An automatic network switching method based on different operator information sources on the multimodal eSIM terminal side

Abstract

The present invention relates to the field of wireless communication network technology, and discloses a method for automatic network switching based on different operator signal sources on the multimodal eSIM terminal side, comprising: while maintaining the active link of the primary operator, the terminal obtains the physical layer beacon signal of the backup operator in a passive monitoring manner and generates an inactivated shadow communication context; when it detects that the heartbeat persistence of the main link service layer fails, the optimal backup network is directly activated based on the shadow context. The present invention significantly reduces system overhead while ensuring business continuity through a network preparation state with zero signaling cost and a deterministic trigger mechanism. Its cross-protocol layer collaborative design enables the system to achieve user-unaware service migration in complex failure scenarios.

Description

Technical Field

[0001] The present invention relates to an automatic network switching method based on different operator information sources on a multi-modal eSIM terminal side, belonging to the technical field of wireless communication networks. Background Art

[0002] Current eSIM-based multi-operator switching technology generally adopts a breakpoint switching paradigm of disconnecting first and then reconnecting. The terminal must first disconnect the current link and then perform a full-band scan, network selection, and authentication process to reestablish the communication link. In this mode, when users conduct real-time services such as video conferencing or online payments, even if the signal strength transitions smoothly, business interruption will still occur due to the inherent delay of the switching process. Existing technologies attempt to alleviate this problem by optimizing switching decision algorithms, such as AI models based on signal prediction. However, their essence is still limited to the architectural paradigm of a single activated link and cannot avoid the deterministic damage of the switching action itself.

[0003] Specifically, existing technologies suffer from three fundamental limitations: First, the handover process inevitably involves service interruptions within seconds, making it difficult to meet real-time service continuity requirements; second, complex decision-making algorithms increase the computing burden on terminals while failing to resolve the paradox of misjudgment in signal transition zones; and third, the single-link architecture lacks redundancy, resulting in insufficient system resilience. While the industry has attempted to introduce network prediction or fast handover protocols, these have failed to address the core contradiction of link reconstruction overhead, and instead increased resource consumption due to additional signaling interactions.

[0004] With the rise of high-real-time services like cloud gaming and telemedicine, users are increasingly demanding seamless network switching. Architectural flaws in existing technologies create multiple bottlenecks in terms of service continuity, resource efficiency, and system robustness. The root cause lies in the inability to reconstruct a coordinated mechanism between active links and backup networks. Therefore, the technical problem addressed by this invention is how to achieve zero-disruption switching across carrier networks while ensuring service continuity and avoiding signaling storms and resource waste. Summary of the Invention

[0005] The present invention provides a method for automatic network switching based on different operator signal sources on the multimodal eSIM terminal side, the main purpose of which is to solve the problems of service interruption, low resource efficiency and insufficient system anti-fragility caused by the existing breakpoint switching paradigm.

[0006] To achieve the above objectives, the present invention provides a method for automatically switching networks based on different operator information sources on a multimodal eSIM terminal side, the method comprising the following steps:

[0007] Step a: The terminal selects a primary operator network and establishes an active communication link that carries user data;

[0008] Step b: The terminal selects at least one backup operator network in parallel and periodically receives the physical layer beacon signal broadcast by the backup operator network in a passive monitoring mode. The passive monitoring does not involve initiating any uplink signaling or connection request to the backup operator network.

[0009] Step c: Based on the beacon signal acquired through passive monitoring, the terminal locally generates and maintains an inactive shadow communication context, which pre-stores the cell identification information and tracking area information required for instantaneous establishment of a new link.

[0010] Step d, the terminal continuously monitors a service layer heartbeat status on the activated communication link, where the service layer heartbeat status is determined by a preset communication protocol, such as a message response status of a transmission control protocol or a user datagram protocol;

[0011] In step e, when it is detected that multiple consecutive message response times out in the service layer heartbeat status, and the number of consecutive message response timeouts reaches the preset switching trigger threshold, the terminal uses the shadow communication context to directly initiate a link activation request to the backup operator network with the largest beacon signal strength in the backup operator network to establish a new activation communication link.

[0012] Preferably, the service layer heartbeat status in step d is determined by monitoring the response status of a transmission control protocol maintenance connection, the preset switching trigger number threshold is an integer value greater than or equal to one, and the switching trigger number threshold is used to limit the number of consecutive message response timeouts for judging the persistent failure of the service layer heartbeat status.

[0013] Preferably, the passive monitoring in step b further includes decoding the system information block parameters broadcast by the backup operator network, the system information block parameters including access control related information or cell selection related information; and in the step e, if there are multiple backup operator networks, the priority of the link activation request excludes or lowers the priority of the backup operator network whose decoded system information block parameters indicate the existence of access restrictions or signaling congestion.

[0014] Preferably, in step a, the terminal selects the primary operator network based on at least one of its signal strength, network load information or user tariff preference.

[0015] Preferably, the system information block parameters indicate a backup operator network with access restrictions or signaling congestion, including access restriction (AC-Barring) parameters broadcast in the system information block, a cell reselection priority (cellReselectionPriority) value lower than a preset threshold, or access restrictions for specific service types, such as ordinary data services.

[0016] Preferably, the primary operator network and the backup operator network are different wireless communication networks, and the beacon signal specifically refers to the physical layer broadcast channel (PBCH) or synchronization signal block (SSB) information broadcast by each network base station at a fixed period.

[0017] Preferably, the method is applied to business scenarios where terminals conduct video conferencing, online payment, cloud gaming, or real-time voice communication, which have high requirements on network connectivity and latency.

[0018] Preferably, it also includes: in parallel with the response status monitoring of the transmission control protocol maintenance connection, the terminal periodically sends a quality probe heartbeat packet and measures its round-trip time (RTT); the terminal locally maintains a dynamic short-term historical baseline of the round-trip time of the quality probe heartbeat packet ; When the current round trip time is detected Consistently exceeds dynamic short-term historical baselines When the preset ratio threshold is reached, , where K is a preset coefficient greater than 1, and the preset proportional threshold indicates that the change in round-trip time reaches a level that requires attention. The terminal reduces its tolerance for the persistent failure of the transmission control protocol maintainable connection. The reduction in tolerance is manifested in reducing the preset handover trigger count threshold to accelerate the triggering of the link activation request.

[0019] Preferably, the shadow communication context is maintained only by parsing the public broadcast channel of the backup operator network on the terminal side, without occupying any wireless resources or signaling interaction on the backup operator network side.

[0020] Preferably, when the service quality of the activated communication link does not reach a preset minimum service quality standard, the method triggers a link activation request to ensure the continuity of user experience.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. By passively monitoring the physical layer beacon signals of the backup operator's network, the terminal locally generates and maintains an inactive shadow communication context without establishing an uplink connection. This mechanism keeps the terminal in a state of readiness without participating in the battle. This avoids the signaling storms and energy consumption burden caused by periodic attachment in traditional multi-network handovers, while providing a complete underlying parameter reserve for instantaneous link switching. This lightweight preparation method, which relies solely on broadcast channel analysis, reshapes the resource consumption paradigm of mobility management, significantly reducing total system overhead while ensuring business continuity.

[0023] 2. This approach abandons complex prediction models for physical layer signal fluctuations and instead uses the service layer heartbeat status as the sole criterion for link handover. By monitoring persistent failures of transport layer protocols, it accurately captures the actual risk of service interruption at the user level. When a service interruption occurs on the primary link, the terminal directly invokes the pre-synchronized shadow context to activate the optimal backup network. This fundamentally avoids the risk of misjudgment and ping-pong handovers in signal transition zones, significantly improving the efficiency of wireless resource management. During passive monitoring, the terminal simultaneously analyzes access control parameters in the System Information Block (SIB) and converts congestion management instructions broadcast by the operator into a basis for predicting network health. When a handover is required due to a primary link failure, the terminal prioritizes backup networks with access restrictions or low priority tags to avoid falling into strong signal congestion. This mechanism, combined with beacon strength assessment, forms a dual filter, upgrading handover target selection from simple physical layer measurement to a combined decision-making process of network intent analysis and signal evaluation, significantly improving the first-time handover success rate in complex congestion scenarios.

[0024] 3. Heartbeat interruption triggering and quality probe baseline drift form vertical synergy: When the quality probe detects that the round-trip delay continues to deviate from the historical baseline, the failure tolerance of the service heartbeat is dynamically reduced. This mechanism of degradation warning to sensitizing the main trigger enables the system to proactively switch in the early stages when the service has not been interrupted but the experience has degraded, such as cloud gaming lag. This expands the capability boundary of ensuring connectivity in traditional solutions to maintaining high-quality service continuity without introducing complex QoS monitoring models.

[0025] 4. The three-level in-depth defense is formed by physical layer beacon parsing to generate shadow context, transport layer heartbeat monitoring to determine main link failure, and application layer quality probe experience degradation warning. The physical layer preparation state eliminates switching delay, the transport layer provides deterministic failure judgment, and the application layer realizes early degradation perception. This cross-protocol layer coordination mechanism enables the system to maintain user-unaware service migration when facing complex failures such as sudden congestion, signal attenuation, and base station overload, which is significantly better than the existing layered and isolated solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a framework diagram of the multi-modal eSIM end-side network switching process of the present invention;

[0027] Figure 2 Schematic diagram of comparison between the primary network and the backup network under multi-dimensional performance indicators of the present invention;

[0028] Figure 3 This is a flowchart of the multi-modal eSIM side network switching triggering and link activation of the present invention.

[0029] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0030] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] The present application provides a method for automatically switching networks based on different operator information sources on a multi-modal eSIM terminal side, the method comprising the following steps:

[0032] Step a: The terminal selects a primary operator network and establishes an active communication link that carries user data;

[0033] Step b: The terminal selects at least one backup operator network in parallel and periodically receives the physical layer beacon signal broadcast by the backup operator network in a passive monitoring mode. The passive monitoring does not involve initiating any uplink signaling or connection request to the backup operator network.

[0034] Step c: Based on the beacon signal acquired through passive monitoring, the terminal locally generates and maintains an inactive shadow communication context, which pre-stores the cell identification information and tracking area information required for instantaneous establishment of a new link.

[0035] In step d, the terminal continuously monitors the status of a service layer heartbeat on the active communication link. The service layer heartbeat status is determined by the message response status of a preset communication protocol, such as the Transmission Control Protocol or the User Datagram Protocol. Specifically, to ensure that user privacy or sensitive information is not leaked during passive monitoring and shadow communication context generation, the present invention employs the following security and privacy protection mechanisms: First, passive monitoring is limited to receiving the physical layer beacon signals and system information block (SIB) parameters publicly broadcast by each operator. This information itself does not contain any user identification or service data. The terminal does not decrypt or deeply analyze the received broadcast data to obtain non-public information. Secondly, the generation and maintenance of shadow communication contexts are completed entirely locally on the terminal, without involving the exchange or upload of user data with any external network entity (including backup operator networks). The locally stored context information is limited to the cell identification information and tracking area information required to establish the link. These are general parameters for network access and are not associated with specific user behavior or identity. In addition, the internal design of the terminal strictly adheres to the principle of least privilege, allowing only authorized modules to access and process this context information. Encryption and sandbox isolation technologies are used to ensure that locally stored data is not accessed by unauthorized applications or processes. All processing flows do not generate or store any logs or metadata that can directly or indirectly be associated with the user's identity, thereby technically protecting user anonymity and data privacy. In addition, although the service layer heartbeat status is the primary criterion for link switching, in some special cases where network congestion does not cause heartbeat timeouts, the present invention can, for example, introduce an application layer quality probe early warning mechanism for collaborative processing. For example, the terminal monitors the response status of the transmission control protocol maintainable connection in parallel, periodically sends a quality probe heartbeat packet and measures its round-trip time (RTT). The terminal maintains a dynamic short-term historical baseline of the quality probe heartbeat packet round-trip time locally. When the current round trip time is detected Consistently exceeds dynamic short-term historical baselines When the preset ratio threshold is reached, , where K is a preset coefficient greater than 1. The preset proportional threshold indicates that the change in round-trip time has reached a level that requires attention. The terminal will reduce its tolerance for the persistent failure of the transmission control protocol maintainable connection. The reduction in tolerance is manifested as a reduction in the preset handover trigger count threshold. This mechanism enables the system to proactively switch at an early stage when the service has not been interrupted but the experience has degraded, thereby solving the problem of experience degradation caused by network congestion but heartbeat timeout. It expands the ability to ensure connectivity to maintain high-quality service continuity without introducing a complex QoS monitoring model.

[0036] In step e, when it is detected that multiple consecutive message responses of the service layer heartbeat status have timed out, and the number of consecutive message response timeouts reaches a preset switching trigger threshold, the terminal uses the shadow communication context to directly initiate a link activation request to the backup operator network with the largest beacon signal strength in the backup operator network to establish a new activation communication link; and in order to solve the problem that the shadow communication context may be inaccurate or invalid due to interference or changes in the broadcast channel information, the present invention adopts multiple robustness enhancement measures: first, the terminal will perform multi-cycle verification on the reception of the physical layer beacon signal and the decoding of the system information block (SIB), that is, the terminal will compare the broadcast information of the same backup network in multiple consecutive listening cycles. Only when the information remains consistent in the consecutive cycles or changes within an acceptable error range will it be included in or updated in the shadow communication context. If abnormal fluctuations or inconsistencies in the information are detected, the system will start a retry mechanism, and after confirming that the information is invalid or unreliable, the backup network will be temporarily marked as low priority or unavailable to avoid switching based on erroneous information. Secondly, the maintenance of the shadow communication context is not static, but dynamically updated. The terminal will periodically re-parse the latest broadcast channel information and promptly update the cell identification information, tracking area information, and system information block parameters (including access restrictions or cell selection related information) in the context to ensure that the context always reflects the latest status of the backup network. Even if the broadcast channel information is momentarily interfered with, the subsequent periodic update mechanism can promptly correct the error or restore accurate information. In addition, when making the final link activation request, the terminal will make a comprehensive judgment based on the current monitored real-time beacon signal strength and the pre-stored information in the shadow communication context. If there is a significant mismatch between the real-time signal and the pre-stored information, the system will give priority to trusting the real-time measurement data and compare and select it based on the information of multiple backup networks, further improving the accuracy and success rate of the switching decision, thereby reducing the impact of broadcast channel information interference or changes on the accuracy of the shadow communication context and enhancing the system's adaptability and robustness.

[0037] Preferably, the service layer heartbeat status in step d is determined by monitoring the response status of a transmission control protocol maintenance connection, the preset switching trigger number threshold is an integer value greater than or equal to one, and the switching trigger number threshold is used to limit the number of consecutive message response timeouts for judging the persistent failure of the service layer heartbeat status.

[0038] Preferably, the passive monitoring in step b further includes decoding the system information block parameters broadcast by the backup operator network, the system information block parameters including access control related information or cell selection related information; and in the step e, if there are multiple backup operator networks, the priority of the link activation request excludes or lowers the priority of the backup operator network whose decoded system information block parameters indicate the existence of access restrictions or signaling congestion.

[0039] Preferably, in step a, the terminal selects the primary operator network based on at least one of its signal strength, network load information or user tariff preference.

[0040] Preferably, the system information block parameters indicate a backup operator network with access restrictions or signaling congestion, including access restriction (AC-Barring) parameters broadcast in the system information block, a cell reselection priority (cellReselectionPriority) value lower than a preset threshold, or access restrictions for specific service types, such as ordinary data services.

[0041] Preferably, the primary operator network and the backup operator network are different wireless communication networks, and the beacon signal specifically refers to the physical layer broadcast channel (PBCH) or synchronization signal block (SSB) information broadcast by each network base station at a fixed period.

[0042] Preferably, the method is applied to business scenarios where terminals conduct video conferencing, online payment, cloud gaming, or real-time voice communication, which have high requirements on network connectivity and latency.

[0043] Preferably, it also includes: in parallel with the response status monitoring of the transmission control protocol maintenance connection, the terminal periodically sends a quality probe heartbeat packet and measures its round-trip time (RTT); the terminal locally maintains a dynamic short-term historical baseline of the round-trip time of the quality probe heartbeat packet ; When the current round trip time is detected Consistently exceeds dynamic short-term historical baselines When the preset ratio threshold is reached, , where K is a preset coefficient greater than 1, and the preset proportional threshold indicates that the change in round-trip time reaches a level that requires attention. The terminal reduces its tolerance for the persistent failure of the transmission control protocol maintainable connection. The reduction in tolerance is manifested in reducing the preset handover trigger count threshold to accelerate the triggering of the link activation request.

[0044] Preferably, the shadow communication context is maintained only by parsing the public broadcast channel of the backup operator network on the terminal side, without occupying any wireless resources or signaling interaction on the backup operator network side.

[0045] Preferably, when the service quality of the activated communication link does not reach a preset minimum service quality standard, the method triggers a link activation request to ensure the continuity of user experience.

[0046] Example 1: The present invention relates to a method for automatic network switching based on different operator sources on the multi-modal eSIM terminal side. By constructing an architecture where a primary link and a backup monitor coexist, combined with a shadow communication context maintenance mechanism, a service layer heartbeat status monitoring mechanism, and a quality probe judgment mechanism, low-latency, low-overhead, and imperceptible communication switching is achieved in a multi-operator network environment; specifically, the terminal first selects a primary operator network and establishes an activated communication link for carrying user data. This link is not only used for the transmission of current business data, but also constitutes the core path for the system to make real-time judgments on the communication status. The selection basis of the primary network may include indicators such as signal strength, current network load, and user tariff preferences. Any one or a combination of the above to ensure that the initial link has better connection quality; while maintaining the main link, the terminal passively monitors at least one backup operator network in parallel. The so-called passive monitoring means that the terminal does not need to initiate any uplink connection request or signaling interaction to the backup network, and only relies on the periodic reception and analysis of the beacon signal in the physical layer broadcast channel (such as PBCH or SSB) to achieve perception of the backup network. On this basis, the terminal locally generates and maintains at least one inactive shadow communication context, which pre-stores key parameters required for establishing the link, including cell identification information, tracking area identification, etc., so as to complete the pre-synchronization preparation of the backup link without occupying wireless resources.

[0047] In terms of link status perception, the terminal continuously monitors the service layer heartbeat status on the current primary link. This status can be determined by monitoring the confirmation response mechanism in the Transmission Control Protocol (TCP) to maintain the connection. When the system detects multiple consecutive heartbeat response timeouts and the number of timeouts reaches the preset switching trigger threshold, which is usually an integer not less than one, and the specific value can be flexibly set according to the business scenario, it is determined that the main link has failed; once the above conditions are met, the terminal does not need to rescan the frequency band or initiate the authentication process, but directly calls the corresponding parameters in the established shadow communication context, and initiates a link activation request to the target network with the strongest beacon signal strength in the backup operator network, quickly establishing a new communication link, thereby achieving smooth service migration. This process effectively avoids the complete access process required in traditional switching and significantly reduces switching latency. In order to improve the accuracy of network selection during the switching process, the terminal can also parse the system information block parameters from the backup operator network during the monitoring process, including access control parameters, cell reselection priority, etc. If there are access restrictions, signaling congestion indications or low priority marks in these parameters, the network will be excluded or its priority will be lowered, thereby avoiding the terminal from connecting to a network cell with strong signal but tight resources. This mechanism further introduces the analysis of network congestion status based on the judgment of physical layer signal strength, and realizes comprehensive evaluation and optimization selection of switching targets; in addition to the above mechanism, the present invention also introduces an application layer quality probe mechanism for realizing early identification of service experience degradation. The specific approach is: the terminal periodically sends quality probe heartbeat packets to the target server and measures its round-trip time (RTT), and maintains a dynamic short-term historical baseline value locally If the current round-trip time is continuously higher than the preset ratio threshold of the baseline value, the current round-trip time exceeds a certain multiple of K, which is a coefficient K greater than 1. The value range of K can be adjusted according to application requirements. The system believes that the current network quality is showing a downward trend and moderately reduces the tolerance for judgment of service layer heartbeat failure. Specifically, on the basis of maintaining the original heartbeat monitoring mechanism, the switching trigger number threshold is dynamically lowered to speed up the switching response speed and realize active migration before the service is interrupted. It is worth noting that all the above functions are completed locally by the terminal without relying on the core network or remote control server. It has good edge autonomy and deployment flexibility. Through the synergy between physical layer monitoring, transport layer monitoring and application layer probes, the present invention establishes a layered linkage, closed-loop response link switching mechanism, which can effectively deal with complex scenarios such as sudden network congestion, signal quality degradation or base station resource overload, and ensure that high real-time services such as cloud games, video conferencing, telemedicine or online payment can still maintain business continuity and experience stability during the communication network switching process.

[0048] At the same time, during the continuous operation of the multimodal eSIM terminal, in order to further enhance the availability of the communication link and the service continuity guarantee capability, the terminal locally introduces a robustness maintenance mechanism based on the dynamic evolution of state trends to support early perception of service quality degradation and active switching judgment. Its service quality degradation does not rely on an abstract user experience scoring system or unmeasurable fuzzy indicators, but is specifically composed of two aspects: first, the response continuity state of the currently activated communication link generated during the service layer connection maintenance process shows a downward trend, especially when there is a timeout response event within multiple heartbeat cycles but the switching trigger threshold is not reached; second, the shadow communication The beacon signal strength fluctuation amplitude of each backup operator network recorded in the message context during the continuous monitoring period exceeds the multiple level of the terminal's internal historical average, and there is no access restriction or congestion prompt in the corresponding system information block parameters. In this case, the terminal adjusts the preset switching trigger threshold to complete the link migration in advance before entering the main link failure breakpoint, thereby achieving low-loss connection of the communication link from the degraded state to the stable state, and when the service layer heartbeat state of the main operator network has not yet experienced continuous message failure but has shown a staged drift behavior, the terminal compares the round-trip time of the quality probe heartbeat packet with the dynamic short-term historical baseline. By comparing and judging, the internal sensitization mechanism is triggered, and the trigger judgment threshold is actively lowered, so that the system can complete the preparation for link pre-switching without losing the connection availability. This mechanism builds the system's operational flexibility in adverse environments through multi-dimensional collaborative construction, thereby ensuring that the service transmission path is not interrupted by isolated point breaks. In the specific engineering implementation, the inactive shadow communication context maintained by the terminal, in addition to the mean and timing of the original beacon signal, also synchronously records the intensity change difference and its standard deviation in the last three rounds of monitoring cycles, and inputs this data into the status evaluation module together with the number of consecutive heartbeat timeouts of the service layer as a complex measure of link stability and the urgency of switching needs. This mechanism does not rely on the participation of the external network side, does not introduce new signaling resource overhead, and does not need to rely on complex prediction models. It is completed entirely by the terminal based on the broadcast information and the built-in process of the protocol, ensuring an optimized technical balance between system resource consumption and service performance. By having the parameters for activating the backup link before the service is interrupted and adopting low-complexity, deterministic logic branches in the link state transfer judgment, the terminal avoids the core network interaction burden and wireless resource rescheduling overhead caused by link reconstruction in traditional switching scenarios, thereby forming a minimized configuration of signaling interaction behavior. These are all extended implementation methods that can be known to ordinary technicians in this field.

[0049] Example 2: This embodiment provides an end-side network switching solution suitable for multi-modal eSIM terminals. This solution constructs a communication switching mechanism with low latency, high stability and imperceptible characteristics for actual scenarios where there are multiple different operator network sources. It can meet the urgent needs of typical services with high real-time requirements, such as cloud games, video conferencing, online payments, etc. for service continuity during the communication process; specifically, after the terminal completes power-on initialization and loads multi-operator eSIM configuration files, the system may select a primary operator network based on preset rules including but not limited to user tariff preferences, historical connection quality, etc., and establish an initial activation link through a standard communication access process. The primary link not only assumes the transmission responsibility of the current business data, but also serves as the basis for subsequent link status judgment; after the main link is established, the terminal starts the monitoring module and periodically receives physical layer broadcast signals from other available operator networks without initiating any uplink connection requests or signaling interactions. The signals include but are not limited to synchronization signal blocks and physical broadcast channels. After each monitoring cycle, the terminal records the strength and timing information of the relevant beacon signal, and parses the system information block carried in the broadcast to obtain key information including cell reselection priority, access control parameters, broadcast frequency identifier, tracking area identifier, etc. Based on the above information, the terminal locally generates and maintains multiple inactive shadow communication contexts. The context stores all basic parameters required for subsequent link establishment in the form of a data structure, providing data support for rapid switching to the backup network after the main link fails, and does not occupy any wireless side resources during the maintenance period; in terms of link health monitoring, the terminal is equipped with a service layer heartbeat monitoring module, which relies on the TCP connection maintenance or UDP heartbeat mechanism on the main link, periodically sends heartbeat messages, and monitors their responses. When multiple heartbeat timeouts occur consecutively and the number of timeouts reaches the preset trigger threshold, which is generally set to an integer greater than or equal to one, and can be set according to specific business needs, the system determines that the main link has failed and prepares to activate the backup link.

[0050] In order to improve the responsiveness of the switching mechanism, the terminal is also equipped with a quality probe module, which operates independently of the service layer heartbeat mechanism and is responsible for sending quality probe packets to the target server at a fixed period and measuring its round-trip time. The terminal maintains a historical round-trip time baseline locally and updates it dynamically. If the current probe packet round-trip time continues to be higher than the preset ratio threshold of the baseline, the system determines that there is a significant downward trend in network quality and dynamically lowers the heartbeat failure judgment threshold accordingly, thereby activating the backup switching path in advance and realizing active pre-switching before the service is interrupted; after any of the above switching conditions is met, the terminal will select the optimal backup network based on the beacon strength of each backup network and the system information block parameters recorded in the shadow communication context. If some backup network broadcasts contain access restriction indications, load overload or low priority marks, the network will be automatically excluded or its switching priority will be lowered. After the system finally selects the target backup network, it directly calls the parameters in the corresponding shadow context to initiate a link activation request, skipping the traditional network scanning and authentication process to achieve fast link establishment. This mechanism greatly reduces the signaling overhead and delay during the switching process and improves the overall response efficiency of the system. To ensure system stability and user experience, the terminal is equipped with a state scheduling module to uniformly schedule the four states of primary link activation, backup network monitoring, quality probe warning, and backup link activation. The module switches between states according to the actual network conditions and event triggering conditions, coordinates the operating sequence and resource allocation of each sub-module, and avoids resource conflicts or logical dislocations. In addition, to prevent frequent switching from causing business instability, the system sets a cooling time window after completing a link switch. During this period, unless it is determined that there is serious quality degradation, a new round of switching judgment will not be triggered.

[0051] Example 3: In this example, in the current mobile communications field, especially in business scenarios with high real-time requirements, the traditional network switching mode has become increasingly difficult to meet users' expectations for a seamless communication experience due to the inherent limitations of service interruption and signaling overhead. To meet this challenge, this example aims to simulate a real urban mobile environment to verify the actual performance and engineering feasibility of the automatic network switching method based on the multimodal eSIM terminal proposed in this invention in ensuring business continuity and effectively reducing system overhead. This experiment constructed a test environment that simulates complex urban mobile scenarios, mainly including a multimodal eSIM terminal, a virtual base station group that simulates the operator's network functions, and a core network simulation platform for supporting communication processes. The multimodal eSIM terminal used has integrated software and hardware modules that support passive monitoring of physical layer beacon signals, can generate inactive shadow communication contexts, and can monitor the service layer heartbeat status and application layer quality probes in real time. The communication protocol stack inside the terminal is optimized to support collaborative decision-making across protocol layers. The virtual base station group includes three groups, each simulating the network of a different operator, denoted as operator A. (primary network), operator B (backup network one) and operator C (backup network two). Operator A is configured to have good initial coverage but controllable simulated signal attenuation or local congestion to trigger the scenario of continuous failure of the main link service layer heartbeat; operator B simulates stable coverage but can set local access restrictions; operator C simulates unstable coverage, large signal fluctuations or possible signaling congestion risks; the core network simulation platform provides necessary network functions and supports log recording and performance indicator monitoring. To simulate a real complex environment, multipath fading, shadow fading and various external interferences were introduced in the experiment through the RF fading simulator.

[0052] This experiment focuses on the system performance under two network switching trigger mechanisms: the first is the service layer heartbeat persistence failure trigger mechanism, in which the terminal continuously monitors the heartbeat message response status based on the Transmission Control Protocol (TCP) maintainable connection on the primary network (operator A). The heartbeat interval is set to 200 milliseconds, the message response timeout threshold is set to 500 milliseconds, and the switching trigger threshold, that is, the number of consecutive message response timeouts required to determine the main link service layer heartbeat persistence failure, is initially set to 3 times. This threshold is based on engineering experience in tolerance for real-time business service quality, and aims to balance system response speed and potential misjudgment; the second is the application layer quality probe early warning trigger mechanism The terminal periodically sends application layer quality probe packets to the preset target server and measures its round-trip time (RTT). The probe is sent once per second. The terminal maintains a dynamic short-term historical baseline locally, which is the sliding average of the RTT in the past 60 seconds. When the current round-trip time continues to exceed the dynamic short-term historical baseline by 1.5 times, the system determines that the network quality is deteriorating. At this time, the terminal will dynamically adjust the above-mentioned switching trigger threshold from 3 times to 1 time in order to speed up the network switching response. This dynamic adjustment strategy aims to reduce the judgment tolerance and realize active network switching when the service has not been completely interrupted but the user experience has shown a deterioration trend.

[0053] This experiment simulated typical business scenarios such as real-time online games and conducted multiple rounds of simulation runs, each lasting 10 minutes. At the beginning of the experiment, the terminal selected operator A as the primary network based on the initial signal strength and preset user preferences, and established an activated communication link that carries user data. While the primary link is activated, the terminal continues to passively monitor the physical layer broadcast channels of operators B and C, including the physical broadcast channel PBCH or synchronization signal block SSB information. This passive monitoring process does not involve initiating any uplink signaling or connection requests to the backup operator network. Based on the obtained beacon signal, the terminal locally generates and maintains an inactive shadow communication context, which pre-stores the cell identification information and tracking area information required to establish a new link. This mechanism effectively realizes network security with zero signaling cost. Network preparation status maintenance; during the test, the simulated signal strength of the primary network (operator A) was set to gradually attenuate from -80dBm to -110dBm. At the same time, the forwarding delay and packet loss rate of its core network simulation equipment were increased to simulate the signal attenuation and local network congestion that may occur in actual scenarios. The terminal continuously monitored the service layer heartbeat status on the activated communication link and the round-trip time of the application layer quality probe. When any preset network switching trigger condition was met, the terminal will immediately use its generated shadow communication context to directly initiate a link activation request to the backup operator network with the best current signal strength and the system information block indicating no access restrictions or congestion risks. After that, the system recorded the end-to-end delay from the network switching trigger to the activation of the new link and service recovery, and compared and analyzed the signaling interaction volume generated during the switching process.

[0054] The multi-modal eSIM terminal-side automatic network switching method proposed in the present invention showed predictable performance in multiple rounds of tests, and its system performance is shown in Table 1.

[0055] Table 1 System performance under different switching trigger mechanisms.

[0056]

[0057] Through experimental observation, in the service layer heartbeat persistence failure trigger mode, the average end-to-end delay from detecting the heartbeat persistence failure to activating the new link and restoring the service is about 65 milliseconds. In the application layer quality warning trigger mode, since the terminal triggers the network disconnection at the early stage of service experience degradation, the average delay is further shortened to about 40 milliseconds. In these two scenarios, the switching delay is significantly lower than the switching cycle of seconds or even longer in traditional solutions. This performance improvement is mainly due to the inactive shadow communication context pre-generated by the terminal, which effectively avoids time-consuming steps such as full-band scanning, network selection and authentication in the traditional switching process, thereby greatly shortening the link reconstruction time. Users only perceive a very low degree of instantaneous freeze in service continuity or even no perception at all. In terms of system overhead, the average signaling amount generated by the solution of the present invention during a single switching process is significantly reduced compared with the traditional solution. Since the terminal monitors the backup network passively and does not involve additional uplink signaling interaction or connection requests, the signaling storm that may be caused by periodic attachment in traditional multi-network switching is avoided. This result shows that the present invention can effectively reduce system resource consumption while ensuring business continuity. In addition, the intelligent network switching decision-making mechanism of this solution shows its rationality in a multi-operator coexistence environment. In the scenario where the primary network fails and there is a backup network with poor network health due to access restrictions or congestion, the terminal can prioritize or reduce the backup network with access restrictions or low priority marks based on the analysis of the backup operator network system information block (SIB) parameters. Even if such a network may show an advantage in signal strength, the terminal can still avoid selecting it. This strategy effectively avoids selecting a network with a strong signal but limited actual network service capabilities, thereby improving the accuracy of the switching decision and the success rate of the first network switching.

[0058] Example 4: This example combines Figures 1 to 3 , describes the implementation of the automatic network switching method based on different operator sources on the multi-modal eSIM terminal side. Figure 1As shown in the figure, the eSIM multi-module embedded in the terminal device supports access to multiple carrier signal sources. The system uses a primary / backup network selection mechanism to determine the primary carrier network and simultaneously selects at least one backup network. The selected primary network establishes an active communication link via the main link management module and continuously monitors the service layer heartbeat to detect any signs of communication failure. At the same time, the backup network uses a passive monitoring mechanism to monitor the backup network and does not actively initiate a connection. Instead, it obtains signal information through physical layer beacon parsing and locally generates a shadow context to store cell identification and tracking area information, thus implementing pre-synchronization preparation for the backup link. When the service layer heartbeat trigger is lost or the application layer perceives quality degradation, the system's built-in core architecture activates an intelligent response mechanism. Combining heartbeat anomalies with context state synchronization signals, the system completes network handover through quality probe warnings and optimal network selection. This mechanism achieves zero-signaling cost preparation, that is, the backup link is kept in a pre-warmed state without uplink signaling, reducing signaling overhead and ensuring user-unaware migration. Network handover is completed before the primary link fails or the user experience degrades, ensuring the continuity and stability of communication services.

[0059] like Figure 2 As shown in the figure, the horizontal axis indicates the performance evaluation dimension, and the vertical axis is the relative performance score of the primary network and the backup network under various indicators. In the figure, the primary network is represented by a solid line marked with a circle, and the backup network is represented by a dotted line marked with a diamond. Among them, the primary network performs better than the backup network in terms of transmission bandwidth and response speed; but in terms of signaling overhead and connection stability, the backup network has better performance, indicating that it is more efficient and reliable in the state without uplink signaling overhead preparation. In the signal strength dimension, the two perform similarly, with scenario-dependent fluctuations. The terminal device dynamically evaluates the availability of the primary / backup network locally based on the above dimensions, combines the service layer heartbeat monitoring and quality probe early warning mechanism, and realizes the optimal network selection and active network switching through intelligent judgment, thereby ensuring the continuity and stability of communication quality and user experience.

[0060] like Figure 3As shown, the process is based on the primary and backup carrier networks, which respectively handle primary link communication and backup signal source monitoring. The terminal, leveraging the parallel processing capabilities of its eSIM (eSIM card), establishes an activation link (carrying services) on the primary carrier network and detects persistent service-layer heartbeat failures. It also passively monitors the backup carrier network (physical layer beacons) and continuously monitors its status, while generating and maintaining an inactive shadow communication context to pre-store the parameters required for link activation. The system also features an application-layer quality probe warning (persistent RTT degradation) mechanism. This mechanism monitors round-trip latency trends using parallel probes and accelerates triggering when the detection results meet degradation conditions. If persistent service-layer heartbeat failures occur on the primary link, the system, in coordination with the warning mechanism, deterministically triggers a handover. Once the handover is triggered, the terminal directly activates the optimal backup network based on the backup context, eliminating the need for re-authentication or reconnection. This establishes a new activation link (enabling seamless user migration), ensuring continuity and low-latency handover for critical services such as video conferencing and cloud gaming in the event of sudden network degradation.

[0061] Example 5: In this example, in order to solve the problem of communication link interruption that may be caused by the sudden unavailability of the primary network during high-definition video conferencing, an embedded network switching module with the function of generating and maintaining shadow communication context is deployed on the terminal side, and combined with the service layer heartbeat monitoring mechanism and the application layer quality probe mechanism, fast, intelligent and user-imperceptible switching between cross-operator networks is achieved, thereby ensuring the continuity of delay-sensitive services and the stability of service quality. For example, a user uses a mobile terminal equipped with a multi-modal embedded user identification module for video conferencing. In the initial network connection stage, the terminal selects operator A as the primary network by comprehensively considering factors such as signal strength, network load, and user tariff policy, and establishes an activated communication link through a standard access process. At the same time, the terminal enables a passive monitoring mechanism to periodically receive synchronization signal blocks and system signals broadcast by operators B and C. The monitoring period is set to five seconds by default and is dynamically adjusted to three to ten seconds according to the current power consumption status of the terminal, so as to achieve a reasonable balance between coverage integrity and energy consumption control. During each round of monitoring, the terminal records the signal strength of the beacons broadcast by each operator and parses the content of the system information block contained therein. The information includes but is not limited to the cell identification code, access control parameters, cell reselection priority, broadcast frequency identifier and tracking area identifier. Based on the above information, the terminal builds an independent shadow communication context for each available network. The context is maintained in a structured data format and generates an independent entry for each operator network. The entry content includes network identifier, frequency number, average beacon signal strength, access restriction flag status and broadcast priority level. If a network is not detected in three consecutive rounds of monitoring, the terminal will mark the corresponding entry as unavailable and remove it from the current candidate list.

[0062] In order to improve the continuity guarantee capability of the communication link, the terminal activates the service layer heartbeat monitoring mechanism in parallel. This mechanism is based on the transmission control protocol on the main link to maintain the connection logic, sends a confirmation message every 500 milliseconds, and maintains the response counter in real time. When three consecutive messages do not receive a response, the system will preliminarily determine that the main link has lost stability and enter the switching warning state. In synchronization with this mechanism, the application layer quality probe module sends a quality probe message at a frequency of once per second, measures its round-trip time, and uses a sliding window to maintain a dynamic baseline with a window width of sixty seconds. If the current three consecutive probe round-trip times exceed 1.5 times the dynamic baseline, the system will determine that the network performance has a continuous deterioration trend, and accordingly start the dynamic threshold adjustment process of the service heartbeat monitoring mechanism, which will trigger the judgment threshold from Three consecutive heartbeat failures are adjusted to triggering a switch once, so as to improve the early warning response speed before the service is completely interrupted, thereby ensuring the continuity of terminal services; when the service layer heartbeat monitoring mechanism or the application layer quality probe mechanism meets any switching trigger condition, the terminal will retrieve all available backup network data in the shadow communication context, and sort them from high to low according to the beacon signal strength. Subsequently, the above ranking is weighted and adjusted based on the access restriction identifier and cell reselection priority information in the system information block broadcast by each backup network. If a network has an access restriction indication, broadcasts congestion prompt or has a priority lower than the preset level, the priority of the network will be lowered in the candidate ranking or directly excluded, ensuring that the selected target network has a high level of protection in terms of connection stability and service capability. After the terminal determines the target backup network, it will directly call the cell identification information and tracking area identifier pre-saved in the corresponding shadow communication context, bypassing the conventional frequency band scanning and network authentication process, and initiate a link activation request to the target network. The above activation process is completely based on local information on the terminal side and does not require additional signaling interaction with the core network, thereby significantly reducing network switching delay and system resource overhead. In test verification, the average switching response delay under this mechanism is significantly better than the traditional architecture, which can effectively improve the communication continuity of delay-sensitive services.

[0063] To further reduce the adverse effects of misjudgment or excessive switching, the system enters a cooling window period after each link switching is completed. The default setting of this window is fifteen seconds. During this period, the terminal freezes all new switching operations and only continues to perform beacon listening and link status monitoring. If the probe mechanism detects a significant deterioration trend in the network status during the cooling period, such as multiple consecutive round-trip delays exceeding twice the dynamic baseline, the system can interrupt the cooling window period and restart the switching process to avoid continued decline in service quality.

[0064] Example 6: This embodiment further enhances the actual adaptability of the system in complex wireless environments. First, while maintaining the normal operation of the primary link, the terminal continuously monitors the service layer response status through the existing connection maintenance mechanism. Unlike the traditional fixed judgment threshold, in this embodiment, the terminal forms a local short-term baseline status by additionally collecting the connection response history within a certain time window. The baseline is not exposed in the form of a numerical value, but is summarized and counted through the timeout counting mechanism already existing in the communication protocol layer, and is reasonably offset based on the communication status change trend. When the system detects that the service response continuity indicator deviates significantly from the baseline state and approaches the critical area before the failure threshold, it will automatically lower the handover trigger threshold so that the handover condition enters the sensitive state in advance before the actual service deterioration. The design logic of this mechanism does not rely on specific numerical values, but is based on the network status fluctuation range and transmission protocol tolerance threshold commonly used in this field. Local convergence of the response threshold is achieved through offset judgment logic, making the judgment more engineering controllable and operationally clear. Secondly, to ensure that the backup network selection process has more sufficient judgment support, the terminal introduces a structured extension field based on the original shadow communication context to describe the backup operator network of each monitored network. Additional environmental information: This context does not change the main structure design, but adds the following auxiliary fields based on the original record of cell identification code and tracking area identifier: average beacon signal reception strength, fluctuation amplitude in the last three rounds of monitoring, access restriction status of the most recently decoded system information block, and signaling load indicator bit status; this information is parsed locally by the terminal and updated regularly without relying on uplink communication or core network interaction. When selecting a backup network, the terminal will perform a multi-dimensional evaluation based on the above fields, and will no longer use signal strength as the only basis. For example, when a network has a high signal strength but there is an access restriction indication or historical monitoring fluctuations, When the amplitude is too large, the priority of the network in the sorting will be appropriately lowered to ensure that the switching target has the possibility of stable connection rather than just physical advantage, and to avoid business jitter caused by redundant switching, this embodiment also introduces a short suppression window period after the switching is successful. During this window period, the terminal continues to monitor the network status, but no longer triggers a new round of switching process, unless there is a clear failure signal in the service layer or the backup network status deteriorates extremely. This mechanism suppresses the waste of system resources that may be caused by frequent switching through logical delays, while improving the stability of network policy execution. These are all extended implementation methods that are known to ordinary technicians in this field.

[0065] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for automatic network switching based on different operator information sources on the multi-modal eSIM terminal side, characterized in that: The method comprises the following steps: Step a: The terminal selects a primary operator network and establishes an active communication link that carries user data; Step b: The terminal selects at least one backup operator network in parallel and periodically receives the physical layer beacon signal broadcast by the backup operator network in a passive monitoring mode. The passive monitoring does not involve initiating any uplink signaling or connection request to the backup operator network. Step c: Based on the beacon signal acquired through passive monitoring, the terminal locally generates and maintains an inactive shadow communication context, which pre-stores the cell identification information and tracking area information required for instantaneous establishment of a new link. Step d, the terminal continuously monitors a service layer heartbeat status on the activated communication link, where the service layer heartbeat status is determined by a message response status of a preset communication protocol; In step e, when it is detected that multiple consecutive message response times out in the service layer heartbeat status, and the number of consecutive message response timeouts reaches the preset switching trigger threshold, the terminal uses the shadow communication context to directly initiate a link activation request to the backup operator network with the largest beacon signal strength in the backup operator network to establish a new activation communication link.

2. The method for automatically switching networks based on different operator information sources on the multimodal eSIM terminal side according to claim 1, characterized in that: The service layer heartbeat status in step d is determined by monitoring the response status of a transmission control protocol maintenance connection. The preset switching trigger number threshold is an integer value greater than or equal to one, and the switching trigger number threshold is used to limit the number of consecutive message response timeouts for judging the persistent failure of the service layer heartbeat status.

3. The method for automatic network switching based on different operator information sources on the multimodal eSIM terminal side according to claim 1, characterized in that: The passive monitoring in step b further includes decoding system information block parameters broadcast by the backup operator network, the system information block parameters including access control related information or cell selection related information; And in the step e, if there are multiple backup operator networks, the priority of the link activation request excludes or reduces the priority of the backup operator network whose decoded system information block parameters indicate access restrictions or signaling congestion.

4. The method for automatically switching networks based on different operator information sources on the multimodal eSIM terminal side according to claim 1, characterized in that: In step a, the terminal selects the primary operator network based on at least one of its signal strength, network load information, or user tariff preference.

5. The method for automatically switching networks based on different operator information sources on the multimodal eSIM terminal side according to claim 1, characterized in that: The primary operator network and the backup operator network are different wireless communication networks. The beacon signal specifically refers to the physical layer broadcast channel or synchronization signal block information broadcast by each network base station at a fixed period.

6. The method for automatic network switching based on different operator information sources on the multimodal eSIM terminal side according to claim 2, characterized in that: Also includes: In parallel with the response status monitoring of the TCP maintainable connection, the terminal periodically sends a quality probe heartbeat packet and measures its round-trip time; The terminal maintains a dynamic short-term historical baseline of the round-trip time of the quality probe heartbeat packet locally ; When the current round trip time is detected Consistently exceeds dynamic short-term historical baselines When the preset ratio threshold is reached, , where K is a preset coefficient greater than 1, and the preset proportional threshold indicates that the change in round-trip time reaches a level that requires attention. The terminal reduces its tolerance for the persistent failure of the transmission control protocol maintainable connection. The reduction in tolerance is manifested as a reduction in the preset handover trigger count threshold.

7. The method for automatic network switching based on different operator information sources on the multi-modal eSIM terminal side according to claim 1, characterized in that: The shadow communication context is maintained only by the end-side parsing of the public broadcast channel of the backup operator network.

8. The method for automatic network switching based on different operator information sources on the multimodal eSIM terminal side according to claim 1, characterized in that: When the service quality of the activated communication link does not reach a preset minimum service quality standard, the method triggers a link activation request to ensure the continuity of user experience.

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