Message forwarding method and proxy device

Abstract

The present application provides a message forwarding method and proxy device, which belongs to the field of communication technology. The present application deploys a proxy device between the base station and the core network, and the proxy device implements the NG interface proxy mode. The proxy device uses the link between the local end and the NG interface on the base station and the link between the local end and the NG interface on the core network to forward the control plane data that interacts between the base station and the core network through the NG interface. When this method is used, when the link between the proxy device and the NG interface on the core network is disconnected, since the link between the NG interface on the base station and the proxy device remains normal, the cell can still remain activated, and the user services in the connected state can operate normally and will not be affected. Therefore, when the link is interrupted, the services of users who have connected to the base station remain normal, thereby improving reliability and reducing the reliability requirements for the transmission network.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a message forwarding method and proxy device. Background Art

[0002] The NG interface is the interface between the base station and the core network in the 5G network system. The NG interface is a logical interface. It includes the NG control plane interface and the NG user plane interface. The NG control plane interface is used to transmit control plane messages, such as NAS messages and other signaling messages, between the base station and the core network. The NG user plane interface is used to transmit user plane messages, such as various service data, between the base station and the core network.

[0003] Currently, once the link between the NG interface on the base station and the NG interface on the core network is abnormally interrupted, the cell cannot remain activated, affecting the services of connected users. Summary of the Invention

[0004] The embodiments of the present application provide a message forwarding method and proxy device, which can ensure that the services of users connected to the base station remain normal when the link is interrupted, thereby improving reliability. The technical solution is as follows.

[0005] In a first aspect, a message forwarding method is provided, the method comprising: a proxy device receiving a first control message from a first base station via a first link, the proxy device being deployed between the first base station and a core network element, the first link being a link between an NG interface on the proxy device and an NG interface on the first base station, the first control message including first control plane signaling transmitted based on the NG interface; the proxy device generating a second control message based on the first control message, the second control message including the first control plane signaling; the proxy device sending the second control message to the core network element via a second link, the second link being a link between the NG interface on the proxy device and the NG interface on the core network element.

[0006] The method provided in this embodiment deploys a proxy device between the base station and the core network. The proxy device implements the NG interface proxy mode. The proxy device uses the link between the local end and the NG interface on the base station and the link between the local end and the NG interface on the core network to forward the control plane data exchanged between the base station and the core network via the NG interface. When this method is used, when the link between the proxy device and the NG interface on the core network is disconnected, the link between the NG interface on the base station and the proxy device remains normal, so the cell can still remain activated and the connected user services can operate normally without being affected. Therefore, when the link is interrupted, the services of users connected to the base station remain normal, improving reliability and reducing the reliability requirements of the transmission network.

[0007] Optionally, before the proxy device receives the first control message from the first base station via the first link, the method further includes: receiving, by the proxy device, a first NG setup request from the first base station, the first NG setup request being used to request establishment of the first link; generating, by the proxy device, a first NG setup response, the first NG setup response indicating successful establishment of the first link; and sending, by the proxy device, the first NG setup response to the first base station.

[0008] The proxy device completes the NG interface establishment process with the base station by utilizing the 3GPP standard signaling process, so that the base station is unaware of the existence of the proxy device and realizes the proxy function of the NG interface control plane.

[0009] Optionally, before the proxy device sends the second control message to the core network network element through the second link, the method also includes: the proxy device generates a second NG establishment request, the second NG establishment request is used to request establishment of the second link; the proxy device sends the second NG establishment request to the core network network element; the proxy device receives a second NG establishment response from the core network network element, the second NG establishment response indicating that the second link is successfully established.

[0010] The proxy device completes the NG interface establishment process with the core network element by utilizing the 3GPP standard signaling process, so that the core network element is unaware of the existence of the proxy device and realizes the proxy function of the NG interface control plane.

[0011] Optionally, the method also includes: the proxy device receives a third control message from the core network network element through the second link, the third control message including second control plane signaling transmitted based on the NG interface; the proxy device generates a fourth control message based on the third control message, the fourth control message including the second control plane signaling; the proxy device sends the fourth control message to the first base station through the first link.

[0012] Through the above implementation, the proxy device not only implements the control plane proxy of the NG interface in the direction from the base station to the core network, but also implements the control plane proxy of the NG interface in the direction from the core network to the base station.

[0013] Optionally, the third control message includes a non-access stratum (NAS) message. Before the proxy device sends the fourth control message to the first base station through the first link, the method also includes: the proxy device determines the first base station based on the NAS message and a first correspondence, where the first correspondence is a correspondence between the NAS message and the first base station.

[0014] Through the above implementation method, the distribution of NAS messages is realized. That is, in a scenario where multiple base stations are deployed, when the core network sends a NAS message, the NAS message can be distributed to the corresponding base station, and then the NAS message is distributed to the corresponding terminal through the base station.

[0015] Optionally, the method also includes: the proxy device receives a switching message from the second base station, the switching message instructing the base station accessed by the first terminal to switch from the first base station to the second base station, and the first terminal is the initiator or destination of the NAS message in the first control message; the proxy device updates the first correspondence to a second correspondence, and the second correspondence is the correspondence between the NAS message and the second base station.

[0016] Through the above implementation, when the base station to which the terminal accesses switches, the correspondence between the NAS message and the base station is refreshed, thereby switching the forwarding path of the NAS message, ensuring that the NAS message of the core network element can still be delivered to the terminal after the cross-site handover.

[0017] Optionally, the method also includes: the proxy device receives a first business message from the first base station through the first link; if the type of business data in the first business message is industry user data, the proxy device forwards the first business message to the local area network where the industry user is located; if the type of business data in the first business message is personal user data, the proxy device forwards the first business message to the core network network element through the second link.

[0018] Through the above method, local diversion of the NG interface data plane is achieved, ensuring that the business data of industry users does not leave the local area network, thereby meeting the industry users' requirements for the security and privacy of business data, and at the same time reducing the forwarding delay of industry users' business data.

[0019] Optionally, after the proxy device receives the first service message from the first base station through the first link, the method further includes: the proxy device identifying the type of service data in the first service message based on the service identifier carried by the first service message, and the service identifier includes a public land mobile network (Public Land Mobile Network, PLMN) identifier, a network slice identifier, a data network name (data network name, DNN) or at least one item in a five-tuple.

[0020] Through the above method, multiple diversion strategies such as PLMN identification, slice identification, DNN, and quintuple are supported, thereby improving the flexibility of local diversion.

[0021] Optionally, the proxy device forwards the first service message to the core network element through the second link, including: the proxy device adopts a transparent transmission manner to forward the first service message to the core network element through the second link.

[0022] Optionally, the first service message includes a General Packet Radio Service Tunneling Protocol for the user plane (GTP-U or GTPU) message header of the user plane, and the proxy device forwards the first service message to the local area network where the industry user is located, including: the proxy device strips the GTPU message header of the first service message to obtain a second service message; the proxy device sends the second service message to the local area network where the industry user is located.

[0023] Optionally, the first control message is received by the first base station from a third base station, and the third base station is a slave base station of the first base station. The proxy device generates a second control message based on the first control message, including: the proxy device replaces the source Internet Protocol (IP) address of the first control message from the IP address of the third base station to the IP address of the first base station.

[0024] Through the above implementation method, by replacing the source IP address from the IP address of the slave base station to the IP address of the master base station, the core network does not perceive the slave base station, thereby avoiding the problem of the core network sensing multiple base stations, resulting in the need for interactive NG interface control plane signaling between the base station and the core network in the cross-base station switching scenario.

[0025] Optionally, the first control message is received by the first base station from a third base station, where the third base station is a slave base station of the first base station. The first control message includes a user identifier allocated by the third base station to the first terminal. The proxy device generates a second control message based on the first control message, including:

[0026] The proxy device replaces the user identifier carried in the first control message with the user identifier allocated to the first terminal by the first base station.

[0027] With the above implementation, since the user identifiers in the control messages received by the core network from each base station are all user identifiers allocated by the master base station, duplication of user identifiers of the same user in control messages from different base stations is avoided, thereby preventing user identifier conflicts.

[0028] Optionally, before the proxy device receives the first control message from the first base station through the first link, the method also includes: the proxy device obtains the IP address of the core network network element and the IP address of the proxy device from the customer premises equipment (CPE), the CPE is deployed between the proxy device and the core network element, and the CPE operates in bridging mode; the proxy device sends the IP address of the core network element and the IP address of the proxy device to the first base station.

[0029] Through the above implementation, wireless self-backhaul is realized, so that the proxy device can be activated without configuration, simplifying the activation process.

[0030] Optionally, the proxy device obtains the IP address of the core network network element and the IP address of the proxy device from the CPE, including: the proxy device generates a dynamic host configuration protocol (DHCP) request message; the proxy device receives a DHCP response message from the CPE, and the DHCP response message includes the IP address of the core network network element and the IP address of the proxy device.

[0031] In a second aspect, a proxy device is provided, the proxy device comprising:

[0032] a receiving unit, configured to receive a first control message from a first base station through a first link, where the proxy device is deployed between the first base station and a core network element, the first link being a link between an NG interface on the proxy device and an NG interface on the first base station, and the first control message including first control plane signaling transmitted based on the NG interface;

[0033] a processing unit, configured to generate a second control message based on the first control message, where the second control message includes the first control plane signaling;

[0034] The sending unit is configured to send the second control message to the core network element through a second link, where the second link is a link between the NG interface on the proxy device and the NG interface on the core network element.

[0035] Optionally, the receiving unit is further configured to receive a first NG establishment request from the first base station, where the first NG establishment request is used to request establishment of the first link;

[0036] The processing unit is further configured to generate a first NG establishment response, where the first NG establishment response indicates that the first link is successfully established;

[0037] The sending unit is further configured to send the first NG establishment response to the first base station.

[0038] Optionally, the processing unit is further configured to generate a second NG establishment request, where the second NG establishment request is used to request establishment of the second link;

[0039] The sending unit is further configured to send the second NG establishment request to the core network element;

[0040] The receiving unit is further configured to receive a second NG establishment response from the core network element, where the second NG establishment response indicates that the second link is successfully established.

[0041] Optionally, the receiving unit is further configured to receive a third control message from the core network element through the second link, where the third control message includes second control plane signaling transmitted based on the NG interface;

[0042] The processing unit is further configured to generate a fourth control message based on the third control message, where the fourth control message includes the second control plane signaling;

[0043] The sending unit is further configured to send the fourth control message to the first base station through the first link.

[0044] Optionally, the third control message includes a non-access stratum NAS message, and the processing unit is further used to determine the first base station based on the NAS message and a first corresponding relationship, where the first corresponding relationship is a corresponding relationship between the NAS message and the first base station.

[0045] Optionally, the receiving unit is further configured to receive a handover message from the second base station, where the handover message instructs the base station accessed by the first terminal to be switched from the first base station to the second base station, and the first terminal is the initiator or destination of the NAS message in the first control message;

[0046] The processing unit is further configured to update the first correspondence to a second correspondence, where the second correspondence is a correspondence between the NAS message and the second base station.

[0047] Optionally, the receiving unit is also used to receive a first business message from the first base station through the first link; the sending unit is also used to forward the first business message to the local area network where the industry user is located if the type of business data in the first business message is industry user data; if the type of business data in the first business message is personal user data, forward the first business message to the core network network element through the second link.

[0048] Optionally, the processing unit is also used to identify the type of business data in the first business message based on the business identifier carried by the first business message, and the business identifier includes the identifier of the public land mobile communication network PLMN, the identifier of the network slice, the data network name DNN or at least one of the five-tuple.

[0049] Optionally, the sending unit is configured to forward the first service message to the core network element via the second link in a transparent transmission manner.

[0050] Optionally, the first service message includes a General Packet Radio Service Tunneling Protocol GTPU message header on the user plane, and the sending unit is used to strip the GTPU message header of the first service message to obtain a second service message; and send the second service message to the local area network where the industry user is located.

[0051] Optionally, the first control message is received by the first base station from a third base station, and the third base station is a slave base station of the first base station. The processing unit is used to replace the source Internet Protocol IP address of the first control message from the IP address of the third base station to the IP address of the first base station.

[0052] Optionally, the first control message is received by the first base station from a third base station, and the third base station is a slave base station of the first base station. The first control message includes a user identifier assigned by the third base station to the first terminal, and the processing unit is used to replace the user identifier carried by the first control message with the user identifier assigned by the first base station to the first terminal.

[0053] Optionally, the receiving unit is also used to obtain the IP address of the core network network element and the IP address of the proxy device from the customer premises equipment CPE, the CPE is deployed between the proxy device and the core network element, and the CPE operates in bridging mode; the sending unit is also used to send the IP address of the core network network element and the IP address of the proxy device to the first base station.

[0054] Optionally, the processing unit is used to generate a Dynamic Host Configuration Protocol DHCP request message; the receiving unit is used to receive a DHCP response message from the CPE, and the DHCP response message includes the IP address of the core network element and the IP address of the proxy device.

[0055] In some embodiments, the units in the proxy device are implemented by software, and the units in the proxy device are program modules. In other embodiments, the units in the proxy device are implemented by hardware or firmware. The specific details of the proxy device provided in the second aspect can be found in the first aspect or any of the optional embodiments of the first aspect, and are not further described here.

[0056] In a third aspect, a proxy device is provided. The proxy device includes a processor coupled to a memory, the memory storing at least one computer program instruction, the at least one computer program instruction being loaded and executed by the processor to cause the proxy device to implement the method provided in the first aspect or any optional embodiment of the first aspect. Specific details of the proxy device provided in the third aspect can be found in the first aspect or any optional embodiment of the first aspect, and are not further described here.

[0057] In a fourth aspect, a computer-readable storage medium is provided, which stores at least one instruction. When the instruction is executed on a computer, the computer executes the method provided by the first aspect or any optional embodiment of the first aspect.

[0058] In a fifth aspect, a computer program product is provided, which includes one or more computer program instructions. When the computer program instructions are loaded and run by a computer, the computer executes the method provided by the first aspect or any optional method of the first aspect.

[0059] In a sixth aspect, a chip is provided, comprising a memory and a processor, wherein the memory is used to store computer instructions, and the processor is used to call and run the computer instructions from the memory to execute the method in the above-mentioned first aspect and any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1This is a flow chart of a message forwarding method provided by an embodiment of the present application;

[0061] Figure 2 This is a schematic diagram of an application scenario provided by an embodiment of the present application;

[0062] Figure 3 This is a signaling flow chart provided by an embodiment of the present application;

[0063] Figure 4 This is a schematic diagram of a link disconnection scenario provided by an embodiment of the present application;

[0064] Figure 5 This is a schematic diagram of a terminal state switching provided by an embodiment of the present application;

[0065] Figure 6 This is a schematic diagram of a network deployment scenario provided by an embodiment of the present application;

[0066] Figure 7 This is a signaling flow chart provided by an embodiment of the present application;

[0067] Figure 8 This is a schematic diagram of a network deployment scenario provided by an embodiment of the present application;

[0068] Figure 9 7 is a schematic diagram of the structure of a proxy device 700 provided in an embodiment of the present application;

[0069] Figure 10 8 is a schematic diagram of the structure of a proxy device 800 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the drawings.

[0071] The technology described in the embodiments of the present application can be used in various wireless communication systems, such as 4G systems such as LTE (Long Term Evolution) systems, new radio (NR, etc.) 5G (the fifth generation) systems, etc., without limitation.

[0072] The following is an explanation of some terminology concepts involved in the embodiments of this application.

[0073] (1) Proxy device

[0074] Proxy devices are used to forward packets related to the NG interface. They are deployed between base stations and core network elements. For example, in a 5G network, they are deployed between the gNodeB and the 5GC. The proxy devices establish links with the NG interface on the base station and the NG interface on the core network element.

[0075] The proxy device itself acts as both a client and a server for the NG control plane. From the base station's perspective, the proxy device receives request messages sent by the base station via the NG interface and processes them for it, thus implementing the NG control plane server. From the core network's perspective, the proxy device sends request messages to the core network's NG interface, requesting the core network to process them, thus implementing the NG control plane client.

[0076] Proxy devices can take many forms. Optionally, the proxy device can be a newly added module within a base station. For example, the proxy device can be a newly added computing board within the base station. For example, the proxy device can be an embedded board within the base station BBU chassis. Alternatively, the proxy device can be a standalone device, such as a dedicated or general-purpose network device like a router, switch, or firewall.

[0077] (2) Base Station

[0078] A base station is also called an access network (AN) device, and in specific applications, it can also be called a radio access network (RAN). Base stations include but are not limited to NBs, eNBs, gNBs, etc.

[0079] (3)gNodeB

[0080] gNodeB is a base station in the 5G network, abbreviated as gNB.

[0081] (4) Core network (CN)

[0082] As a bearer network, the core network provides an interface to the DN, offering terminal communication connectivity, authentication, management, policy control, and data service bearering. Core network elements include access and mobility management elements, session management elements, authentication server elements, policy control nodes, application function elements, and user plane nodes. These elements are described below.

[0083] The Access and Mobility Management Function (AMF) is a control plane element provided by the operator. It is responsible for access control and mobility management for terminals accessing the operator's network. It serves as the termination point for NAS signaling and processes network signaling.

[0084] Security Anchor Function (SEAF), SEAF is connected to AMF and serves as a node for security authentication functions. In specific implementations, AMF and SEAF can be deployed together in a physical location, or they can be set up independently. In addition, in possible implementations, the functions of AMF and SEAF can be separated and deployed in different network elements, or the functions of AMF and SEAF can be set up in the same network element (for example, AMF has the function of SEAF).

[0085] Session Management Function (SMF), a control plane network element provided by the operator, is responsible for managing the session of terminal data packets.

[0086] Authentication server function (AUSF) is a control plane element provided by the operator for terminal authentication. AUSF can be deployed as an independent logical functional entity or integrated into devices such as AMF / SMF.

[0087] The Unified Data Manager (UDM), a control plane element provided by the operator, is responsible for storing the operator's network subscriber persistent identifier (SUPI), registration information, credentials, and contract data. This data is used for terminal authentication and authorization to access the operator's network.

[0088] Application Function (AF) is used to store business security requirements and provide information for policy decisions.

[0089] A User Plane Function (UPF) is a network element that can be a gateway, server, controller, or user plane function element. The UPF can be located inside or outside the carrier network. The UPF is a user plane element provided by the carrier and serves as the gateway for communication between the carrier network and the DN.

[0090] Policy control function (PCF): PCF is deployed with the policy control function. The policy control function is to complete the negotiation of the user plane protection mechanism according to security requirements and determine the function of the user plane protection mechanism in the network.

[0091] (5) Idle state, inactive state and connected state.

[0092] Idle, inactive, and connected are the three RRC states of terminals in the 5G system. In the inactive state, the terminal's user plane connection is released, but the control plane connection remains. If data needs to be sent, the terminal's state is transitioned to the connected state through paging. The advantage of the inactive state is that when the terminal has data to transmit, it can quickly enter the connected state without having to establish a signaling bearer with the core network.

[0093] (6) 5G core network (5GC)

[0094] 5GC is the core network of the 5G system. The network elements in 5GC include AMF, SMF, and UPF.

[0095] (7) Control message

[0096] Control messages are messages exchanged on the control plane of a network system. They contain various signalings, such as those used to control the establishment, maintenance, and release of call flows.

[0097] (8) Business messages

[0098] Business messages refer to messages exchanged on the user plane (also known as the data plane) of a network system. Business messages contain user business data, such as enterprise production data, voice, text messages, and emails.

[0099] (9) Wireless private network

[0100] A wireless private network, also known as a wireless private network, is a dedicated network that provides network signal coverage within a specific area, thereby providing communication services to specific users. The key difference between a wireless private network and a public network is that the public network serves the general public, while a private network serves specific users. A typical application scenario is deploying a private network within an enterprise campus to provide dedicated communication services to enterprise users' terminals and servers. Compared to the public network, private networks offer higher performance, higher reliability, and improved security, and can be customized to meet user needs. They are used in military, public security, railway, port, energy, manufacturing, and other scenarios.

[0101] (10) 5G private network

[0102] A 5G private network is a dedicated 5G network serving specific users. One deployment method involves an enterprise building a 5G network based on private 5G spectrum. This approach completely isolates the private network from the public network, providing enhanced privacy and security, but also increasing costs. Another deployment method involves building a 5G private network based on operator-licensed 5G frequency bands (i.e., licensed spectrum).

[0103] (11) Local Traffic Offload

[0104] The "local" in local offload refers to the local area network (LAN) where the industry user resides. Local offload means that after the industry user's terminal transmits service data to a base station deployed in the LAN, the base station forwards part or all of the service data to the service server deployed in the LAN, rather than first forwarding the service data through the transmission network to the core network and then forwarding it back to the service server deployed in the LAN. This avoids traffic detours, reduces the transmission load and cost of the backhaul network, and ensures high bandwidth and low latency for terminals within the LAN to access servers in the local network, while also ensuring the security of local data.

[0105] Taking the enterprise campus network scenario as an example, automated production within the campus has high requirements for low latency. In traditional network architectures, when a campus terminal generates service data, the data is forwarded from the campus terminal to the campus base station to the core network to the internet and then to the campus service server. This data needs to be transmitted through the wireless access network, bearer network, and core network, resulting in high latency. Therefore, shortening the transmission path is necessary to reduce latency. Furthermore, much of the service data generated by campus terminals involves critical enterprise business data, such as machine vision, remote control, and AGVs (Automated Guided Vehicles). This data requires high security and confidentiality, ensuring that business data does not leave the campus. Therefore, the campus base station performs local traffic diversion, offloading local data flows to the campus server. This meets both of these requirements, ensuring low latency and the need for data to leave the campus. This simplifies networking and reduces the cost of building a virtual private network for enterprises.

[0106] (12) Public Land Mobile Network (PLMN)

[0107] A PLMN is a network established and operated by the government or an operator approved by it to provide land mobile communications services to the public. The PLMN identifier consists of two parts: the MCC (country code) and the MNC (mobile network code). The MNC in the PLMN identifier varies between operators.

[0108] (13) Data network name (DNN)

[0109] DNN is used to identify the external network to which the user is connected.

[0110] (14)Return

[0111] Backhaul refers to the data transmission process from the base station to the core network. Backhaul technology is mainly implemented in two ways: one is wired backhaul, for example, the base station transmits data to the core network via optical fiber. The other is wireless backhaul, in which the base station transmits data to the core network via wireless signals.

[0112] (15) Base station self-opening

[0113] Automatic base station commissioning refers to the automatic configuration of parameters during the base station commissioning process, so that the base station can automatically complete the commissioning process.

[0114] (16) Network Slicing

[0115] Network slicing, also known as network fragmentation, refers to dividing a physical network into multiple virtual networks. Each virtual network meets the needs of different application scenarios. Different virtual networks are logically independent and do not affect each other.

[0116] (17) Stream Control Transmission Protocol (SCTP)

[0117] SCTP is a reliable, universal transport layer protocol used on IP networks. SCTP is a connection-oriented stream transport protocol that provides stable, ordered data delivery between two endpoints. SCTP resides at the same level in the IP protocol stack as TCP and UDP. In the 4G core network EPC, SCTP is used at the transport layer of the S1 interface between the eNB and the MME. 5G continues the 4G philosophy and also uses SCTP at the transport layer of the N2 interface between the gNB and the AMF.

[0118] (18) Non-Access-Stratum (NAS)

[0119] NAS is the control plane protocol between the terminal and the AMF. Its functions include supporting general procedures for terminal mobility, such as authentication, authorization, general terminal configuration update, and security control mode procedures; supporting session management procedures to establish and maintain data connections between the terminal and the data network; and supporting NAS transport procedures to provide the transmission of payloads such as SMS, LPP, terminal policy containers, SOR transparent containers, and terminal parameter update information.

[0120] (19) GPRS Tunneling Protocol (GTP)

[0121] GTP is a set of high-level protocols based on IP, layered on top of protocols such as TCP / IP or UDP / IP. GTP protocols are divided into the GPRS Tunneling Protocol-Control Plane (GTP-C), the GPRS Tunneling Protocol for the User Plane (GTP-U or GTPU), and GTP'. GTP-C is a signaling control protocol used to transmit control information between two nodes, such as establishing a public transport protocol (PDP) and adjusting quality of service (QoS) parameters. GTP-U is used to transmit user-plane data between two nodes. GTP' is a billing-related protocol.

[0122] (20) Customer Premise Equipment (CPE)

[0123] CPE is a mobile signal access device that receives mobile signals and forwards them as wireless signals. It converts high-speed 4G / 5G signals into wireless signals and can support a large number of mobile terminals accessing the internet simultaneously.

[0124] (21) Transmission Sequence Number (TSN)

[0125] SCTP uses the TSN mechanism to confirm data transmission. One of the two endpoints in SCTP communication sequentially assigns a 32-bit sequence number based on the initial TSN to each data block sent by the other end, so that the other end can confirm when it receives it.

[0126] (22) Stream Sequence Number (SSN)

[0127] SCTP sequentially assigns a 16-bit SSN to each data block sent by the local end in this stream to ensure sequential delivery within the stream.

[0128] The following is an explanation of some interfaces involved in the embodiments of this application.

[0129] The NG interface refers to the interface between the base station and the core network. The N1 interface is the interface used for interaction between the terminal and the AMF. The communication protocols corresponding to the N1 interface include the NAS protocol, SMS protocol, etc. The N2 interface is the interface used when the AN interacts with the AMF. The communication protocols corresponding to the N2 interface include the NG application layer protocol (NG Application Protocol, NG-AP protocol, the application layer protocol between 5G-AN and AMF). The N4 interface is the interface used when the UPF interacts with the SMF. The communication protocols corresponding to the N4 interface include the PFCP protocol. Table 1 below shows the interface name, endpoint network element, protocol and transmission characteristics of each interface.

[0130] Table 1

[0131] Interface Name Endpoint network element protocol Transmission characteristics NG interface RAN 5GC Interface between base station and core network N2 (R)AN-AMF NG-AP Control Surface N4 SMF-UPF PFCP, GTP-U Control plane + user plane N3 (R)AN-UPF GTP-U User plane

[0132] Figure 1 This is a flowchart of a message forwarding method provided in an embodiment of the present application.

[0133] Figure 1 The illustrated method involves the link between a base station and a proxy device, and the link between the proxy device and a core network element. To distinguish between the different links, the term "first link" is used to describe the link between the NG interface on the proxy device and the NG interface on the first base station, and the term "second link" is used to describe the link between the NG interface on the proxy device and the NG interface on the core network element.

[0134] Figure 1 The method shown involves a scenario where multiple base stations are deployed. In order to distinguish different base stations, "first base station" and "second base station" are used to distinguish and describe different base stations.

[0135] Figure 1 The method described involves processing messages within the proxy device. The messages sent by the proxy device may differ from the original messages received by the proxy device. To distinguish between different messages, the term "first control message" is used to describe control messages received by the proxy device, and the term "second control message" is used to describe control messages sent by the proxy device.

[0136] Figure 1 The illustrated method includes the following S101 to S105 .

[0137] S101. A first base station sends a first control message through a first link.

[0138] The first control message includes first control plane signaling transmitted over the NG interface. Specifically, the first control message includes a message header and a payload portion, where the payload portion includes the first control plane signaling. The message header in the first control message is a message header of the transmission protocol between the base station and the core network, for example, an SCTP message header.

[0139] The first control plane signaling is signaling to be sent to a core network element. For example, the first control plane signaling indicates an operation that the core network element needs to perform.

[0140] Optionally, the first control plane signaling is signaling generated by the base station. For example, the first control plane signaling is signaling generated by the first base station, or signaling generated by another base station and forwarded by the first base station. Optionally, the first control plane signaling is signaling generated by the terminal. For example, the first control plane signaling is signaling generated by the terminal served by the first base station.

[0141] Optionally, the first control message is a request message, or the first control message is a response message.

[0142] S102: The proxy device receives a first control message from the first base station through a first link.

[0143] S103: The proxy device generates a second control message based on the first control message.

[0144] The second control message includes the first control plane signaling. That is, compared with the first control message, the content of the control plane signaling in the second control message remains unchanged.

[0145] Illustratively, after receiving the first control message, the proxy device modifies the message header in the first control message and keeps the first control plane signaling in the first control message unchanged, thereby obtaining the second control message.

[0146] Optionally, the proxy device modifies the source IP address in the message header of the first control message to obtain a second control message. For example, if the source IP address in the first control message is the IP address of the base station, the proxy device modifies the source IP address in the first control message to its own IP address to obtain a second control message. The source IP address in the second control message is the IP address of the proxy device.

[0147] Optionally, the proxy device modifies the transmission sequence number and the stream sequence number in the message header of the first control message to obtain the second control message.

[0148] In a possible implementation, the proxy device modifies the transmission sequence number and flow sequence number in the first control message according to the transmission sequence numbers and flow sequence numbers of messages exchanged between the proxy device and the core network element in a historical time period.

[0149] The transmission sequence number is, for example, the TSN in SCTP, which indicates the logical order of different messages in the same data stream so that the receiving end can detect whether packet loss has occurred. The stream sequence number is, for example, the SSN in SCTP.

[0150] Taking the process of modifying the transmission sequence number as an example, in an exemplary embodiment, after the base station and the proxy device establish a connection based on a transport layer protocol (such as SCTP), the base station sequentially assigns a transmission sequence number to each message sent to the proxy device via the connection. After the proxy device and the core network element establish a logical channel for the transport layer protocol (such as SCTP), the proxy device sequentially assigns a transmission sequence number to each message sent to the core network element via the logical channel. The first control message mentioned above includes a transmission sequence number assigned by the first base station. The transmission sequence number in the first control message indicates the order between the first control message and messages previously sent by the first base station to the proxy device. The proxy device modifies the transmission sequence number in the first control message to the transmission sequence number assigned by the proxy device, so that the transmission sequence number in the second control message indicates the order between the second control message and messages previously sent by the proxy device to the core network element. The process of modifying the flow sequence number is basically the same as the process of modifying the transmission sequence number.

[0151] Optionally, this embodiment is applied in a scenario involving multiple base stations, where the multiple base stations operate in a master-slave mode, with one base station serving as the master base station and the other base stations serving as slave base stations. Control messages sent by each slave base station to the core network are aggregated to the master base station. The master base station sends control messages that need to be sent locally to the core network, as well as control messages that need to be sent by each slave base station to the core network, to a proxy device. The proxy device then forwards the control messages from the master base station and each slave base station to the core network.

[0152] Optionally, the proxy device replaces the source IP address in the control message from the base station from the IP address of the slave base station to the IP address of the master base station, and then sends the control message with the replaced source IP to the core network. Then, from the perspective of the core network, since the source IP address of the control message of each base station received by the core network is the IP address of the master base station, the source device of the control message perceived by the core network is the master base station, and the source device of the control message is not perceived by each slave base station. Therefore, it can avoid the problem that the core network perceives multiple base stations, resulting in the need for interactive NG interface control plane signaling between the base station and the core network in the cross-base station handover scenario. Optionally, the replacement of the IP address is applied in the bearer establishment phase. For example, the control message is specifically a bearer establishment request message, which is used to request the establishment of a wireless bearer between the core network and the terminal connected to the slave base station.

[0153] For example, the first base station is a master base station, and its slave base station includes a third base station. The first control message is sent from the third base station to the first base station. After receiving the first control message from the third base station, the first base station sends the first control message to the proxy device. The proxy device replaces the source IP address of the first control message from the IP address of the third base station to the IP address of the first base station, thereby generating the second control message. The source IP address of the second control message is the IP address of the first base station.

[0154] The above description of the proxy device replacing the IP address of the slave base station is merely exemplary. In other embodiments, rather than the proxy device replacing the IP address of the slave base station, the master base station replaces the IP address of the slave base station. Specifically, after the master base station receives a control message from the slave base station, it replaces the source IP address in the control message with the IP address of the master base station, sends the control message with the replaced IP address to the proxy device, and the proxy device forwards the control message with the replaced IP address to the core network.

[0155] Optionally, the proxy device replaces the user identifier in the control message from each slave base station with the user identifier uniformly assigned by the master base station to the corresponding user, and then sends the control message with the replaced user identifier to the core network. In this case, since the user identifier in the control message received by the core network from each base station is the user identifier assigned by the master base station, duplication of the user identifier of the same user in control messages from different base stations is avoided, thereby preventing user identifier conflicts.

[0156] For example, the first base station is a master base station, and its slave base station includes a third base station. The first control message is sent from the third base station to the first base station. The first control message includes a user identifier assigned by the third base station to the first terminal. After receiving the first control message from the third base station, the first base station sends the first control message to the proxy device. The proxy device replaces the user identifier carried in the first control message with the user identifier assigned by the first base station to the first terminal, thereby generating the second control message. The user identifier carried in the second control message is the user identifier assigned by the first base station to the first terminal.

[0157] There are multiple ways for the proxy device to obtain the user identifier assigned by the first base station. For example, the proxy device negotiates with the core network element to obtain the user identifier assigned by the first base station. In another example, after the first base station assigns user identifiers to each terminal, it sends the user identifiers to the proxy device.

[0158] S104: The proxy device sends a second control message to the core network element through the second link.

[0159] S105. The core network element receives a second control message through a second link.

[0160] The method provided in this embodiment deploys a proxy device between the base station and the core network. The proxy device implements the NG interface proxy mode. The proxy device uses the link between the local end and the NG interface on the base station and the link between the local end and the NG interface on the core network to forward the control plane data exchanged between the base station and the core network through the NG interface. When this method is used, when the link between the proxy device and the NG interface on the core network is disconnected, the link between the NG interface on the base station and the proxy device remains normal, so that the cell can still remain activated and the normal operation of connected user services will not be affected. Therefore, it is ensured that users who have been connected to the base station when the link is interrupted remain normal, thereby improving reliability and reducing the reliability requirements of the transmission network.

[0161] In some embodiments, the proxy device and the base station establish the first link using a signaling process involving an NG setup request and an NG setup response. Specifically, the process of establishing the first link between the proxy device and the base station includes: the first base station sends a first NG setup request, where the first NG setup request is used to request establishment of the first link; the proxy device receives the first NG setup request from the first base station; the proxy device generates a first NG setup response in response to the first NG setup request, where the first NG setup response indicates successful establishment of the first link; and the proxy device sends the first NG setup response to the first base station.

[0162] In some embodiments, the proxy device and the core network element establish the second link by using a signaling process involving an NG setup request and an NG setup response. Specifically, the process of establishing the second link between the proxy device and the core network element includes: the proxy device generates a second NG setup request, the second NG setup request being used to request establishment of the second link; the proxy device sends the second NG setup request to the core network element; the core network element generates an NG setup response in response to the second NG setup request, the second NG setup response indicating successful establishment of the second link; the core network element sends the second NG setup response to the proxy device; and the proxy device receives the second NG setup response from the core network element.

[0163] For details on NG setup request and NG setup response, please refer to the 3GPP standard.

[0164] Optionally, the proxy device first interacts with the core network element to establish the second link, and then interacts with the base station to establish the first link. Alternatively, the proxy device first interacts with the base station to establish the first link, and then interacts with the core network element to establish the second link. This embodiment does not limit the timing of the process of establishing the first link and the process of establishing the second link.

[0165] In some embodiments, the proxy device not only proxies the NG interface from the base station to the core network, but also proxies the NG interface from the core network to the base station. For example, the core network element sends a third control message via the second link. The proxy device receives the third control message via the second link. The proxy device generates a fourth control message based on the third control message; the proxy device sends the fourth control message to the first base station via the first link. The first base station receives the fourth control message via the first link.

[0166] The third control message includes second control plane signaling transmitted over the NG interface. Optionally, the second control plane signaling is signaling to be sent to the first base station. For example, the second control plane signaling indicates an operation to be performed by the first base station. Optionally, the second control plane signaling is signaling generated by a core network element.

[0167] The fourth control message includes the second control plane signaling. That is, compared with the third control message, the content of the control plane signaling in the fourth control message remains unchanged.

[0168] Illustratively, after receiving the third control message, the proxy device modifies the message header in the third control message and keeps the second control plane signaling in the third control message unchanged, thereby obtaining a fourth control message.

[0169] Optionally, the proxy device modifies the source IP address in the header of the third control message to obtain a fourth control message. For example, if the source IP address in the third control message is the IP address of a core network element, the proxy device modifies the source IP address in the third control message to its own IP address to obtain a fourth control message. The source IP address in the fourth control message is the IP address of the proxy device.

[0170] Optionally, the second control message sent to the core network element is a request message, and the first control plane signaling in the second control message is signaling indicating the request. The third control message subsequently sent by the core network element is a response message to the second control message, and the second control plane signaling in the third control message is an acknowledgment signaling to the first control plane signaling.

[0171] In one possible implementation, the proxy device modifies the transmission sequence number and flow sequence number in the third control message based on the transmission sequence number and flow sequence number of the message exchanged with the base station in the historical time period. Taking the process of modifying the transmission sequence number as an example, for example, the third control message includes the transmission sequence number assigned by the core network network element, and the transmission sequence number in the third control message indicates the sequence between the third control message and the message historically sent by the core network network element to the proxy device. The proxy device modifies the transmission sequence number in the third control message to the transmission sequence number assigned by the proxy device, so that the transmission sequence number in the fourth control message indicates the sequence between the fourth control message and the message historically sent by the proxy device to the base station. The process of modifying the flow sequence number is basically the same as the process of modifying the transmission sequence number.

[0172] In some embodiments, when there are multiple base stations, after a proxy device receives a NAS message sent by a core network element, the proxy device uses the correspondence between NAS messages and base stations to forward the NAS message to the corresponding base station. For example, the third control message generated by the core network element includes a NAS message destined for a first terminal. After receiving the third control message, the proxy device determines the first base station based on the NAS message and the first correspondence, and sends a fourth control message including the NAS message to the first base station. The first correspondence is the correspondence between the NAS message and the first base station. After receiving the fourth control message including the NAS message, the first base station forwards the NAS message to the first terminal.

[0173] In some embodiments, in the scenario of cross-site handover, the proxy device updates the correspondence between the NAS message and the base station. For example, the first terminal was originally located in the cell served by the first base station, and the first terminal accessed the above-mentioned first base station. The NAS message initiated by the first terminal is forwarded to the core network via the first base station, and the NAS message sent by the core network to the first terminal is forwarded to the first terminal via the first base station. Afterwards, the first terminal moves from the cell served by the first base station to the cell served by the second base station, and the first terminal re-accesses the second base station. Afterwards, the second base station generates a handover message and sends a handover message, and the handover message instructs the base station accessed by the first terminal to switch to the second base station. The proxy device receives the handover message from the second base station. Based on the handover message, the proxy device updates the first correspondence to the second correspondence, and the second correspondence is the correspondence between the NAS message and the second base station.

[0174] Optionally, the proxy device also implements local data plane offload on the NG interface. Specifically, the proxy device forwards service data from industry users to a service server in the local area network (LAN) where the industry users are located, and forwards service data from individual users to the core network. Industry users include, but are not limited to, enterprises, campuses, military, public security, railways, and ports. Service data from individual users includes, for example, data for phone calls, video calls, and internet access. Taking the process of forwarding a first service message as an example, after receiving a first service message from a first base station via a first link, the proxy device identifies the type of service data in the first service message. If the service data in the first service message is industry user data, the proxy device forwards the first service message to the local area network (LAN) where the industry user is located. Subsequently, a router deployed at the LAN boundary receives the first service message and forwards it to a service server in the LAN. The service server performs service processing based on the first service message. If the service data in the first service message is individual user data, the proxy device forwards the first service message to a core network element via a second link. The core network element receives the first service message, processes it, and then forwards it to the Internet.

[0175] Optionally, the proxy device distinguishes between service data that requires local diversion and service data that does not require local diversion based on the service identifier. The service identifier includes but is not limited to the identifier of the PLMN to which the terminal belongs, the identifier of the network slice (slice ID), the DNN, or a five-tuple (such as a source address or a destination address). Taking the process of processing the first service message as an example, the proxy device identifies the type of service data in the first service message based on the service identifier carried by the first service message.

[0176] Optionally, if the service data in the first service message is personal user data, the proxy device does not modify the service message, but instead transparently transmits the first service message to the core network element via the second link. If the service data in the first service message is industry user data, the proxy device is responsible for processing the GTPU header. Taking the process of processing the first service message as an example, for example, after the proxy device receives the first service message from the first base station, the proxy device strips the GTPU header from the first service message to obtain a second service message; the proxy device then sends the second service message to the local area network where the industry user is located.

[0177] In some embodiments, a proxy device can automatically obtain the parameters required for base station deployment, eliminating the workload associated with manual parameter configuration. Specifically, a CPE is deployed between the proxy device and a core network element. The CPE operates in bridging mode. The proxy device obtains the IP address of the core network element and the proxy device from the CPE. The proxy device sends the IP address of the core network element and the proxy device to the first base station.

[0178] In some embodiments, a proxy device obtains an IP address through a DHCP process. Specifically, the proxy device acts as a DHCP client, and the CPE acts as a DHCP server. The proxy device generates a DHCP request message and sends it to the CPE. The CPE receives the DHCP request message, generates a DHCP response message, and sends it to the proxy device. The DHCP response message includes the IP address of the core network element and the IP address of the proxy device. The proxy device receives the DHCP response message from the CPE and obtains the IP address of the core network element and the IP address of the proxy device from the DHCP response message.

[0179] The following is an example to illustrate the above Figure 1 The method shown is illustrated by examples. The following Example 1 describes the application in NR as an example, but the method is also applicable to LTE. In the following Example 1, the 5G toB expansion board is an example of a proxy device. The gNB is an example of a base station. The 5GC is an example of a core network element. The SCTP message, NAS message, N1 signaling, and bearer information containing control plane signaling are examples of control messages or signaling in control messages. The campus network is an example of a local area network where industry users are located. Enterprise-oriented (to-business, toB) data is an example of industry user data. Customer-oriented (to-customer, toC) data is an example of individual user data. The GTPU message containing to-B data or to-C data is an example of a service message.

[0180] This embodiment uses the 5G public network as backhaul for the 5G toB private network, which is plug-and-play and supports DIY delivery by campus owners.

[0181] Figure 2 A schematic diagram of an application scenario provided for an embodiment of the present application.

[0182] Figure 2 The scenario shown includes 5GC, campus network, gNB, 5G module, and campus equipment. The gNB includes a BBU and multiple RRUs. The BBU includes a 5G to B expansion board. In the traditional solution, the gNB is directly connected to the 5GC. Figure 2 As shown, in this embodiment, the gNB is connected to the 5G to B expansion board, and the 5G to B expansion board is then connected to the 5GC, that is, the 5G to B expansion board is connected in series between the gNB and the 5GC. Figure 2 As shown in the figure, after the 5G toB expansion board receives the service message (including user plane data, such as toB data) from the gNB, the 5G toB expansion board can forward the service message to the server in the campus network through the local diversion function.

[0183] After receiving control messages from the gNB (including control plane data, i.e., N2 interface data, such as SIM card account activation and access authentication), the 5G toB expansion board forwards the control messages to the operator's server in the 5GC. The remaining signaling and data can be closed locally, simplifying backhaul requirements.

[0184] This embodiment includes three parts.

[0185] 1. Implement the NG interface control plane proxy function on the expansion board.

[0186] 1.1. The 5G toB expansion board uses the 3GPP standard N2 and N3 interfaces with gNB and 5GC.

[0187] The 5G to B expansion board uses the NG interface control plane proxy mode. It acts as both an SCTP server and client, converting control plane signaling. Both the expansion board and the gNB, and the expansion board and the 5GC, utilize the 3GPP standard NG interface control plane.

[0188] Regarding the specific implementation of the 5G to B expansion board's control plane signaling conversion, when the 5G to B expansion board receives an SCTP message containing control plane signaling, it modifies the transmission sequence number and stream sequence number within the SCTP message. Furthermore, the 5G to B expansion board modifies the source address within the SCTP message, replacing the gNB's service IP address with the expansion board's service IP address. Furthermore, the 5G to B expansion board does not need to modify the control plane signaling content within the SCTP message, maintaining the control plane signaling content unchanged.

[0189] Figure 3 This is a signaling flow chart provided by this embodiment, such as Figure 3 As shown, the interaction process involving gNB, 5G toB expansion board, and 5GC includes the following S31 to S311.

[0190] S31. The network administrator configures the service IP, firewall IP, and network management IP on the 5G to B expansion board.

[0191] The service IP address is the IP address of the 5G to B expansion board itself, which is used when the 5G to B expansion board provides services. The firewall IP address is the IP address of the 5GC.

[0192] S32: The 5G to B expansion board generates an NG setup request. The 5G to B expansion board sends the NG setup request to the 5GC.

[0193] S33: The 5GC receives the NG setup request and generates an NG setup response. The 5GC sends an NG setup response. The 5G to B expansion board receives the NG setup response.

[0194] S34, the 5G toB expansion board, and the 5GC interact to complete the link establishment process between the N2 interface on the 5G toB expansion board and the N2 interface on the 5GC, and to complete the link establishment process between the N3 interface on the 5G toB expansion board and the N3 interface on the 5GC.

[0195] S35 and the 5G toB expansion board send the self-deployment configuration to the gNB.

[0196] S36: The gNB generates an NG setup request and sends it. The 5G toB expansion board receives the NG setup request.

[0197] S37: The 5G toB expansion board generates an NG setup response in response to the NG setup request. The 5G toB expansion board sends the NG setup response to the gNB.

[0198] S39, gNB and 5G toB expansion board interact to complete the link establishment process between the N2 interface on the gNB and the N2 interface of the 5G toB expansion board, and complete the link establishment process between the N3 interface on the gNB and the N3 interface of the 5G toB expansion board.

[0199] S310: The terminal generates and sends a message including N1 signaling.

[0200] S311 and 5G toB expansion boards intercept the payload in the message, re-encapsulate and forward it.

[0201] In the above process, NG setup request, NG setup response, N2 and N3 establishment are all 3GPP standard signaling processes.

[0202] In the above process, the 5G toB expansion board completes the standard NG interface establishment process with the gNB and 5GC respectively, so that the gNB and 5GC are unaware of the 5G toB expansion board, thereby realizing the NG interface control plane proxy function.

[0203] 1.2. Through the NG interface control plane proxy, after the link between the expansion board and 5GC is disconnected, the gNB connected users remain normal.

[0204] After 5GC and transmission network abnormalities occur, the cell and terminals connected to the network maintain normal operation, improving reliability and reducing the reliability requirements for the transmission network.

[0205] The specific algorithm is as follows: When the control plane link from the 5G toB expansion board to the 5GC is abnormally interrupted, the cell can still remain activated because the control plane link from the gNB to the 5G toB expansion board remains normal, and the user services in the connected state can operate normally and are not affected. Specifically, the 5G toB expansion board acts as an intermediate agent, and the link peer seen by the gNB is the 5G toB expansion board. Therefore, the link between the gNB and the 5G toB expansion board remains normal, and the gNB can maintain normal service. Among them, the control plane link from the 5G toB expansion board to the 5GC is the link from the NG interface on the 5G toB expansion board to the NG interface on the 5GC. The control plane link from the gNB to the 5G toB expansion board is the link from the NG interface on the gNB to the NG interface on the expansion board.

[0206] Figure 4 This is a schematic diagram of a link disconnection scenario provided by an embodiment of the present application. Figure 4 As shown in the figure, since a 5G to B expansion board is deployed between the 5GC and the gNB, when the control plane link from the 5G to B expansion board to the 5GC is abnormally interrupted, the control plane link on the gNB remains normal and the 5G to B campus network cell remains activated.

[0207] Terminals never lose connection: By modifying the timer configuration on the gNB, terminals that have been without service for a long time are switched to the Inactive state instead of the Idle state. The transition from the Inactive state to the Connected state can be directly restored without relying on the 5GC, making the entire process invisible to the 5GC. Specifically, the duration of the User Inactivity timer on the gNB is modified. For example, the duration of the User Inactivity timer is changed from 20 seconds to 0 (indicating that the terminal does not automatically enter the Idle state). Figure 5 A schematic diagram of terminal state switching is shown in FIG. Figure 5 As shown in the figure, if the terminal has no business for a long time, the terminal will switch from the connected state to the inactive state, and the core network will not be aware of it. If the terminal has business, it will directly recover from the inactive state to the connected state.

[0208] 1.3. Through the NG interface control plane proxy, 5GC is not aware of cross-BBU switching, and cross-BBU switching does not require NG interface control plane signaling.

[0209] In the standard inter-BBU handover process, when a terminal switches from a source gNB to a target gNB, the target gNB must notify the 5GC of the path switch. Specifically, the target gNB sends an NGAP Path Switch Request message (NGAP PATHSWITCH REQ) to the AMF, and the AMF sends an NGAP Path Switch Confirmation message (NGAP PATH SWITCH REQACK) to the target gNB. In the inter-BBU handover interaction process, only PATH switch signaling is relevant to the 5GC. Therefore, the key to 5GC unawareness in inter-BBU handover scenarios is to ensure that the PATHs of multiple BBUs are the same.

[0210] In this embodiment, the NG interface control plane signaling of the slave BBU is converged to the master BBU through the master BBU mode. The master BBU completes the proxy of the NG control plane. The 5GC only senses the master BBU but not the slave BBU. Therefore, the 5GC believes that the PATH is the same, thereby avoiding PATH switching signaling.

[0211] The master BBU implements the NG control plane proxy function. For the 5GC, the master BBU is the client of the NG control plane, and for the slave BBU, the master BBU is the server of the NG control plane.

[0212] The master BBU implements the conversion of NG control plane messages between the 5GC and the slave BBU, including the following functions (1) to (3).

[0213] (1) The master BBU distributes NAS messages and establishes a corresponding relationship between NAS messages and slave BBUs. The master BBU needs to uniformly replace the user identifiers on the base station side to prevent user identifier conflicts.

[0214] NAS messages are messages between the terminal and 5GC. The gNB does not parse the content of NAS messages.

[0215] When the master BBU receives a NAS message from a terminal, it forwards it to the AMF in the core network. When a terminal connected to the master base station sends a NAS message, the master BBU receives it via the link between the terminal and the master base station. When a terminal connected to a slave base station sends a NAS message, the slave BBU receives it via the link between the terminal and the slave base station. The slave BBU forwards the received NAS message to the master BBU via the link between the slave BBU and the master BBU.

[0216] When replacing the user identifier, for signaling related to the N2 interface, the master BBU replaces the user identifier assigned by the slave BBU carried in the signaling with the user identifier uniformly assigned by the master BBU. Optionally, the replaced user identifier used by the master BBU is obtained through negotiation between the expansion board of the master BBU and the core network.

[0217] (2) When establishing a bearer, the primary BBU is responsible for replacing the IP address in the bearer information.

[0218] The master BBU replaces the IP address in the bearer information as follows: the source IP address of the bearer information sent by the slave BBU is the slave BBU's IP address. After receiving the bearer information from the slave BBU, the master BBU replaces the source IP address with its own IP address. The master BBU then sends the bearer information with the replaced IP address to the core network.

[0219] (3) During inter-BBU switching, the primary BBU completes the refresh of the correspondence between the NAS message and the BBU (PATH switching is terminated and maintained at the primary BBU).

[0220] Figure 6 The architecture shown is an example of a scenario where a master base station and N slave base stations are deployed. The master BBU is the BBU in the master base station, and the slave BBU is the BBU in the slave base station. The expansion board in the BBU is an example of a proxy device. Other parts of the base station, such as RRU or AAU, antenna, etc. Figure 6 The master BBU and slave BBU both include a master control unit, a 5G to B expansion board ( Figure 6 The master BBU and each slave BBU are connected to the 5GC via a transmission network. An NG-C (NG control plane) link is established between the master control unit of the master BBU and the 5GC, and an NG-C link is established between the master control unit in the master BBU and the master control unit in each slave BBU.

[0221] 2. Local traffic diversion function

[0222] Based on the NG interface control plane agent, local diversion of the NG interface user plane of ToB data is realized on the expansion board.

[0223] Local traffic diversion refers to the identification of toC data and toB data on the 5G toB expansion board. The 5G toB expansion board forwards the toB data to the local server, and the 5G toB expansion board transparently transmits the toC data to the 5GC. This embodiment supports multiple traffic diversion strategies (including but not limited to the PLMN / slice ID / DNN / IP quintuple, etc.). The interfaces used by the 5G toB expansion board to communicate with the gNB and 5GC are all 3GPP standard N3 interfaces.

[0224] Among them, toB data refers to the company's own data, and toC data refers to personal data.

[0225] Figure 7 This is a signaling flow chart provided in this embodiment. Figure 7The interacting entities in the signaling process shown include the terminal, gNB, 5G toB expansion board, campus network, transmission network and 5GC. Figure 7 The signaling flow shown includes the following S41 to S410.

[0226] S41 and 5G toB expansion board establish NG interfaces with gNB and 5GC respectively.

[0227] S42. The terminal sends a NAS message and an access authentication message to request the establishment of a 5G LAN bearer.

[0228] The S43 and 5G toB expansion boards intercept the message payload, parse the ASN1, and obtain the uplink and downlink TEIDs.

[0229] When toB data and toC data are transmitted through a network, the 5G toB expansion board diverts the data according to PLMN, DNN or other service identifiers.

[0230] S44: When the 5G toB expansion board receives a service message containing toC data, it transparently transmits the toC data to the 5GC. The 5G toB expansion board determines whether it is ToC data based on the GTPU message header, without parsing the contents of the payload field in the message.

[0231] S45. The terminal sends a service message containing toB user data to the gNB.

[0232] S46: The gNB encapsulates the GTPU header into the service message, obtaining a GTPU message containing the toB user data. The gNB sends the GTPU message to the 5G toB expansion board via the N3 interface.

[0233] S47 and the 5G to B expansion board strip the GTPU header to obtain the service message. The 5G to B expansion board performs NAT processing on the service message according to the IP mode and sends the NAT-processed service message to the campus network.

[0234] Specifically, the 5G toB expansion board replaces the destination IP address in the service message from the IP address of the terminal allocated by the core network to the IP address of the enterprise user.

[0235] The 5G toB expansion board also learns IP and TEID entries in IP mode and MAC and TEID entries in 5G LAN mode. TEID is a common user identifier for both the control and user planes, and its role is to associate the control plane user identifier with the user IP address.

[0236] S48. The campus network sends the service message to the 5G toB expansion board.

[0237] S49, the 5G to B expansion board locates the corresponding terminal session based on the destination MAC address or IP address in the service message. The 5G to B expansion board performs NAT processing on the service message in IP mode and encapsulates the NATed service message with a GTPU header to generate a GTPU message. The 5G to B expansion board sends the GTPU message to the gNB.

[0238] S410: The gNB receives the GTPU message, removes the GTPU message header, obtains a service message containing user data, and sends the service message containing user data to the terminal.

[0239] In the above process, the 5G to B expansion board distinguishes between to-C and to-B data using service identifiers such as the PLMN / slice ID / DNN / IP quintuple. For to-C data, the 5G to B expansion board transparently transmits it to the 5GC without any processing. For to-B data, the 5G to B expansion board processes the GTPU header. From the gNB to the campus network, the 5G to B expansion board strips the GTPU header. From the campus network to the gNB, the 5G to B expansion board encapsulates the GTPU header based on the user identifier.

[0240] The GTPU header is the header of the communication protocol between the gNB and 5GC. GTPU is a protocol encapsulated within the IP packets carrying toB data. Therefore, before the 5G toB expansion board sends toB data to the enterprise network, it strips the GTPU header. Conversely, before forwarding toB data from the enterprise network to the gNB, the 5G toB expansion board re-encapsulates the GTPU header.

[0241] The PLMN / slice ID / DNN / IP quintuple is an identifier carried in the GTPU message header, which can be used to distinguish the GTPU messages of different users.

[0242] 3. 5G toB expansion board configuration-free activation

[0243] When using wireless self-backhaul, the 5G toB expansion board can be activated without configuration, thus simplifying the activation process.

[0244] Wireless self-backhaul refers to using the wireless public network as the backhaul channel for the private network. Generally, private network devices are connected to the CPE, and the CPE is connected to the wireless public network. Configuration-free activation means that there is no need to manually configure the source IP address and 5GC IP address on the 5G toB expansion board.

[0245] The configuration-free activation process is based on CPE automatic online and bridge mode. The configuration-free activation process includes the following steps (1) to (5).

[0246] Step (1) Install the designated SIM card on the return CPE.

[0247] This designated SIM card is configured with a special DNN when opening an account, and all other functions are the same as those of a normal SIM card.

[0248] Step (2) After the CPE is powered on, the DNS address (5GC IP address) and CPE service IP address are obtained according to the DNN configuration through the 3GPP standard process.

[0249] The process of CPE obtaining 5GC IP address and CPE service IP address adopts 3GPP standard process instead of DHCP process.

[0250] Step (3) The 5G toB expansion board obtains the IP service address and 5GC IP address from the CPE via DHCP.

[0251] Specifically, the CPE acts as a DHCP server and the 5G toB expansion board acts as a DHCP client. The 5G toB expansion board initiates a DHCP request to the CPE, and the 5G toB expansion board obtains the IP service address and 5GC IP address from the DHCP response returned by the CPE.

[0252] The IP service address obtained by the 5G toB expansion board is used as the source address of the message in the subsequent message forwarding process, and the 5GC IP address obtained by the 5G toB expansion board is used as the destination address of the message in the subsequent message forwarding process.

[0253] Step (4) CPE works in Bridge mode and is responsible for transparently transmitting the received 5GC data to the 5G toB expansion board, and transparently transmitting the received 5G toB expansion board data to 5GC.

[0254] Step (5) The 5G toB expansion board establishes an NG interface control plane link with the 5GC to complete the self-deployment process.

[0255] Figure 8 This is a schematic diagram of a network deployment scenario provided by this embodiment. Figure 8 As shown in the figure, the campus network is deployed with a 5G private network base station (gNB) and CPE. The private network base station is equipped with a 5G to B expansion board. The CPE is deployed between the 5G to B expansion board and the 5GC, providing wireless transmission between the 5G to B expansion board and the 5GC.

[0256] The 5G toB expansion board adopts different forwarding strategies for different data of campus terminals. When the 5G toB expansion board receives control plane data (such as NAS messages or other signaling) from the campus terminal, the 5G toB expansion board will send the control plane data to the CPE, and the CPE will forward the control plane data to the 5GC in the public network. When the 5G toB expansion board receives user plane data from the campus terminal, the 5G toB expansion board will forward the user plane data to the campus network. When the 5G toB expansion board receives operation and maintenance management plane data from the campus terminal, the 5G toB expansion board will process the operation and maintenance management plane data locally.

[0257] The technical effects of the above-mentioned Example 1 are introduced below, see (1) to (5) below.

[0258] (1) The 5G to B expansion board uses the 3GPP standard N2 and N3 interfaces with the gNB and 5GC. The gNB and 5GC are unaware of the 5G to B expansion board and do not require modification. Therefore, the 5G to B expansion board implements the NG interface proxy mode.

[0259] (2) The 5G toB expansion board implements the NG interface proxy mode, so that after the link between the expansion board and the 5GC is disconnected, the gNB supports the connected users to remain normal.

[0260] (3) The 5G toB expansion board implements the NG interface proxy mode. The 5GC is not aware of the cross-BBU switching, and the cross-BBU switching does not require the NG interface control plane signaling, thereby reducing the signaling between the base station and the core network. When the transmission between the base station and the core network is abnormally interrupted, the cross-BBU switching can be achieved without relying on the core network.

[0261] (4) The 5G toB expansion board implements the NG interface proxy mode, realizing local diversion of the NG interface user plane of ToB data, thereby realizing that enterprise business does not leave the enterprise park and ensuring the data security of the enterprise.

[0262] (5) When using wireless self-backhaul, the 5G toB expansion board can be activated without configuration.

[0263] Summarizing the solution of the above Example 1, it can be seen that the effects achieved by the above Example 1 include but are not limited to the following (1) to (3).

[0264] (1) The 5G toB expansion board uses the 3GPP standard N2 and N3 interfaces with the gNB and 5GC, and does not involve the N4 interface. Therefore, this solution does not have a traditional UPF sinking function.

[0265] (2) Since the N4 interface is not involved, the 5G toB expansion board does not involve signaling interaction with 5GC and can be decoupled from 5GC.

[0266] (3) Due to the use of standard N2 and N3 interfaces and proxy mode, it is possible to achieve "connected users remain normal after the link with 5GC is disconnected" and "5GC is not aware of cross-BBU switching."

[0267] The above example 1 is described by taking the application in the NR system as an example. Alternatively, this example can also be applied in the LTE system, in which case the NG interface in the above example 1 is replaced by the S1 interface in the LTE system.

[0268] Figure 9 FIG2 is a schematic diagram of the structure of a proxy device 700 provided in an embodiment of the present application. The proxy device 700 includes a receiving unit 701, a processing unit 702, and a sending unit 703. The receiving unit 701 is configured to support the proxy device 700 in executing S102. The processing unit 702 is configured to support the proxy device 700 in executing S103. The sending unit 703 is configured to support the proxy device 700 in executing S104.

[0269] Optionally, the receiving unit 701 is further used to receive an NG setup request sent by the base station (gNB) in S36; the processing unit 702 is further used to generate an NG setup response in S37; and the sending unit 703 is further used to send an NG setup response in S37.

[0270] Optionally, the processing unit 702 is further configured to generate an NG setup request in S32; the sending unit 703 is further configured to send the NG setup request in S32; and the receiving unit 701 is further configured to receive an NG setup response in S33.

[0271] Optionally, the receiving unit 701 is further used to receive a third control message from the core network element through the second link; the processing unit 702 is further used to generate a fourth control message based on the third control message; and the sending unit 703 is further used to send the fourth control message to the first base station through the first link.

[0272] Optionally, the third control message includes a NAS message, and the processing unit 702 is further configured to determine the first base station based on the NAS message and the first corresponding relationship.

[0273] Optionally, the receiving unit 701 is further configured to receive a handover message from the second base station, where the handover message indicates that the base station accessed by the first terminal is switched from the first base station to the second base station, and the first terminal is the initiator or destination of the NAS message in the first control message;

[0274] The processing unit 702 is further configured to update the first correspondence to a second correspondence, where the second correspondence is a correspondence between the NAS message and the second base station.

[0275] Optionally, the receiving unit 701 is further configured to receive a first service message, such as the toB data in S45 or the toC data in S44. The sending unit 703 is further configured to execute S47 if the type of service data in the first service message is industry user data; and to execute the step of transparently transmitting data in S44 if the type of service data in the first service message is individual user data.

[0276] Optionally, the processing unit 702 is also used to identify the type of business data in the first business message based on the business identifier carried by the first business message, where the business identifier includes the identifier of the public land mobile communication network PLMN, the identifier of the network slice, the data network name DNN, or at least one of the five-tuple.

[0277] Optionally, the first control message is received by the first base station from a third base station, and the third base station is a slave base station of the first base station. The processing unit 702 is used to replace the source Internet Protocol IP address of the first control message from the IP address of the third base station to the IP address of the first base station.

[0278] Optionally, the first control message is received by the first base station from a third base station, and the third base station is a slave base station of the first base station. The first control message includes a user identifier assigned by the third base station to the first terminal. The processing unit 702 is used to replace the user identifier carried by the first control message with the user identifier assigned by the first base station to the first terminal.

[0279] Optionally, the receiving unit 701 is also used to obtain the IP address of the core network network element and the IP address of the proxy device from the customer premises equipment CPE, the CPE is deployed between the proxy device and the core network element, and the CPE works in bridging mode; the sending unit 703 is also used to send the IP address of the core network network element and the IP address of the proxy device to the first base station.

[0280] Optionally, the processing unit 702 is configured to generate a Dynamic Host Configuration Protocol DHCP request message; the receiving unit 701 is configured to receive a DHCP response message from the CPE, where the DHCP response message includes the IP address of the core network element and the IP address of the proxy device.

[0281] It should be noted that the above embodiment provides only an example of the division of the above functional modules when proxy device 700 forwards messages. In actual applications, the above functions can be assigned to different functional modules as needed. That is, the internal structure of proxy device 700 can be divided into different functional modules to perform all or part of the functions described above. In addition, the proxy device 700 provided in the above embodiment and the method embodiment are based on the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0282] Figure 10 FIG. 8 is a schematic diagram of the structure of a proxy device 800 provided in an embodiment of the present application. The proxy device 800 includes at least one processor 801 , a memory 802 , and at least one network interface 803 .

[0283] The processor 801 is, for example, a general-purpose central processing unit (CPU), a network processor (NP), a graphics processing unit (GPU), a neural-network processing unit (NPU), a data processing unit (DPU), a microprocessor, or one or more integrated circuits for implementing the solution of the present application. For example, the processor 801 includes an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD is, for example, a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0284] The memory 802 is, for example, a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, an optical disc storage (including a compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. Optionally, the memory 802 exists independently and is connected to the processor 801 via an internal connection 804. Alternatively, the memory 802 and the processor 801 are optionally integrated together.

[0285] The network interface 803 uses any transceiver-like device for communicating with other devices or communication networks. For example, the network interface 803 includes at least one of a wired network interface and a wireless network interface. For example, the wired network interface is an Ethernet interface. For example, the Ethernet interface is an optical interface, an electrical interface, or a combination thereof. For example, the wireless network interface is a wireless local area network (WLAN) interface, a cellular network interface, or a combination thereof.

[0286] In some embodiments, the processor 801 includes one or more CPUs, such as the Figure 10 CPU0 and CPU1 are shown in the figure.

[0287] In some embodiments, the proxy device 800 optionally includes multiple processors, such as Figure 10 801 and processor 805 are shown in FIG. Each of these processors is, for example, a single-CPU or a multi-CPU. A processor herein optionally refers to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0288] In some embodiments, proxy device 800 further includes an internal connection 804. Processor 801, memory 802, and at least one network interface 803 are connected via internal connection 804. Internal connection 804 comprises a pathway for transmitting information between the aforementioned components. Optionally, internal connection 804 is a single board or bus. Optionally, internal connection 804 is divided into an address bus, a data bus, a control bus, and the like.

[0289] In some embodiments, the proxy device 800 further includes an input / output interface 806 . The input / output interface 806 is connected to the internal connection 804 .

[0290] Optionally, the processor 801 implements the method in the above embodiment by reading the program code 810 stored in the memory 802, or the processor 801 implements the method in the above embodiment by internally stored program code. In the case where the processor 801 implements the method in the above embodiment by reading the program code 810 stored in the memory 802, the memory 802 stores the program code that implements the method provided in the embodiment of the present application.

[0291] For more details on how the processor 801 implements the above functions, please refer to the descriptions in the previous method embodiments, which will not be repeated here.

[0292] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0293] A refers to B, which means that A is the same as B or A is a simple variant of B.

[0294] The terms "first" and "second" in the description and claims of the embodiments of this application are used to distinguish different objects, not to describe a specific order of objects, and should not be interpreted as indicating or implying relative importance. For example, the terms "first link" and "second link" are used to distinguish different links, not to describe a specific order of links, and should not be interpreted as implying that the first link is more important than the second link.

[0295] In the embodiments of the present application, unless otherwise specified, "at least one" means one or more, and "a plurality" means two or more. For example, a plurality of base stations means two or more base stations.

[0296] The above embodiments can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in accordance with the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0297] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A message forwarding method, characterized in that: The method comprises: A proxy device receives a first control message from a first base station through a first link, where the proxy device is deployed between the first base station and a core network element. The first link is a link between an NG interface on the proxy device and an NG interface on the first base station. The first control message includes a message header and first control plane signaling transmitted over the NG interface. The message header is a message header of a transmission protocol between the first base station and the core network. The proxy device generates a second control message based on the first control message, where the second control message includes the first control plane signaling; The proxy device sends the second control message to the core network element through a second link, where the second link is a link between an NG interface on the proxy device and an NG interface on the core network element.

2. The method according to claim 1, characterized in that Before the proxy device receives the first control message from the first base station through the first link, the method further includes: The proxy device receives a first NG establishment request from the first base station, where the first NG establishment request is used to request establishment of the first link; The proxy device generates a first NG establishment response, where the first NG establishment response indicates that the first link is successfully established; The proxy device sends the first NG setup response to the first base station.

3. The method according to claim 1 or 2, characterized in that Before the proxy device sends the second control message to the core network element through the second link, the method further includes: The proxy device generates a second NG establishment request, where the second NG establishment request is used to request establishment of the second link; The proxy device sends the second NG establishment request to the core network element; The proxy device receives a second NG establishment response from the core network element, where the second NG establishment response indicates that the second link is successfully established.

4. The method according to claim 1 or 2, characterized in that The method further comprises: The proxy device receives a third control message from the core network element through the second link, where the third control message includes second control plane signaling transmitted based on the NG interface; The proxy device generates a fourth control message based on the third control message, where the fourth control message includes the second control plane signaling; The proxy device sends the fourth control message to the first base station through the first link.

5. The method according to claim 4, characterized in that The third control message includes a non-access stratum (NAS) message. Before the proxy device sends the fourth control message to the first base station through the first link, the method further includes: The proxy device determines the first base station based on the NAS message and a first corresponding relationship, where the first corresponding relationship is a corresponding relationship between the NAS message and the first base station.

6. The method according to claim 5, characterized in that The method further comprises: The proxy device receives a handover message from a second base station, where the handover message instructs a base station accessed by a first terminal to be switched from the first base station to the second base station, where the first terminal is an initiator or a destination of a NAS message in the first control message; The proxy device updates the first correspondence to a second correspondence, where the second correspondence is a correspondence between the NAS message and the second base station.

7. The method according to any one of claims 1, 2, 5 or 6, characterized in that The method further comprises: The proxy device receives a first service message from the first base station through the first link; If the type of the service data in the first service message is data of an industry user, the proxy device forwards the first service message to the local area network where the industry user is located; If the type of the service data in the first service message is personal user data, the proxy device forwards the first service message to the core network element through the second link.

8. The method according to claim 7, characterized in that After the proxy device receives the first service message from the first base station through the first link, the method further includes: The proxy device identifies the type of service data in the first service message based on the service identifier carried by the first service message, where the service identifier includes an identifier of a public land mobile network PLMN, an identifier of a network slice, a data network name DNN, or at least one of a five-tuple.

9. The method according to claim 7, characterized in that The proxy device forwarding the first service message to the core network element through the second link includes: The proxy device forwards the first service message to the core network element through the second link in a transparent transmission manner.

10. The method according to claim 7, characterized in that The first service message includes a General Packet Radio Service Tunneling Protocol (GTPU) message header on the user plane, and the proxy device forwards the first service message to the local area network where the industry user is located, including: The proxy device strips the GTPU header of the first service message to obtain a second service message; The proxy device sends the second service message to the local area network where the industry user is located.

11. The method according to any one of claims 1, 2, 5, 6 or 8 to 10, characterized in that The first control message is received by the first base station from a third base station, where the third base station is a slave base station of the first base station, and the proxy device generates a second control message based on the first control message, including: The proxy device replaces the source Internet Protocol (IP) address of the first control message from the IP address of the third base station to the IP address of the first base station.

12. The method according to any one of claims 1, 2, 5, 6 or 8 to 10, characterized in that The first control message is received by the first base station from a third base station, where the third base station is a slave base station of the first base station. The first control message includes a user identifier allocated by the third base station to the first terminal. The proxy device generates a second control message based on the first control message, including: The proxy device replaces the user identifier carried in the first control message with the user identifier allocated to the first terminal by the first base station.

13. The method according to any one of claims 1, 2, 5, 6 or 8 to 10, characterized in that Before the proxy device receives the first control message from the first base station through the first link, the method further includes: The proxy device obtains the IP address of the core network element and the IP address of the proxy device from a customer premises equipment (CPE), the CPE is deployed between the proxy device and the core network element, and the CPE operates in a bridging mode; The proxy device sends the IP address of the core network element and the IP address of the proxy device to the first base station.

14. The method according to claim 13, characterized in that The proxy device obtains the IP address of the core network element and the IP address of the proxy device from the CPE, including: The proxy device generates a Dynamic Host Configuration Protocol DHCP request message; The proxy device receives a DHCP response message from the CPE, where the DHCP response message includes the IP address of the core network element and the IP address of the proxy device.

15. A proxy device, characterized in that: The proxy device includes: a receiving unit, configured to receive a first control message from a first base station through a first link, where the proxy device is deployed between the first base station and a core network element, the first link being a link between an NG interface on the proxy device and an NG interface on the first base station, the first control message including a message header and first control plane signaling transmitted over the NG interface, the message header being a message header of a transmission protocol between the first base station and the core network; a processing unit, configured to generate a second control message based on the first control message, where the second control message includes the first control plane signaling; The sending unit is configured to send the second control message to the core network element through a second link, where the second link is a link between the NG interface on the proxy device and the NG interface on the core network element.

16. A proxy device, characterized in that: The proxy device includes: a processor, the processor is coupled to a memory, the memory stores at least one computer program instruction, and the at least one computer program instruction is loaded and executed by the processor, so that the proxy device implements the method according to any one of claims 1 to 14.

17. A computer-readable storage medium, characterized in that The storage medium stores at least one instruction, and when the instruction is executed on a computer, the computer executes the method according to any one of claims 1 to 14.

18. A computer program product, characterized in that The computer program product comprises one or more computer program instructions, and when the computer program instructions are loaded and executed by a computer, the computer is caused to perform the method according to any one of claims 1 to 14.

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