SMF network element initiates a stack split. According to this embodiment, the loop break information may be the loop break information generated by the CPE device in step S630 above.

[0172] In some embodiments, stack splitting includes: the SMF network element instructing the UPF network element to resume establishing a second session with other CPE devices besides the target CPE device; or, the SMF network element instructing the WAN interface of other CPE devices besides the target CPE device to resume forwarding mode; and the SMF network element instructing the UPF network element to copy the second session of the target CPE device to the second session of other CPE devices.

[0173] In some embodiments, the satellite communication method 800 further includes: in response to the failure of the air-to-ground wireless link of the target CPE device, the SMF network element sends a session deletion instruction to the UPF network element, causing the UPF network element to delete the session of the target CPE device; the SMF network element instructs the UPF network element to resume establishing a second session with other CPE devices in the loop besides the target CPE device; or the SMF network element instructs the WAN interface of other CPE devices in the loop besides the target CPE device to return to forwarding mode; and the SMF network element instructs the UPF network element to copy the second session of the target CPE device to the second session of other CPE devices.

[0174] Continuing with the example from Scenario 1, in the case of Radio Link Failure on CPE1's Uu interface, the AMF directly instructs the SMF to delete all PDUs of IMSI_1. Simultaneously, the SMF instructs S-UPF1 to delete the session and instructs CPE2 to either re-establish the IMSI_2 / PDU1 session or restore the WAN port to forwarding mode and copy IMSI_1 / PDU1 to IMSI_2 / PDU1. Data transmission for UE11, UE12, ..., UE1n will all be carried through CPE2.

[0175] In some embodiments, the satellite communication method 800 further includes: the SMF network element obtaining control policies corresponding to a first session of multiple CPE devices from the PCF device, the control policies including any one of QoS control policies, charging control policies, and UPF selection policies; and in response to the first session including a topology-aware identifier, the SMF network element issuing a higher-level control policy to the first session. According to these embodiments, the SMF obtains the QoS control policy, charging control policy, and UPF selection policy corresponding to the first session PDU0 from the PCF. Here, the PCF identifies the topology-aware identifier PDUSessionID as PDU0, and can issue a higher-level QoS guarantee policy and a traffic call detail record (CDR) reduction charging policy to this PDU, avoiding traffic billing for the user.

[0176] In some embodiments, the satellite communication method 800 further includes: establishing a connection between the first port of the SMF network element and the first port of the UPF network element, wherein the SMF network element designates the UPF network element to forward service packets from multiple CPE devices. In some embodiments, the first port is an N4 interface. The SMF schedules S-UPF1 to forward service packets from CEP1 and CPE2 through the N4 interface. The N4 interface can be referenced from [reference needed]. Figure 2 As shown.

[0177] In some embodiments, the satellite communication method 800 further includes: the SMF network element scheduling the UPF network element to establish a first session with multiple CPE devices through a first port, and establishing a tunnel connection between the UPF network element and the satellite base station. According to these embodiments, the SMF schedules S-UPF1 with CPE1 and CPE2 through the N4 interface to complete the establishment of the PDU0 session and the establishment of the GTP-U tunnel related to S-gNB1.

[0178] The preceding text mainly focuses on Figure 2The example in Scenario 1, which includes a virtual local area network (VLAN) formed by CPE1, CPE2, S-gNB1, and S-UPF1, is used for illustration. In Scenario 2, assuming the satellite network equipment includes a first satellite and a second satellite, the first satellite includes a first onboard base station and a first UPF network element, and the second satellite includes a second onboard base station and a second UPF network element, among multiple CPE devices belonging to the same virtual network group, at least one CPE device is used to establish a first session with the first UPF network element, and at least one CPE device is used to establish a first session with the second UPF network element. Method 800 further includes: binding the first port of the first UPF network element and the first port of the second UPF network element to instruct the first UPF network element and the second UPF network element to establish a connection through the second port to achieve packet forwarding. Here, binding the first port of the first UPF network element and the first port of the second UPF network element to the SMF network element means that the SMF treats the first port of the first UPF network element and the first port of the second UPF network element as a group, and stack-related signaling is only sent within this group.

[0179] refer to Figure 2 As shown, in a specific example, the first port is the N4 interface, and the second port is the N19 interface. The CPE devices in Scenario 2 include CPE3 and CPE4. CPE3 establishes 5G-LAN related PDUs with S-UPF1, and CPE4 establishes 5G-LAN related PDUs with S-UPF2. Both S-UPF1 and S-UPF2 learn and store relevant forwarding table entries. The SMF recognizes that CPE3 and CPE4 belong to the same VN and binds the SMF to the N4 interfaces of S-UPF1 and S-UPF2. Through this bound N4 interface, it instructs S-UPF1 and S-UPF2 to establish an N19 connection to forward their 5G-LAN packets. Subsequent scheduling of 5G-LAN services for this VN group by the SMF will interact with S-UPF1 and S-UPF2 through this bound N4 interface.

[0180] In Scenario 2, in some embodiments, the SMF network element selects a target CPE device from various CPE devices in the loop, including: the SMF network element selects the CPE device corresponding to the one with the shorter feeder link between the first satellite base station and the second satellite base station as the target CPE device.

[0181] In scenario two, combined with Figure 2 In the specific example shown, during the virtual stack setup process, the SMF can choose between IMSI_3 / PDU1 or IMSI_4 / PDU1 for the blocking operation using the following election strategy:

[0182] Comparing the feeder links (links established between the satellite and the ground gateway) of S-gNB1 and S-gNB2, the PDU with a feeder link has a higher priority. If the feeder link conditions are the same, the priority is determined by referring to the IMSI priority and the optional UECapabilityInformation mentioned above. If both have feeder links, since longer links result in lower transmission efficiency, the CPE device corresponding to the shorter feeder link is selected as the target CPE device to obtain higher transmission efficiency.

[0183] In some embodiments, under scenario three, the satellite network equipment includes UPF network elements on multiple satellites, and a loop exists in the space-based network formed by the UPF network elements on these multiple satellites through inter-satellite links. The virtual stacking includes:

[0184] The SMF network element binds to the first port of the UPF network element in the loop and instructs each UPF network element to perform a stacking role election. The stacking role election includes: determining whether a UPF network element is a master node or a standby node according to priority rules, and selecting other UPF network elements as slave nodes. The standby node is elected as the master node if the master node leaves the loop.

[0185] The SMF network element instructs the master node to block the second port in one direction; and

[0186] In response to the disconnection of the inter-satellite link or the offline status of the CPE device causing the corresponding UPF network element to exit the loop, the SMF network element instructs the master node to restore the blocked second port.

[0187] Combination Figure 2 In the specific example shown in Scenario 3, after the SMF detects the formation of the space-based loop, it binds the N4 interfaces of all S-UPFs in the loop. Based on these bound N4 interfaces, it instructs each S-UPF to perform stacking role election and topology construction. This can be done using mature methods such as Discovery messages, MAD messages, and PRP / HSR messages. Alternatively, it can refer to Scenario 2, where, based on the corresponding S-gNB power supply link, the S-UPF corresponding to the S-gNB with the power supply link is prioritized as the Master node or Standby node, and other S-UPFs are selected as Slave nodes. The SMF will instruct the selected Master S-UPF to block its N19 interface in one direction.

[0188] refer to Figure 2 The inter-satellite links of the UPF in the loop have two directions, for example, S-UPF1 to one direction ( Figure 2 The left side of the image connects to the S-UPF4 via the N19 interface, and the other side ( Figure 2 (The right side of the image) is connected to S-UPF2 via the N19 interface. When the SMF network element instructs the master node to block the second port in one direction, it means the SMF instructs the master node's UPF network element to block the N19 interface in one of the two directions.

[0189] When the ISL of a satellite in the loop is disconnected or the CPE under an S-gNB goes offline, causing the corresponding S-UPF to leave the loop, the SMF instructs the Master S-UPF to restore its blocked N19 interface. When the Master S-UPF leaves the loop, the remaining S-UPFs elect the Standby S-UPF as the Master S-UPF. If the loop still exists, the N19 interface of that S-UPF in one direction is blocked.

[0190] In scenario three, multiple S-UPFs form a space-based loop via ISL links and forward 5G-LAN packets through port N19.

[0191] According to the above embodiment, after the network detects a loop, it blocks redundant service PDUs or N19 interfaces based on a certain priority decision strategy and merges the PDU forwarding table entries of the UPF. After the loop is broken, the network restores the redundant PDUs or N19 interfaces and copies the PDU forwarding table entries of the UPF. The network does not modify the existing forwarding topology of the user's existing LAN.

[0192] The following further explains some characteristics of Scenario 2.

[0193] Compared to Scenario 1, the registration process between the CPE and the network is similar in Scenario 2. However, CPE3 establishes 5G-LAN related PDUs with S-UPF1, and CPE4 establishes 5G-LAN related PDUs with S-UPF2. Both S-UPF1 and S-UPF2 learn and store relevant forwarding table entries. The SMF recognizes that CPE3 and CPE4 belong to the same VN and binds the SMF to the N4 interfaces of S-UPF1 and S-UPF2. Through this binding N4 interface, it instructs S-UPF1 and S-UPF2 to establish an N19 connection to forward their 5G-LAN packets. Subsequent scheduling of 5G-LAN services for this VN group by the SMF will interact with S-UPF1 and S-UPF2 through this binding N4 interface.

[0194] In Scenario 2, the processing flow after the loop is broken is similar to that in Scenario 1, but the SMF will copy IMSI_3 / PDU1 from S-UPF1 to IMSI_4 / PDU1 on S-UPF2. After the loop is restored, the SMF will merge the session MAC entries for IMSI_3 / PDU1 and IMSI_4 / PDU1 on S-UPF1 and S-UPF2.

[0195] In Scenario 2, the handling mechanism for wireless link timeout is similar to that in Scenario 1.

[0196] For Scenario 1 and Scenario 2, management devices within the existing user LAN can monitor the online status of CPE terminals and the establishment and operation status (speed, quality, etc.) of subsequent user service PDUs by listening to the Hello messages of the CPE, thereby facilitating the operation and maintenance management of the private overlay network.

[0197] Figure 12 An exemplary flowchart of a satellite communication method 1200 according to an embodiment of the present disclosure is shown. The satellite communication method 1200 is applied to a UPF network element in a Virtual Local Area Network (VLAN). Reference Figure 12 As shown, the satellite communication method 1200 of this embodiment includes:

[0198] Step S1210: In response to receiving a virtual stacking command from an SMF network element, the UPF network element performs virtual stacking of multiple CPE devices in the loop of the virtual LAN, wherein the virtual LAN includes satellite network equipment and multiple CPE devices, and the satellite network equipment includes the UPF network element.

[0199] In some embodiments, reference Figure 2 As shown, each CPE device communicates with a corresponding existing LAN device. The existing LAN devices include user switches, and the CPE devices include an air port for communicating with the corresponding satellite base station and a wide area network interface for communicating with the corresponding switch. The satellite communication method 1200 also includes:

[0200] A first session is established between the UPF network element and each CPE device to carry topology-aware messages, which are used to perceive the user's network topology; and

[0201] UPF network elements broadcast topology-aware messages to multiple CPE devices via air ports;

[0202] Among them, the UPF network element performs virtual stacking of multiple CPE devices in the loop of the virtual LAN, including: the UPF network element performs virtual stacking of the second session after the first session of multiple CPE devices.

[0203] In some embodiments, the satellite communication method 1200 further includes: the UPF network element virtually stacking a second session after the first session of multiple CPE devices, including: the UPF network element blocking the establishment of a second session between other CPE devices (excluding the target CPE device) and the UPF network element, wherein the target CPE device is a CPE device selected by the SMF network element from multiple CPE devices.

[0204] In some embodiments, the UPF network element may instruct the second session of the target CPE device to enter forwarding mode, and the second sessions of other CPE devices besides the target CPE device to enter blocking mode. In some embodiments, the satellite communication method 1200 further includes: in response to receiving a stack split instruction from the SMF network element, the UPF network element performs a stack split, including:

[0205] UPF network elements resume establishing a second session with other CPE devices besides the target CPE device; and

[0206] The UPF network element copies the second session of the target CPE device to the second session of other CPE devices.

[0207] In some embodiments, the satellite communication method 1200 further includes: in response to the failure of the air-to-ground wireless link of the target CPE device, the UPF network element receives a session deletion instruction from the SMF network element, and the UPF network element deletes the session of the target CPE device;

[0208] UPF network elements resume establishing a second session with other CPE devices besides the target CPE device; and

[0209] The UPF network element copies the second session of the target CPE device to the second session of other CPE devices.

[0210] In some embodiments, before the UPF network element broadcasts topology-aware messages to multiple CPE devices through the air port, the method further includes: in response to the UPF network element receiving its respective first session from multiple CPE devices, the UPF network element writes the received first session and the source address in the corresponding topology-aware message into its own session table.

[0211] Figure 13 An exemplary flowchart of a satellite communication method 1300 according to an embodiment of the present disclosure is shown. The satellite communication method 1300 is applied to an AMF network element in a virtual local area network. (See reference...) Figure 13 As shown, the satellite communication method 1300 of this embodiment includes:

[0212] Step S1310: The AMF network element receives the first session request message from the CPE device through the third port;

[0213] Step S1320: In response to the first session request message, the AMF network element sends a request to establish the first session to the selected SMF network element, so that the SMF network element instructs the CPE device and the UPF network element to establish a first session for carrying topology-aware messages. The topology-aware messages are used to perceive the user network topology. The virtual LAN includes satellite network devices and multiple CPE devices. The satellite network devices include AMF network elements, SMF network elements and UPF network elements.

[0214] In some embodiments, the first session request message includes a single network slice selection aid information (S-NSSAI) corresponding to the virtual network group to which the CPE device belongs and the data network name (DNN) of the target service. After the AMF network element receives the first session request message from the CPE device through the third port, it further includes: querying the network storage function NRF network element according to the single network slice selection aid information and the data network name of the target service, and selecting the SMF network element to process the service control logic of the CPE device.

[0215] In some embodiments, the third port is the N1 interface.

[0216] For example, in the example of Scenario 1 described above, after the AMF receives the PDUSESSIONEstablishmentRequest message through the N1 interface, it queries the NRF based on S-NSSAI and DNN, and selects the appropriate SMF to handle the 5G-LAN service control logic of CPE1 and CPE2.

[0217] In some embodiments, the satellite communication method 1300 further includes:

[0218] The AMF network element receives a registration message from the CPE device through the satellite's onboard base station. The registration message includes a first tag, which is used to indicate that the CPE device supports the target service.

[0219] AMF network elements send feedback messages to CPE devices through satellite-based base stations. The feedback messages include a second tag, which indicates that the satellite supports the target service, enabling the CPE devices and the satellite to establish a virtual local area network.

[0220] To address the shortcomings of existing 5G-LAN service user plane forwarding loop avoidance technologies, this disclosure proposes a virtual stacking solution for user plane forwarding functions. This virtualizes the overlay network forwarding link as a single instance of the existing user network, eliminating the need for additional STP protocol execution or new network control equipment. This solution effectively resolves potential loop issues when the 5G-LAN overlay network connects to the existing user LAN. Compared to existing technologies, this disclosure reduces the computational and energy consumption of satellite payloads. Simultaneously, it decouples the 5G-LAN overlay network from the existing user LAN, ensuring that overlay network topology changes caused by CPEs and ISLs do not affect normal forwarding within the existing user LAN. Furthermore, this disclosure eliminates the need for additional network control equipment in the existing core network, minimizing modifications and resolving network loop issues before network storms occur, thus preventing impacts on network traffic forwarding performance.

[0221] Figure 14 This is a simplified block diagram of a device 1400 suitable for implementing embodiments of the present disclosure. For example, a network device and / or a terminal device may be implemented by device 1400. As shown, device 1400 includes one or more processors 1410, one or more memories 1420 coupled to processor 1410, and one or more communication modules 1440 coupled to processor 1410.

[0222] Communication module 1440 is used for bidirectional communication. Communication module 1440 has at least one antenna to facilitate communication. The communication interface can represent any interface necessary for communication with other network elements.

[0223] Processor 1410 can be of any type suitable for a local technology network, and as a non-limiting example, can include one or more of the following: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), and processor based on a multi-core processor architecture. Device 1400 can have multiple processors, such as application-specific integrated circuit chips, which are timely driven to a clock that synchronizes with the main processor.

[0224] Memory 1420 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 1424, electrically programmable read-only memory (EPROM), flash memory, hard disk, optical disc (CD), digital video disc (DVD), and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 1422 and other volatile memories that do not persist during power-off periods.

[0225] Computer program 1430 includes computer-executable instructions that are executed by a associated processor 1410. Program 1430 may be stored in ROM 1424. Processor 1410 may perform any appropriate actions and processes by loading program 1430 into RAM 1422.

[0226] Embodiments of this disclosure can be implemented via program 1430, enabling device 1400 to execute reference... Figures 3-13 Any process disclosed herein. Embodiments of this disclosure may also be implemented in hardware or by a combination of software and hardware.

[0227] In some embodiments, program 1430 may be tangibly contained in a computer-readable medium, which may be contained in device 1400 (e.g., memory 1420) or other storage device accessible to device 1400. Device 1400 may load program 1430 from the computer-readable medium into RAM 1422 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Program 1430 is stored on the computer-readable medium.

[0228] Generally, the various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while others may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of this disclosure are shown and described as block diagrams, flowcharts, or other graphical representations, it should be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0229] This disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in a program module, which execute in a device on a target real or virtual processor to perform the aforementioned references. Figure 3 The method described in 300 and / or as referred above Figures 6-9 , Figures 11-13The methods described are 600, 700, 800, 900, 1100, 1200, and 1300. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of a program module can be combined or separated as needed. The machine-executable instructions used in a program module can execute locally or in a distributed device. In a distributed device, the program module can reside in both local and remote storage media.

[0230] Program code used to perform the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code may be executed entirely on a machine, partially on a machine, partially on a remote machine, partially on a remote machine, or entirely on a remote machine or server as a standalone software package.

[0231] In the context of this disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, etc.

[0232] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or apparatuses, or any suitable combination thereof. More specific examples of computer-readable storage media include electrical connections having one or more wires, portable computer floppy disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0233] Furthermore, although the operations are described in a specific order, this should not be construed as requiring that these operations be performed in the specific order or sequence shown, or that all of the operations shown be performed to obtain the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the foregoing discussion, these details should not be construed as limiting the scope of this disclosure, but rather as descriptions of features specific to particular embodiments. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0234] Although this disclosure has been described in language specific to structural features and / or methodological behavior, it should be understood that this disclosure as defined in the appended claims is not necessarily limited to the specific features or behaviors described above. Rather, the specific features and actions described above are disclosed as exemplary forms for implementing the claims.

[0235] It should be fully understood that the use of personally identifiable information should comply with privacy policies and practices generally considered to meet or exceed industry or governmental requirements for protecting user privacy. In particular, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to the user.

Claims

1. A satellite communication method applied to a CPE device in a virtual local area network, comprising: determining whether the CPE device receives a topology-aware message for sensing a user network topology from at least one other CPE device in the virtual local area network, wherein the virtual local area network comprises a satellite network device and a plurality of CPE devices, and the satellite network device comprises an SMF network element; and in response to determining that the CPE device receives the topology-aware message from at least one other CPE device in the virtual local area network, reporting loop information to the SMF network element, the loop information directly or indirectly indicating that there is a loop in the virtual local area network, so that the SMF network element initiates a virtual stack; wherein the satellite network device further comprises an AMF network element and a UPF network element, and each of the CPE devices sends a first session request message to the AMF network element, so that the AMF network element initiates establishment of a first session between each of the CPE devices and the UPF network element for carrying the topology-aware message, wherein the determining whether the CPE device receives the topology-aware message from at least one other CPE device in the virtual local area network comprises: in response to the CPE device receiving the topology-aware message of the other CPE device, determining that the CPE device receives the topology-aware message from at least one other CPE device in the virtual local area network.

2. The satellite communication method of claim 1, wherein, The satellite network device further comprises a satellite-based base station, each of the CPE devices is communicatively connected to a corresponding stock LAN device, the stock LAN device comprises a switch, and each of the CPE devices comprises a space port for communicatively connecting to the corresponding satellite-based base station and a wide area network interface for communicatively connecting to the corresponding switch, each of the CPE devices sends the first session request message to the AMF network element through the space port, each of the CPE devices sends the respective topology-aware message to the corresponding switch through the wide area network interface, wherein the corresponding switch of each of the CPE devices is set to a stacking mode, so that the corresponding switch of each of the CPE devices can receive the topology-aware message received by the corresponding switch of the other CPE device, wherein the determining whether the CPE device receives the topology-aware message from at least one other CPE device in the virtual local area network comprises: in response to the CPE device receiving the topology-aware message of the other CPE device through the space port and the wide area network interface, determining that the CPE device receives the topology-aware message from at least one other CPE device in the virtual local area network.

3. The satellite communication method of claim 2, wherein, The loop information comprises loop formation information, the loop formation information directly indicating that there is a loop in the virtual local area network, and the reporting loop information to the SMF network element in response to determining that the CPE device receives the topology-aware message from at least one other CPE device in the virtual local area network comprises: The CPE device acquires the user identifier of the other CPE device carried in the topology awareness message, and reports the user identifier of the other CPE device and the loop forming information to the SMF network element, so that the SMF network element initiates virtual stacking of the second session after the first session of each CPE device in the loop.

4. The satellite communication method of claim 3, wherein, Further comprising: The CPE device periodically sends the topology awareness message through the first session, and determines that the loop is disconnected in response to the CPE device being unable to receive the topology awareness message of the other CPE device through the wide area network interface; The CPE device deletes the user identifier of the other CPE device in the loop except itself; And The CPE device sends loop disconnection information to the SMF network element, the loop disconnection information indicating that the loop is disconnected, so that the SMF network element instructs the UPF network element to split the stacking.

5. The satellite communication method of claim 4, wherein, After determining that the loop is disconnected, further comprising: In response to the CPE device receiving the topology awareness message of the other CPE device through the wide area network interface again, it is determined that the loop is formed again; and The CPE device sends loop information to the SMF network element, so that the SMF network element initiates virtual stacking.

6. The satellite communication method of claim 2, wherein, The loop information includes the topology awareness message received by the CPE device, and the loop information is reported to the SMF network element in response to determining that the CPE device receives the topology awareness message from at least one other CPE device in the virtual local area network, comprising: The CPE device forwards the received topology awareness message to the SMF network element, so that the SMF network element determines that there is a loop in the virtual local area network according to the topology awareness message, and initiates virtual stacking of the second session after the first session of each CPE device in the loop.

7. The satellite communication method of claim 2, wherein, Further comprising: In response to the CPE device receiving the topology awareness message received by the switch corresponding to the other CPE device through the wide area network interface, the CPE device no longer sends the topology awareness message of the other CPE device received through the wide area network interface to the UPF network element through the dummy port.

8. The satellite communication method of any one of claims 2-7, wherein, The dummy port is a Uu air interface, and the wide area network interface is a WAN port.

9. The satellite communication method of any one of claims 2-7, wherein, Before determining whether the CPE device receives the topology awareness message from at least one other CPE device in the virtual local area network, further comprising: The CPE device sends a registration message to the AMF network element through the satellite base station, and the registration message includes a first label, the first label being used to indicate that the CPE device supports target services; and The CPE device receives a feedback message from the AMF network element, and the feedback message includes a second label, the second label being used to indicate that the satellite supports the target services, so that the CPE device and the satellite establish a virtual local area network.

10. A satellite communication method applied to an SMF network element in a virtual local area network, comprising: in response to receiving loop information directly or indirectly indicating existence of a loop in the virtual local area network from a CPE device of the plurality of CPE devices, the SMF network element initiates virtual stacking, wherein the virtual local area network comprises a satellite network device and the plurality of CPE devices, the satellite network device comprising the SMF network element; the satellite network device further comprises an AMF network element and a UPF network element, the method further comprises: the SMF network element receives a first session request message from any one CPE device of the plurality of CPE devices from the AMF network element; in response to receiving the first session request message, the SMF network element instructs the any one CPE device to establish a first session with the UPF network element, the first session carrying topology awareness messages for perceiving user network topology; the SMF network element initiates virtual stacking, comprising: the SMF network element initiates virtual stacking of a second session after the first session for each CPE device in the loop, the second session for carrying service data.

11. The satellite communication method of claim 10, wherein, the SMF network element initiates virtual stacking of a second session after the first session for each CPE device in the loop, comprising: the SMF network element selects a target CPE device from the CPE devices in the loop; and the SMF network element instructs the UPF network element to block establishment of a second session between the UPF network element and other CPE devices except the target CPE device, or the SMF network element instructs other CPE devices except the target CPE device to block corresponding wide area network interfaces.

12. The satellite communication method of claim 11, wherein, the SMF network element selects a target CPE device from the CPE devices in the loop, comprising: selecting a CPE device with the highest service level among the CPE devices as the target CPE device; or, selecting a CPE device with the smallest user identification among the CPE devices as the target CPE device; or, selecting a CPE device with the highest user equipment capability among the CPE devices as the target CPE device.

13. The satellite communication method of claim 11, wherein, the loop information comprises topology awareness messages for perceiving user network topology received by the CPE device from at least one other CPE device in the virtual local area network, the method further comprises: the SMF network element determines, according to the topology awareness messages, that the CPE device and the at least one other CPE device form a loop before initiating virtual stacking.

14. The satellite communication method of claim 13, wherein, further comprising: the SMF network element listens to the loop information; in response to not receiving the loop information within a predetermined period, the SMF network element determines that the loop is disconnected; and in response to determining that the loop is disconnected, the SMF network element initiates stack splitting.

15. The satellite communication method of claim 14, wherein, further comprising: in response to receiving the loop information again after not receiving the loop information within the predetermined period, the SMF network element determines that a loop is formed again; and in response to determining that a loop is formed again, the SMF network element initiates virtual stacking.

16. The satellite communication method of claim 11, wherein, the loop information comprises loop formation information directly indicating existence of a loop in the virtual local area network.

17. The satellite communication method of claim 14, wherein, further comprising: In response to receiving loop disconnection information indicating that the loop is disconnected from a CPE device in the loop, the SMF network element initiates stack splitting.

18. The satellite communication method according to claim 14 or 17, characterized by, The stack splitting comprises: The SMF network element instructs the UPF network element to resume establishing a second session with other CPE devices except the target CPE device; or, the SMF network element instructs wide area network interfaces of other CPE devices except the target CPE device to resume forwarding mode; and The SMF network element instructs the UPF network element to copy the second session of the target CPE device to the second session of other CPE devices.

19. The satellite communication method of any one of claims 11-17, wherein, Further comprising: In response to a null port wireless link failure of the target CPE device, the SMF network element sends a session deletion instruction to the UPF network element, so that the UPF network element deletes the session of the target CPE device; The SMF network element instructs the UPF network element to resume establishing a second session with other CPE devices except the target CPE device in the loop; or the SMF network element instructs the wide area network interface of other CPE devices except the target CPE device in the loop to resume forwarding mode; And The SMF network element instructs the UPF network element to copy the second session of the target CPE device into the second session of the other CPE devices.

20. The satellite communication method of claim 11, wherein, The satellite network device comprises a first satellite and a second satellite, the first satellite comprises a first satellite base station, and the second satellite comprises a second satellite base station, the SMF network element selects a target CPE device from each CPE device in the loop, comprising: The SMF network element selects a CPE device corresponding to one of the first satellite base station and the second satellite base station with a shorter feeder link as the target CPE device.

21. The satellite communication method of claim 10, wherein, The satellite network device comprises UPF network elements on multiple satellites, the loop exists in a space network formed by the UPF network elements on the multiple satellites through inter-satellite links, and the virtual stack comprises: The SMF network element binds a first port of the UPF network element in the loop, and instructs each UPF network element to perform stack role election, wherein the stack role election comprises: determining a UPF network element as a master node or a standby node according to a priority rule, and selecting other UPF network elements as slave nodes, wherein the standby node is promoted to a master node in the case that the master node exits the loop; The SMF network element instructs the master node to block a second port in one direction; and In response to the inter-satellite link being disconnected or a CPE device being offline causing the corresponding UPF network element to exit the loop, the SMF network element instructs the master node to resume the blocked second port.

22. The satellite communication method of claim 21, wherein, The priority rule comprises: preferentially selecting a UPF network element corresponding to a satellite base station with a feeder link as a master node or a standby node.

23. A satellite communication method applied to a UPF network element in a virtual local area network, comprising: in response to receiving a virtual stacking command from an SMF network element, the UPF network element virtually stacks a plurality of CPE devices in a loop of a virtual local area network, wherein the virtual local area network comprises a satellite network device and the plurality of CPE devices, and the satellite network device comprises the UPF network element; wherein the method further comprises: a first session is established between the UPF network element and each of the CPE devices for carrying a topology awareness message, the topology awareness message being used for awareness of a user network topology; and the UPF network element broadcasts the topology awareness message to the plurality of CPE devices; the UPF network element virtually stacks a plurality of CPE devices in a loop of a virtual local area network, comprising: the UPF network element virtually stacks a second session after the first session of the plurality of CPE devices, the second session being used for carrying service data.

24. The satellite communication method of claim 23, wherein, each of the CPE devices is communicatively connected with a corresponding inventory LAN device, the inventory LAN device comprising a switch, the CPE device comprising an air-to-space port for communicatively connecting with a corresponding spaceborne base station and a wide area network interface for communicatively connecting with a corresponding switch, and the UPF network element broadcasts the topology awareness message to the plurality of CPE devices through the air-to-space port.

25. The satellite communication method of claim 24, wherein, the UPF network element virtually stacks a second session after the first session of the plurality of CPE devices, comprising: the UPF network element blocks the establishment of a second session between the UPF network element and other CPE devices except for a target CPE device, wherein the target CPE device is a CPE device selected from the plurality of CPE devices by the SMF network element.

26. The satellite communication method of claim 25, wherein, further comprising: in response to receiving a stacking split indication from the SMF network element, the UPF network element performs stacking split, comprising: the UPF network element resumes the establishment of a second session with other CPE devices except for the target CPE device; and the UPF network element replicates the second session of the target CPE device to the second session of other CPE devices.

27. The satellite communication method of claim 25, wherein, further comprising: in response to a failure of an air-to-space port wireless link of the target CPE device, the UPF network element receives a session deletion indication from the SMF network element, and the UPF network element deletes the session of the target CPE device; the UPF network element resumes the establishment of a second session with other CPE devices except for the target CPE device; and the UPF network element replicates the second session of the target CPE device to the second session of other CPE devices.

28. The satellite communication method of any of claims 24-27, wherein, the air-to-space port is a Uu air interface, and the wide area network interface is a WAN port. 29.A satellite communication method applied to an AMF network element in a virtual local area network, comprising: the AMF network element receives a first session request message from a CPE device through a third port; In response to the first session request message, the AMF network element sends a request to establish a first session to a selected SMF network element, so that the SMF network element instructs the CPE device and the UPF network element to establish a first session for carrying a topology awareness packet for awareness of a user network topology, wherein the virtual local area network includes a satellite network device and a plurality of CPE devices, and the satellite network device includes the AMF network element, the SMF network element and the UPF network element, The CPE device is configured to perform the satellite communication method of claim 1.

30. The satellite communication method of claim 29, wherein, Further comprising: The AMF network element receives a registration message from the CPE device through a satellite-borne base station of a satellite, and the registration message includes a first label indicating that the CPE device supports a target service; The AMF network element sends a feedback message to the CPE device through the satellite-borne base station, and the feedback message includes a second label indicating that the satellite supports the target service, so that the CPE device and the satellite establish a virtual local area network.

31. A terminal device comprising: one or more processors; and one or more memories coupled to the one or more processors and storing instructions thereon that, when executed by the one or more processors alone or in combination, cause the terminal device to perform the method of any one of claims 1-9.

32. A network device comprising: one or more processors; and one or more memories coupled to the one or more processors and storing instructions thereon that, when executed by the one or more processors alone or in combination, cause the network device to perform the method of any one of claims 10-30.

33. A non-transitory computer-readable storage medium storing machine-executable instructions that, when executed by one or more processors of a machine, cause the machine to perform the method of any one of claims 1-30.

34. A computer program product comprising machine-executable instructions that, when executed by one or more processors of a machine, cause the machine to perform the method of any one of claims 1-30.

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