A method and system for public and private network convergence

Abstract

The application relates to the field of mobile communication technology, in particular to a public and private network fusion method and system, which comprises the following steps: a core network base station receives a session establishment request of a non-public network terminal, judges a service type according to data network names in the request, if the service type is a public network service, the core network selects an anchor point user plane network element connected with the public network, initiates a cross-core network switching request, updates a non-public network cell global identity of the terminal into a public network cell global identity, and establishes a public network service channel. In the application, through cooperative signaling interaction between a non-public network and a public network core network and a context updating mechanism of a base station, seamless access of a single-card terminal to a public network service under private network coverage is realized, public network coverage deficiency in remote areas is solved, terminal hardware cost is reduced, a precise mapping of cell identities meets supervision requirements of a public network on roaming services, and data isolation and communication compliance are effectively guaranteed.

Description

Technical Field

[0001] This invention relates to the field of mobile communication technology, and in particular to a method and system for the convergence of public and private networks. Background Technology

[0002] Mobile communication technology refers to wireless communication that uses electromagnetic waves to propagate information in free space, and is widely used in personal communication, industrial internet, and the Internet of Things. Traditional multi-operator core network technology refers to a technical model where multiple operators share radio access network resources but each retains an independent core network architecture. Different operators' services are distinguished by a public terrestrial mobile network identifier, and terminal requests are routed to the corresponding core network. Instead of a public network (such as a private enterprise network), it operates as a completely independent and closed network architecture, with independent base stations and core networks, and data is strictly physically isolated from public networks.

[0003] However, under current technology, enterprise private networks are completely separated from public networks. This forces employees in remote and isolated environments such as mines and wind farms to use dual-SIM terminals or change their SIM cards to simultaneously meet their internal production communication and external public communication needs. This not only increases the cost and complexity of terminal hardware but also frequently leads to a lack of signal coverage due to the lagging construction of public network base stations in remote areas. Furthermore, directly using enterprise private network facilities to transmit public network services lacks an effective location identification mapping mechanism, making it impossible to meet operators' requirements for precise control over compliant data such as user roaming location and handover trajectories. This makes it difficult to achieve legal public network service access while ensuring data isolation. Summary of the Invention

[0004] To address the technical problems existing in the prior art, embodiments of the present invention provide a method for public-private network convergence, comprising the following steps: To achieve the above objectives, the present invention adopts the following technical solution: a method for public-private network convergence, comprising the following steps: The base station with multi-carrier core network function enabled receives session establishment requests sent by non-public network terminals and parses the data network name carried in the session establishment request through the non-public network access management network element. The non-public network access management network element sends a handover request message to the public network access management network element, triggering a roaming handover process from the non-public network to the public terrestrial mobile network; By receiving a handover command from the public network access management network element through the base station, the global identifier of the non-public network cell in the current context information of the non-public network terminal is updated to the global identifier of the public network cell.

[0005] As a further aspect of the present invention, a non-public network session management network element identifies public network service requirements based on the data network name, and after verifying the service subscription data, constructs an anchor user plane function network element path connecting to the public land mobile network. While maintaining a physical connection with the non-public network terminal, a service data transmission channel is established from the anchor user plane function network element to the public terrestrial mobile network.

[0006] As a further aspect of the present invention, the step of identifying public network service requirements based on data network names through a non-public network session management network element specifically includes: Extract the data network name string from the session establishment request; Match the data network name string with a pre-defined list of public network interoperability identifiers, which includes the ims or plmn-ims character field; If the match is successful, it is determined that the non-public network terminal requests to establish a public network service session, and the sinking user plane function network element that can connect to both the non-public network and the public network operator's service network is locked as the anchor user plane function network element.

[0007] As a further aspect of the present invention, the step of sending a handover request message from a non-public network access management element to a public network access management element specifically includes: After the anchor user plane function network element path is constructed, a cross-access management network element handover request is sent to the public network access management network element connected to the base station through the N14 interface; The cross-access management network element handover request encapsulates the current session information of the non-public network terminal, the identification information of the non-public network terminal, and the equipment identification information of the base station.

[0008] As a further aspect of the present invention, the operation of updating the global identifier of the non-public network cell in the current context information of the non-public network terminal to the global identifier of the public network cell specifically includes: The base station parses the handover command and verifies that both the source and target base stations are itself. Intercept wireless air interface handover commands targeting non-public network terminals and directly modify the context configuration of non-public network terminals in the base station's local storage unit; A handover notification message, including the updated global identifier of the public network cell, is generated and sent to the public network access management network element, indicating that the logical handover at the radio layer has been completed.

[0009] As a further aspect of the present invention, after establishing a service data transmission channel from the anchor user plane function network element path to the public terrestrial mobile network, the invention further includes: The public network access management network element sends a session context update request to the public network session management network element. The session context update request carries the updated public network cell global identifier and the address information of the anchor user plane function network element. By controlling the intermediate user plane function network element through the public network session management network element, the user plane connection between the intermediate user plane function network element and the anchor user plane function network element is established, thus completing the closed loop of the data link from the public network core network to the edge side of the non-public network.

[0010] As a further aspect of the present invention, it also includes: The system periodically acquires communication behavior data of non-public network terminals under the base station through public network access management network elements or public network session management network elements. The communication behavior data and the updated global identifier of the public network cell are reported to the operator's management system. The communication behavior data includes the communication start time, the communication duration, and the cell handover events that occur during the communication process.

[0011] As a further aspect of the present invention, before constructing the anchor user plane function network element path connecting to the public terrestrial mobile network, the method further includes: The non-public network access management network element or the non-public network session management network element is used to detect whether a non-public network terminal has an activated non-public network internal service session. Based on the local isolation policy, a session deactivation command is sent to the non-public network terminal to disconnect the user plane connection between the non-public network terminal and the enterprise's internal network.

[0012] As a further aspect of the present invention, a paging step for a non-public network terminal is also included: When the public land mobile network initiates a call request to a non-public network terminal, it queries the registration status of the non-public network terminal through the IP Multimedia Subsystem Home Subscriber Server. The current network location of the non-public network terminal is obtained through the non-public network unified data management network element, and a paging message is sent to the non-public network access management network element; After receiving a paging response from a non-public network terminal, the non-public network access management network element triggers a process to request the non-public network session management network element to reactivate the session, and executes a roaming handover process to connect the voice path to the public terrestrial mobile network.

[0013] As a further aspect of the present invention, the base station broadcast includes an information block comprising a public terrestrial mobile network identifier and a non-public network independent identifier, and the non-public network terminal is configured with a user identification module comprising a non-public network independent identifier, but without a public terrestrial mobile network user identification module.

[0014] A system for public-private network convergence, the system being used to implement the aforementioned method for public-private network convergence, the system comprising: The access request processing module performs the action of receiving session establishment requests sent by non-public network terminals through base stations with multi-carrier core network functions enabled, and parsing the data network name carried in the session establishment request. The path policy control module performs the action of identifying public network service requirements through non-public network session management network elements, and constructing anchor user plane function network element paths to connect to the public terrestrial mobile network after successful verification. The switching signaling interaction module executes the action of sending a handover request message from the non-public network access management network element to the public network access management network element, triggering the roaming handover process; The logical handover execution module executes the handover command responded to by the base station. While maintaining the physical connection unchanged, it updates the global identifier of the non-public network cell in the terminal context to the global identifier of the public network cell and establishes a cross-network service channel.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are as follows: This invention breaks through the limitations of traditional physical isolation by constructing a public-private network convergence mechanism based on logical switching. This enables single-SIM terminals to directly access public network services under the coverage of private network base stations, significantly reducing terminal costs and solving the problem of public network coverage blind spots in remote areas. Simultaneously, through dynamic cell identifier update technology in the base station context, compliant public network cell identifiers are provided to the operator's core network without physical switching. This satisfies national compliance controls on communication behavior while strictly ensuring the security and independence of enterprise intranet data through the isolation routing strategy of anchor user plane network elements. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the steps of the present invention; Figure 2 This is a system module diagram of the present invention. Detailed Implementation

[0018] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0019] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0020] Please see Figure 1 This invention provides a method for public-private network convergence, comprising the following steps: S1: The base station broadcasts an information block including a Public Land Mobile Network (PTN) identifier and a Non-Public Network Independent Identifier (NDI). The NDI terminal is configured with a User Identification Module (UIM) including the NDI, but not with a PTN UI. The base station, by enabling multi-operator core network functionality, receives session establishment requests from the NDI terminal and resolves the data network name carried in the session establishment request through the NDI access management network element.

[0021] The base station periodically transmits a main information block and information block type 1 on specific time-frequency resources of the downlink. Before the radio frequency unit performs signal modulation, the baseband processing unit constructs a broadcast message containing multiple network identification parameters. The public land mobile network identifier list field of this broadcast message simultaneously writes the mobile country code and mobile network code belonging to the public network, as well as the independent network identifier belonging to the non-public network. This independent network identifier uses a specific length of hexadecimal encoding to indicate that the cell supports non-public network access mode. The general-purpose integrated circuit card file integrated within the non-public network terminal only records the home network information matching the independent identifier of the non-public network; it does not pre-install any authentication keys or identifier files for public networks. When the non-public network terminal initiates the network selection process, the radio resource control layer scans the current frequency point, demodulates the synchronization signal block to obtain the physical cell identifier, and reads information block type 1. The terminal compares the network identifier in the broadcast message with the home identifier stored in the card bit by bit. When the two match completely, the cell is determined to be a candidate cell for camping. Upon completion of its stay and when it needs to initiate a service, the terminal initiates a random access procedure to the base station, sending a Radio Resource Control (RRC) connection establishment request. After the base station responds and establishes a signaling radio bearer, the terminal encapsulates a non-access stratum data packet through an uplink direct transmission message. The protocol discriminator field of this data packet indicates that it is a session management message, and the target data network name character sequence is explicitly filled in the protocol configuration options. After receiving this uplink data packet, the base station identifies that the message belongs to a non-public network slice and forwards it to the corresponding non-public network access management (NMR) element. The NMR element calls the packet data aggregation protocol parser to decapsulate the received NMR message, extract the key information elements in the session establishment request, and receives the session establishment request sent by the non-public network terminal through the base station with multi-carrier core network functionality enabled. The NMR element then parses the data network name carried in the session establishment request through the NMR element.

[0022] S2: Before constructing the anchor user plane function network element path connecting to the public terrestrial mobile network, it also includes: detecting whether there is an activated non-public network internal service session in the non-public network terminal through the non-public network access management network element or the non-public network session management network element.

[0023] Based on the local isolation policy, a session deactivation command is sent to the non-public network terminal to disconnect the user plane connection between the non-public network terminal and the enterprise's internal network.

[0024] The non-public network session management network element identifies public network service requirements based on the data network name, and after verifying the service subscription data, constructs an anchor user plane function network element path connecting to the public terrestrial mobile network.

[0025] The steps for identifying public network service requirements based on the data network name through non-public network session management elements specifically include: extracting the data network name string from the session establishment request.

[0026] Match the data network name string with a pre-defined list of public network interoperability identifiers, which includes the ims or plmn-ims character field.

[0027] If the match is successful, it is determined that the non-public network terminal requests to establish a public network service session, and the sinking user plane function network element that can connect to both the non-public network and the public network operator's service network is locked as the anchor user plane function network element.

[0028] The non-public network session management element first retrieves the terminal's current session context list in the core network database, checking the attributes of each active protocol data unit session one by one. If a session with a service quality flow identifier pointing to local intranet services (such as local video surveillance or machine control command streams) is found, a conflict is determined. Based on the local isolation policy, the session management element generates a session release command, with the reason value field set to "resource preemption caused by operator policy," and sends it to the terminal via non-access stratum signaling, sending a session deactivation command to the non-public network terminal and disconnecting the non-public network terminal from the enterprise's internal network user plane connection. Subsequently, the processing flow enters the public network service identification stage, where the non-public network session management element reads the data network name string extracted from the session establishment request and starts the string matching engine. The engine first loads a pre-defined list of public network interoperability identifiers, stored in a local cache. The matching process uses a character-by-character comparison logic: the first character of the input string is extracted and compared with the first character of the pre-defined list entry using its Askyn code value. If they match, the comparison continues with subsequent characters until a terminator is encountered. To verify this logic, the pre-defined identifier is set to "ims", and the input string is "ims-voice". The matching engine first determines the character length of the pre-defined identifier to be 3, then extracts the first 3 characters "ims" from the input string. The first character "i" (corresponding to decimal code 105) of the extracted segment is compared with the pre-defined first character; the result is equal. Similarly, "m" and "s" are compared. Finally, a prefix match is determined, and a successful match signal is output. If the input string is "local", the first 3 characters "loc" are extracted. The first character "l" (corresponding to decimal code 108) is not equal to "i" (105), so the match is directly determined to be unsuccessful. The steps for identifying public network service requirements based on data network names through non-public network session management network elements specifically include: extracting the data network name string from the session establishment request; matching the data network name string with a pre-set public network interoperability identifier list, which includes the `ims` or `plmn-ims` character range; if a match is successful, it is determined that the non-public network terminal is requesting the establishment of a public network service session. At this point, the network element needs to select a suitable user plane function network element. The selection logic is based on a network topology location database, filtering out network element nodes deployed at the network edge that simultaneously possess N3 interfaces (for base stations), N9 interfaces (for the public network core network), and N6 interfaces (for the local data network). The system evaluates the current load factor of the candidate network elements, which is obtained by calculating the ratio of current throughput to maximum processing capacity. For example, if candidate network element A has a current throughput of 800 Mbps and a maximum processing capacity of 1000 Mbps, its load factor is 0.8; if candidate network element B has a current throughput of 200 Mbps and a maximum processing capacity of 1000 Mbps, its load factor is 0.2.The control strategy sets the load balancing threshold to 0.7. The system will automatically remove network element A and lock the sinking user plane function network element that can connect to both non-public networks and public network operator business networks as the anchor user plane function network element. The non-public network session management network element identifies public network service requirements based on the data network name, and after verifying the service subscription data, it constructs a path to the anchor user plane function network element that connects to the public terrestrial mobile network.

[0029] S3: Send a handover request message from the non-public network access management network element to the public network access management network element to trigger the roaming handover process from the non-public network to the public terrestrial mobile network.

[0030] The communication link relies on the N14 interface, which connects the control plane of the non-public network to the control plane of the public network. After the anchor user plane function network element path is constructed, the non-public network access management network element starts the handover preparation state machine. First, the network element collects all context data of the current terminal, including: the terminal's security capability parameters (such as supported encryption algorithms and integrity protection algorithms), the current protocol data unit session resource list, the quality of service flow descriptor, and radio access bearer information related to the base station. Next, the network element constructs a cross-network element handover request signaling packet. In the message body of this signaling packet, the internal identifier of the non-public network terminal (such as the hidden form of the user permanent identifier) ​​is mapped to a roaming identifier that can be recognized by the public network. At the same time, the globally unique identifier of the base station is extracted and filled into the source access node identifier field. To ensure that the target network can accurately take over the session, a transparent container is also encapsulated in the signaling, which contains the radio resource control configuration information generated by the source base station.

[0031] The steps of sending a handover request message from a non-public network access management network element to a public network access management network element specifically include: after the anchor user plane function network element path is constructed, sending a cross-access management network element handover request to the public network access management network element connected to the base station through the N14 interface; The cross-access management network element handover request encapsulates the current session information of the non-public network terminal, the identification information of the non-public network terminal, and the equipment identification information of the base station.

[0032] The request is sent via a Hypertext Transfer Protocol version 2 (HTTP) data stream. Before sending, the packet size is checked. For example, if the terminal context information is 2048 bytes, the base station identification information is 64 bytes, and the header overhead is 128 bytes, the total packet size is 2240 bytes. This size will be checked to see if it exceeds the maximum transmission unit limit (e.g., 1500 bytes). If it does, fragmentation is performed, and the current session information of the non-public network terminal, the identification information of the non-public network terminal, and the equipment identification information of the base station are encapsulated in the cross-access management network element handover request.

[0033] S4: Receives a handover command from the public network access management network element through the base station. While maintaining a physical connection with the non-public network terminal, it performs the operation of updating the non-public network cell global identifier in the current context information of the non-public network terminal to the public network cell global identifier, and establishes a service data transmission channel to the public land mobile network via the anchor user plane function network element path.

[0034] The operation of updating the global identifier of the non-public network cell in the current context information of the non-public network terminal to the global identifier of the public network cell specifically includes: resolving the handover command by the base station and verifying that both the handover source base station and the target base station are themselves.

[0035] Intercept wireless air interface handover commands targeting non-public network terminals and directly modify the context configuration of the non-public network terminals in the base station's local storage unit.

[0036] A handover notification message, including the updated global identifier of the public network cell, is generated and sent to the public network access management network element, indicating that the logical handover at the radio layer has been completed.

[0037] After establishing the service data transmission channel from the anchor user plane function network element to the public land mobile network, the process also includes: sending a session context update request to the public network session management network element through the public network access management network element. The session context update request carries the updated public network cell global identifier and the address information of the anchor user plane function network element.

[0038] By controlling the intermediate user plane function network element through the public network session management network element, the user plane connection between the intermediate user plane function network element and the anchor user plane function network element is established, thus completing the closed loop of the data link from the public network core network to the edge side of the non-public network.

[0039] It also includes: periodically acquiring communication behavior data of non-public network terminals under the base station through public network access management network elements or public network session management network elements.

[0040] The communication behavior data and the updated global identifier of the public network cell are reported to the operator's management system. The communication behavior data includes the communication start time, the communication duration, and the cell handover events that occur during the communication process.

[0041] Upon receiving a handover command, the central control unit of the base station first performs an integrity check on the message to confirm that the command originates from a legitimate public network core network node. Subsequently, the base station parses the target cell identifier field in the command. Due to the use of multi-operator core network sharing technology, the physical layer parameters (such as frequency and scrambling code) of the target cell are completely consistent with the current source cell. Therefore, the base station determines that this is a logical handover rather than a physical hard handover. The base station immediately freezes downlink data transmission for the terminal and intercepts the air interface handover command generated by the radio scheduler to prevent the sending of physical layer reconfiguration messages to the terminal, thereby avoiding the interruption and reconstruction of the radio link. Simultaneously, the base station locates the terminal's context record in its memory database. This record contains the field "Serving Public Land Mobile Network Identifier." Before the handover, this field stored the identifier code of a non-public network (e.g., 460-99). The base station performs an atomic write operation, overwriting this field with the identifier code of the public network (e.g., 460-00). The system intercepts wireless air interface handover commands targeting non-public network terminals and directly modifies the context configuration of these terminals in the base station's local storage unit. After completing the memory update, the base station constructs a handover completion notification message containing the updated global cell identifier. A handover notification message including the updated global identifier of the public network cell is generated and sent to the public network access management network element, indicating that the logical handover at the radio layer has been completed. To quantify the performance advantages of this logical handover, an experiment compares the interruption latency of traditional physical handover with that of the logical handover proposed in this scheme. The experiment is set as follows: Under a network load of 50%, 100 handover events are statistically analyzed. As shown in Table 1, traditional physical handover requires steps such as radio frequency readjustment and random access, resulting in a significantly higher average latency than logical handover.

[0042] Table 1: Comparison of Mode Switching Latency

[0043] Referring to Table 1, logical soft handover reduces the total interruption latency from 40 milliseconds to 5 milliseconds, significantly improving service continuity. After establishing a service data transmission channel from the anchor user plane function network element to the public terrestrial mobile network, it also includes: sending a session context update request to the public network session management network element through the public network access management network element. The session context update request carries the updated global identifier of the public network cell and the address information of the anchor user plane function network element. The public network session management network element controls the intermediate user plane function network element to establish a user plane connection with the anchor user plane function network element, completing the data link closed loop from the public network core network to the non-public network edge. It also includes: periodically acquiring communication behavior data of non-public network terminals under the base station through the public network access management network element or the public network session management network element, starting a timer, and collecting data once every specific period (e.g., 900 seconds). The communication behavior data and the updated global identifier of the public network cell are reported to the operator's management and control system. The communication behavior data includes the communication start time, communication duration and cell handover events that occur during the communication process, and a service data transmission channel is established from the anchor user plane function network element to the public terrestrial mobile network.

[0044] S5: It also includes a paging step for non-public network terminals: When the public land mobile network initiates a call request for a non-public network terminal, it queries the registration status of the non-public network terminal through the IP Multimedia Subsystem Home Subscriber Server.

[0045] The current network location of the non-public network terminal is obtained through the non-public network unified data management network element, and a paging message is sent to the non-public network access management network element.

[0046] After receiving a paging response from a non-public network terminal, the non-public network access management network element triggers a process to request the non-public network session management network element to reactivate the session, and executes a roaming handover process to connect the voice path to the public terrestrial mobile network.

[0047] The call signal first arrives at the gateway mobile switching center or IP Multimedia Subsystem core node of the public network. Since the terminal is not directly registered in the public network's radio access network, the core network must first determine its routing information. The Home Subscriber Server (HSS) retrieves the user's registration entry from its database, finds that the user is in a "roaming to a non-public network" state, and records the corresponding non-public network access management element (NUMLE) identifier. The HIS obtains the terminal's current network location through the non-public network's unified data management element (UDA) and sends a paging message to the NUMLE. The public network core network sends a location information retrieval request to the NUMLE's UDA via the N8 or Nudm interface. The UDA queries its locally stored user context, confirms the tracking area list where the terminal is currently located, and routes the paging message to the NUMLE responsible for that area. This paging message carries the public network's temporary mobile subscriber identifier and a high-priority paging policy indication. The NUMLE, based on the tracking area list, sends paging requests to all base stations within its jurisdiction. The base stations calculate the terminal's paging frame number and paging timing. The calculation logic is as follows: the paging frame number equals the system frame number modulo the default paging period. Assuming the current system frame number is 1024, the default paging period is 128 frames, and the terminal identifier is 10, the paging location is determined using a specific hash algorithm. The base station broadcasts the paging record on the calculated time-frequency resources. The non-public network terminal decodes the paging message within its listening period, identifies its own identifier, and then initiates a service request process. Upon receiving the paging response from the non-public network terminal, the non-public network access management element triggers a process to request the non-public network session management element to reactivate the session and executes a roaming handover process to connect the call to the public terrestrial mobile network. This process, by reversing the logic of S1 to S4, establishes a dedicated voice bearer on the user plane. Experimental data shows that through this cross-network paging mechanism, the called party connection success rate remains at a high level. As shown in Table 2, 500 calls were tested, and the number of successful calls under different network conditions was recorded.

[0048] Table 2: Statistics on Cross-Network Paging Success Rate

[0049] Referring to Table 2, 198 calls were successfully connected in the idle network state, with a success rate of 99%; even in the congested state, the success rate remained above 91%, demonstrating the robustness of the paging mechanism. This high success rate is attributed to the high-priority scheduling strategy of paging messages within the non-public network.

[0050] Please see Figure 2 A public-private network convergence system includes: The access request processing module performs the action of receiving session establishment requests sent by non-public network terminals through base stations with multi-carrier core network functions enabled, and parsing the data network name carried in the session establishment request. The path policy control module performs the action of identifying public network service requirements through non-public network session management network elements, and constructing anchor user plane function network element paths to connect to the public terrestrial mobile network after successful verification. The switching signaling interaction module executes the action of sending a handover request message from the non-public network access management network element to the public network access management network element, triggering the roaming handover process; The logical handover execution module executes the handover command responded to by the base station. While maintaining the physical connection unchanged, it updates the global identifier of the non-public network cell in the terminal context to the global identifier of the public network cell and establishes a cross-network service channel.

[0051] The above embodiments illustrate preferred embodiments of the present invention. Any equivalent adjustments to the technical solution based on software engineering methods are within the scope of protection, including but not limited to: implementing algorithm logic using different programming languages, refactoring functional modules into services, adjusting data interaction protocols, and optimizing resource scheduling strategies. Any implementation scheme derived from reasonable modifications to the data processing flow, service call chain, or system architecture layer without departing from the core technology of the present invention should be considered within the protection scope defined by the technical solution of the present invention.

Claims

1. A method for integrating public and private networks, characterized in that, Includes the following steps: The base station with multi-carrier core network function enabled receives session establishment requests sent by non-public network terminals and parses the data network name carried in the session establishment request through the non-public network access management network element. The non-public network access management network element sends a handover request message to the public network access management network element, triggering a roaming handover process from the non-public network to the public terrestrial mobile network; By receiving a handover command from the public network access management network element through the base station, the global identifier of the non-public network cell in the current context information of the non-public network terminal is updated to the global identifier of the public network cell.

2. The method for public-private network convergence according to claim 1, characterized in that, The method also includes: The non-public network session management network element identifies public network service requirements based on the data network name, and after verifying the service subscription data, constructs an anchor user plane function network element path connecting to the public land mobile network. While maintaining a physical connection with the non-public network terminal, a service data transmission channel is established from the anchor user plane function network element to the public terrestrial mobile network.

3. The method for public-private network convergence according to claim 2, characterized in that, The step of identifying public network service requirements based on the data network name through the non-public network session management element specifically includes: Extract the data network name string from the session establishment request; The data network name string is matched with a preset list of public network interconnection identifiers, which includes the ims or plmn-ims character field; If the match is successful, it is determined that the non-public network terminal requests to establish a public network service session, and the sinking user plane function network element that can connect to both the non-public network and the public network operator's service network is locked as the anchor user plane function network element.

4. The method for public-private network convergence according to claim 2, characterized in that, The steps for the non-public network access management element to send a handover request message to the public network access management element specifically include: After the anchor user plane function network element path is constructed, a cross-access management network element handover request is sent to the public network access management network element connected to the base station through the N14 interface; The cross-access management network element handover request encapsulates the current session information of the non-public network terminal, the identification information of the non-public network terminal, and the equipment identification information of the base station.

5. The method for public-private network convergence according to claim 1, characterized in that, The operation of updating the global identifier of the non-public network cell in the current context information of the non-public network terminal to the global identifier of the public network cell specifically includes: The base station parses the handover command and verifies that both the source and target base stations are itself. Intercept the wireless air interface handover command for the non-public network terminal and directly modify the context configuration of the non-public network terminal in the base station local storage unit; A handover notification message including the updated global identifier of the public network cell is generated and sent to the public network access management network element, indicating that the logical handover at the radio layer has been completed.

6. The method for public-private network convergence according to claim 2, characterized in that, After establishing the service data transmission channel to the public terrestrial mobile network, the following is also included: The public network access management network element sends a session context update request to the public network session management network element. The session context update request carries the updated global identifier of the public network cell and the address information of the anchor user plane function network element. The public network session management network element controls the intermediate user plane function network element to establish a user plane connection with the anchor user plane function network element, thereby completing the closed loop of the data link from the public network core network to the edge of the non-public network. The communication behavior data of the non-public network terminal under the base station is periodically obtained through the public network access management network element or the public network session management network element. The communication behavior data and the updated global identifier of the public network cell are reported to the operator's management and control system. The communication behavior data includes the communication start time, the communication duration, and cell handover events that occur during the communication process.

7. The method for public-private network convergence according to claim 2, characterized in that, Before constructing the anchor user plane function network element path connecting to the public terrestrial mobile network, the following is also included: The non-public network access management network element or the non-public network session management network element is used to detect whether the non-public network terminal has an activated non-public network internal service session. Based on the local isolation policy, a session deactivation command is sent to the non-public network terminal to disconnect the user plane connection between the non-public network terminal and the enterprise's internal network.

8. The method for public-private network convergence according to claim 1, characterized in that, It also includes a paging step for the called party on the non-public network terminal: When the public land mobile network initiates a call request for the non-public network terminal, it queries the registration status of the non-public network terminal through the IP Multimedia Subsystem Home Subscriber Server. The current network location of the non-public network terminal is obtained through the non-public network unified data management network element, and a paging message is sent to the non-public network access management network element; After receiving the paging response from the non-public network terminal, the non-public network access management network element triggers a process to request the non-public network session management network element to reactivate the session, and executes the roaming handover process to connect the voice path to the public terrestrial mobile network.

9. The method for public-private network convergence according to claim 1, characterized in that, The base station broadcast includes information blocks of public land mobile network identifier and non-public network independent identifier. The non-public network terminal is configured with a user identification module including a non-public network independent identifier, but is not configured with a public land mobile network user identification module.

10. A system for the convergence of public and private networks, characterized in that, The system is used to implement the public-private network convergence method according to any one of claims 1-9, the system comprising: The access request processing module performs the action of receiving session establishment requests sent by non-public network terminals through base stations with multi-carrier core network functions enabled, and parsing the data network name carried in the session establishment request. The path policy control module performs the action of identifying public network service requirements through non-public network session management network elements, and constructing anchor user plane function network element paths to connect to the public terrestrial mobile network after successful verification. The switching signaling interaction module executes the action of sending a handover request message from the non-public network access management network element to the public network access management network element, triggering the roaming handover process; The logical handover execution module executes the handover command responded to by the base station. While maintaining the physical connection unchanged, it updates the global identifier of the non-public network cell in the terminal context to the global identifier of the public network cell and establishes a cross-network service channel.

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