Dual-mode communication method and system

Abstract

The invention discloses a dual-mode communication method and system. According to the method, when a terminal performs service transmission in a first communication mode, stability information is obtained, and a prospective risk judgment basis is formed based on the stability information; when the prospective risk judgment basis meets a preset condition, starting a radio frequency and access process of a second communication mode to enable the second communication mode to enter an available state; when the two communication modes are in the available state at the same time, determining a main bearing communication mode and generating a corresponding data migration strategy; according to the main bearing communication mode and the data migration strategy, gradually transferring the service data to the main bearing communication mode for bearing; and after determining that the main bearer communication mode stably bears all service data, degrading or releasing non-main bearer communication resources, thereby realizing seamless switching of dual-mode communication. The method can effectively improve the continuity and reliability of communication switching, and is suitable for various heterogeneous network communication scenes.

Description

A dual-mode communication method and system Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a dual-mode communication method and system. Background Technology

[0002] With the development of mobile communication technology, communication terminals typically possess multiple communication capabilities, such as cellular communication and wireless LAN communication. Different communication modes have their own characteristics in terms of coverage, transmission rate, latency, and network load. In existing communication systems, terminals usually select or switch between different communication modes based on network availability or service requirements to adapt to complex and ever-changing communication environments and meet service transmission needs. Therefore, various dual-mode or multi-mode communication schemes have been proposed in related technologies to support communication terminals in completing service transmission under different network standards or communication modes.

[0003] In the aforementioned existing technologies, communication mode switching typically relies on real-time judgment of the current link status or network conditions. The switching process is often completed within a single communication mode, and the degree of coordination between different communication modes is limited. Under conditions of rapid changes in the communication environment or large fluctuations in link quality, existing solutions are prone to issues such as delayed switching triggering, communication interruptions, impact on service continuity, and low resource utilization efficiency, making it difficult to balance communication stability and smooth switching.

[0004] Therefore, it is necessary to provide a new technical solution to improve the overall communication experience of communication terminals when switching between multiple communication modes. Summary of the Invention

[0005] This application provides a dual-mode communication method and system to improve the continuity and reliability of communication switching.

[0006] This application provides a dual-mode communication method, comprising: continuously acquiring stability information, including signal quality, transmission errors, and service delay changes, during service transmission in a communication terminal using a first communication mode, and forming a forward-looking risk assessment basis to characterize the link degradation trend based on the stability information; when the forward-looking risk assessment basis meets preset conditions, initiating the radio frequency and access process of the second communication mode without terminating the service transmission in the first communication mode, so that the second communication mode enters an available state capable of carrying service data in parallel; when the first and second communication modes are simultaneously available, generating a selection result for the primary bearer communication mode and a corresponding data migration strategy, based on the link degradation trend and the channel conditions and network load conditions corresponding to the two communication modes; gradually transferring service data to the primary bearer communication mode for carrying according to the selection result of the primary bearer communication mode and the data migration strategy, while maintaining the consistency of session identifier, transmission sequence, and retransmission control state during the transfer process to achieve continuous service transmission; after confirming that the primary bearer communication mode has stably carried all service data, performing degradation or release processing on communication resources not used as the primary bearer communication mode, thereby completing the seamless switching of dual-mode communication.

[0007] This application provides a dual-mode communication method system, comprising: an acquisition unit, configured to continuously acquire stability information, including signal quality, transmission errors, and service delay changes, during service transmission in a communication terminal using a first communication mode, and to form a forward-looking risk assessment criterion based on the stability information to characterize link degradation trends; an initiation unit, configured to initiate the radio frequency and access process of a second communication mode without terminating service transmission in the first communication mode when the forward-looking risk assessment criterion meets preset conditions, thereby enabling the second communication mode to enter a usable state capable of carrying service data in parallel; and a generation unit, configured to simultaneously maintain the usability of both the first and second communication modes. In the current state, combining the link degradation trend and the channel conditions and network load corresponding to the two communication modes, a selection result for the primary bearer communication mode and the corresponding data migration strategy are generated; the transfer unit is used to gradually transfer the service data to the primary bearer communication mode for carrying according to the selection result of the primary bearer communication mode and the data migration strategy, and to maintain the consistency of session identifier, transmission sequence and retransmission control status during the transfer process to achieve continuous service transmission; the switching unit is used to perform degradation or release processing on the communication resources that are not used as the primary bearer communication mode after confirming that the primary bearer communication mode has stably carried all service data, thereby completing the seamless switching of dual-mode communication.

[0008] The beneficial effects of this application mainly include: (1) By forming a forward-looking risk judgment basis based on multi-dimensional stability information such as signal quality, transmission errors and service delay changes, the communication mode switching is transformed from a post-event response to an early trigger under trend perception, thereby reserving sufficient time for communication mode adjustment and effectively reducing the impact of sudden link degradation on service transmission stability. (2) The second communication mode is started in advance without interrupting the service transmission of the first communication mode, so that the second communication mode enters the available state that can carry service data in parallel, thereby forming an overlapping carrying interval between the two communication modes and avoiding the communication interruption problem caused by the failure of a single path during the traditional switching process. (3) Under the condition that both modes are available at the same time, the main carrying communication mode and data migration strategy are determined by comprehensively considering the link degradation trend, channel conditions and network load, realizing the dynamic optimization selection of communication carrying path, improving the overall transmission efficiency and enhancing the adaptability to complex network environments. (4) By maintaining the consistency of session identifier, transmission sequence and retransmission control state during the gradual migration of service data, the communication terminal can complete the communication mode switching without affecting the upper layer services, significantly improving service continuity and user experience, while reducing the system overhead caused by frequent session reconstruction. Attached Figure Description

[0009] Figure 1 is a flowchart of a dual-mode communication method provided in the first embodiment of this application.

[0010] Figure 2 is a schematic diagram of a dual-mode communication system provided in the second embodiment of this application. Detailed Implementation

[0011] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0012] The first embodiment of this application provides a dual-mode communication method. Please refer to Figure 1, which is a flowchart of the first embodiment of this application. The following describes the dual-mode communication method provided by the first embodiment of this application in detail with reference to Figure 1.

[0013] Step S101: During the process of service transmission using the first communication mode in the communication terminal, continuously acquire stability information including signal quality, transmission errors and service delay changes, and form a forward-looking risk judgment basis based on the stability information to characterize the link degradation trend.

[0014] In this invention, step S101 is the fundamental step of the entire dual-mode communication method. Its core function is to provide a reliable, quantifiable and forward-looking judgment basis for the pre-activation of the subsequent communication mode, the selection of the main bearer, and the data migration.

[0015] Specifically, during the service transmission process using the first communication mode, "continuous acquisition of stability information" means that the communication terminal does not perform a one-time detection at a single moment or within a single period during service transmission, but rather collects multiple parameters reflecting the current operating status of the communication link in real time or near real time according to a preset sampling period or event triggering mechanism. The stability information includes at least three types of information: signal quality, transmission errors, and service delay changes. Among them, signal quality refers to the set of parameters used to characterize the transmission conditions of the physical layer or link layer of wireless or wired communication links, such as received signal strength indication value, signal-to-noise ratio, reference signal reception quality, carrier-to-interference ratio, or equivalent parameters; transmission errors refer to the statistical results of bit errors, packet errors, or retransmission events that occur within a predetermined statistical window, such as block error rate, number of retransmissions, packet loss rate, etc.; service delay changes refer to the changes in the transmission delay experienced by service data from the sending end to the receiving end over multiple consecutive statistical periods, which can usually be characterized by calculating the average, variance, or jitter amplitude of round-trip delay, queuing delay, or end-to-end delay.

[0016] In this invention, "continuous acquisition" does not require that all types of stability information use the exact same sampling period or statistical window. Instead, it allows setting the sampling frequency according to the variation characteristics of different parameters. For example, signal quality parameters can be collected at millisecond or subframe levels, transmission error parameters can be accumulated over several data frames or several seconds as a statistical window, and service latency variations can be statistically analyzed using a sliding time window on multiple consecutive measurements. Those skilled in the art can reasonably configure the sampling period and statistical window according to the specific communication standard or terminal implementation conditions without affecting the implementation of this step.

[0017] After obtaining the aforementioned stability information, the communication terminal needs to "form a forward-looking risk assessment basis based on the stability information to characterize the link degradation trend." The "link degradation trend" refers to the direction and rate of change of the communication link from a stable state to an unstable state over a period of time. This trend is not a momentary anomaly of a single parameter, but rather is reflected through the comprehensive changes of multiple stability information over time. For example, when the received signal strength shows a continuous decrease over multiple consecutive sampling periods, the block error rate shows a gradual increase within the same time window, and the jitter of service latency significantly increases, it can be considered that the current communication link exhibits a degradation trend.

[0018] "Proactive risk assessment criteria" refers to a judgment result used to assess the risk of link performance degradation or unavailability in the future. This judgment result is not based solely on the stability information at the current moment, but is obtained by analyzing the direction and magnitude of changes in stability information in conjunction with historical sampling data. In specific implementation, trend indicators can be constructed for each type of stability information. For example, the slope of the linear change of signal quality parameters over N consecutive sampling periods can be calculated, the growth rate of block error rate within a continuous statistical window can be calculated, or the magnitude of change in service latency jitter between adjacent time windows can be calculated. Then, according to preset weights or rules, the above trend indicators are combined to form a comprehensive judgment result that reflects the overall degradation risk of the link.

[0019] For example, in a specific implementation, the signal quality trend index can be set as the average value of the signal-to-noise ratio change over the most recent 5 sampling periods, the transmission error trend index can be set as the weighted average value of the block error rate increase over the most recent 3 statistical windows, and the service delay trend index can be set as the standard deviation change of the delay measurement results over the most recent number of times. When at least two of the above trend indices simultaneously exceed their respective trend thresholds, or when the overall judgment result exceeds the preset risk judgment threshold, the formed forward-looking risk judgment basis can be considered valid, thereby indicating that the current first communication mode has a high risk of link degradation in the future.

[0020] It should be noted that this invention does not limit the forward-looking risk assessment criteria to adopt a specific mathematical model or algorithm. The above examples are only used to illustrate how to transform stability information into an operable risk assessment criterion.

[0021] Furthermore, the method for forming a forward-looking risk assessment criterion based on stability information to characterize link degradation trends includes: in the communication terminal, synchronously sampling changes in signal quality, transmission errors, and service delays according to a preset sampling rhythm, and performing time alignment processing on different types of stability information based on the sampling timestamp to form a set of stability feature vectors describing the link operating status within the same observation period; based on the set of stability feature vectors, calculating the change direction identifier and change amplitude parameter for each type of stability information within multiple consecutive observation periods, and combining the change direction identifier and change amplitude parameter to form a stability trend description set, wherein the stability... A qualitative trend description set is used to characterize the trend features of the link state evolving from stable to unstable. A consistency constraint judgment is performed on the stability trend description set to determine whether the change direction indicators of at least two types of stability information meet the preset cooperative degradation conditions within the same time window. When the cooperative degradation conditions are met, a trend validity marker is generated to indicate the continuous validity of the current link degradation trend in the time dimension. Under the constraint of the trend validity marker, the potential impact of link degradation is quantitatively evaluated based on the change magnitude parameter, and a risk intensity parameter associated with the trend validity marker is generated. The risk intensity parameter and the trend validity marker are used together as the basis for the forward-looking risk judgment.

[0022] A communication terminal refers to a terminal device capable of simultaneously operating a first communication mode and a second communication mode. Examples include mobile terminals with cellular and wireless LAN communication capabilities, industrial gateways, vehicle-mounted communication units, or other devices with dual-mode communication capabilities. A communication terminal typically includes a radio frequency front-end, a baseband processing unit, a protocol stack processing unit, and a service processing unit. In this embodiment, the calculation and determination process can be implemented by the protocol stack processing unit, the service processing unit, or a combination thereof, or it can be executed by the control processor within the terminal, as long as it can read relevant measurement and statistical data and complete the determination.

[0023] Stability information is a collective concept, encompassing at least three categories: signal quality, transmission errors, and service delay variations. Signal quality refers to a set of measurement parameters reflecting the physical link transmission environment, which can include received signal strength indication, signal-to-noise ratio (SNR), reference signal reception quality, or equivalent metrics. Transmission errors refer to a set of statistical parameters reflecting link reliability, which can include block error rate, packet loss rate, retransmission count, or equivalent metrics. Service delay variations refer to a set of metrics reflecting the stability of service transmission over time, which can include changes in end-to-end delay, changes in round-trip delay, jitter amplitude, or equivalent metrics. For ease of implementation, those skilled in the art can select one or more specific available metrics as input for each type of information, and can choose different sources depending on the communication standard. For example, cellular communication can obtain data from baseband measurements and protocol statistics, while wireless LANs can obtain data from drivers or protocol stacks.

[0024] In communication terminals, synchronous sampling of signal quality, transmission errors, and service delay changes according to a preset sampling rhythm refers to the terminal setting a sampling period for observing link status. This ensures that within each sampling period, the terminal can obtain the values ​​or statistical results of these three types of information at the same observation time point or within the same observation window. The "preset sampling rhythm" here needs to be clearly defined as a configurable sampling period and statistical window length. The sampling period determines the sampling trigger frequency, and the statistical window determines the cumulative range of transmission errors and delay-related indicators. For example, the sampling period can be set to 100 milliseconds or 500 milliseconds, while statistics such as block error rate and retransmission count can be accumulated within the same sampling period using a sliding window. End-to-end delay changes can be calculated as the mean and jitter within the same period. Synchronous sampling does not require that the three types of information be completely from the same source or generated at the same moment. Rather, it requires that the three types of information ultimately used for subsequent judgment have a corresponding relationship within the same observation period. Therefore, timestamps are needed for alignment.

[0025] Time alignment of different types of stability information based on sampling timestamps refers to assigning a unified timestamp identifier to each sample or statistical window, and mapping the signal quality value, transmission error statistics, and service delay variation value within that timestamp range to the same observation period. Alignment methods can be "nearest neighbor alignment" or "window inclusion alignment." Taking window inclusion alignment as an example, if the observation period is [t_k, t_k+T), then the average signal quality measurement, cumulative transmission error value, and service delay variation statistics within that time range are recorded as representative values ​​for that period, making data from different sources comparable in the time dimension. After alignment, a set of stability feature vectors describing the link's operating status within the same observation period is formed. A stability feature vector is a vector formed by organizing multiple stability information indicators within the same observation period according to a fixed dimension. For example, in observation period k, the vector can be represented as (signal quality indicator_k, transmission error indicator_k, service delay variation indicator_k). The set of stability feature vectors refers to the collection of multiple vectors formed within multiple consecutive observation periods, used for subsequent trend calculations.

[0026] Based on a set of stability feature vectors, the change direction identifier and change magnitude parameter are calculated for each type of stability information over multiple consecutive observation periods. This involves determining the direction and quantifying the magnitude of the change in each indicator over time. The change direction identifier is a symbolic quantity with a defined set of values, used to describe the direction of change of the indicator in the current observation period relative to the previous observation period. For example, it can be defined as three states: rising, falling, and basically unchanged. To avoid ambiguity, this application can adopt explicit judgment rules: if the indicator value of the current period minus the indicator value of the previous period is greater than a preset small change threshold, the change direction identifier is rising; if it is a negative value less than the threshold, it is falling; if the absolute value does not exceed the threshold, it is basically unchanged. The small change threshold can be set according to the indicator's dimensions. For example, the threshold for signal-to-noise ratio measured in decibels can be set to one decibel, the threshold for block error rate measured in proportion can be set to 0.01, and the threshold for delay change measured in milliseconds can be set to five milliseconds. The change magnitude parameter is a real number used to quantify the magnitude of the change, and can be directly expressed as a difference or a relative rate of change. To facilitate the standardization of indicators with different dimensions, those skilled in the art can define the magnitude of change parameter as a normalized change, for example, by dividing the difference between the current value and the previous value by the absolute value of the previous value and adding a constant to prevent division by zero, thus obtaining the relative magnitude of change. The aforementioned direction and magnitude are calculated separately for each type of indicator and formed into a sequence over multiple consecutive observation periods.

[0027] Combining the direction of change identifier with the magnitude of change parameter to form a stability trend description set means creating a description pair for each type of indicator in each observation period, for example (direction identifier_k, magnitude parameter_k), and forming corresponding description pair sequences for the three types of indicators, thus obtaining a set of descriptions that can characterize the evolution trend of the link state over time. This stability trend description set is used to characterize the trend characteristics of the link state evolving from stable to unstable. Specifically, when the signal quality shows a continuous downward trend and the magnitude of the decline continues to increase, the transmission error shows a continuous upward trend and the magnitude of the increase continues to increase, and the service delay change shows a continuous upward trend or jitter increase, it can be considered that the link is evolving from stable to unstable.

[0028] The so-called consistency constraint judgment means that a risk is not established simply because a single indicator shows an adverse change. Instead, it requires that the direction indicators of changes in at least two types of stability information satisfy a preset co-degradation condition within the same time window. The co-degradation condition is a clear logical condition that specifies that the directional changes of multiple indicators should exhibit a consistent degradation correlation. For example, it can be defined as follows: within the same time window, the signal quality direction indicator decreases, and the transmission error direction indicator increases; or the signal quality direction indicator decreases, and the service delay change direction indicator increases; or the transmission error direction indicator increases, and the service delay change direction indicator increases. To improve reliability, this time window can be defined as L consecutive observation periods, requiring the above co-degradation condition to be satisfied at least M times, or continuously satisfied N times, within this window. The technical significance of this is to filter out misjudgments caused by single-point fluctuations, instantaneous congestion, or occasional errors, thereby making the risk judgment basis forward-looking and stable.

[0029] A trend validity flag is generated when the co-degradation condition is met, indicating the continuous validity of the current link degradation trend over time. The trend validity flag is a defined value, which can be defined as either valid or invalid, or represented by a binary value. When the consistency constraint determination result meets the co-degradation condition, the trend validity flag is set to valid; when the co-degradation condition is not met, the trend validity flag is set to invalid. To reflect "continuous validity," the trend validity flag can be implemented with a hold period. That is, once the trend validity flag is set to valid, if the co-degradation condition is still met within several subsequent observation periods, it remains valid; if the co-degradation condition is not met for several consecutive observation periods, it is reverted to invalid. In this way, the trend validity flag not only reflects whether co-degradation has occurred but also whether the degradation trend is persistent.

[0030] Under the constraint of a valid trend marker, the potential impact of link degradation is quantitatively assessed based on the change amplitude parameter, generating a risk intensity parameter associated with the valid trend marker. "Under the constraint of a valid trend marker" means that the risk intensity parameter is calculated and updated only when the valid trend marker is valid; if the valid trend marker is invalid, the risk intensity parameter can be set to zero, retain the previous valid calculated value, or be reduced according to a preset attenuation rule. The risk intensity parameter is a continuous value characterizing the degree of degradation; its calculation should explicitly depend on the change amplitude parameter and be able to distinguish between minor and severe degradation. One feasible approach is to combine the change amplitude parameters of at least two categories of indicators that meet the conditions for coordinated degradation to obtain a comprehensive intensity value. For example, when the signal quality degradation is 0.12, the transmission error increase is 0.25, and the service latency change increase is 0.18, the magnitude parameters of two or three of these parameters can be summed or weighted to obtain the risk intensity parameter. The weights can be preset and fixed. For example, weights of 0.4, 0.4, and 0.2 can be assigned to signal quality, transmission errors, and service latency variations, respectively, resulting in a risk intensity parameter of 0.4×0.12 + 0.4×0.25 + 0.2×0.18 = 0.048 + 0.100 + 0.036 = 0.184. A larger value indicates a stronger impact from link degradation. To avoid biases caused by different units of measurement, it is recommended that all the above magnitude parameters be normalized using the same method before calculation to ensure that the combined risk intensity parameter is comparable within a uniform numerical range.

[0031] A more detailed example is given below. Assume a sampling period of 100 milliseconds, with five consecutive observation periods forming a time window. The terminal obtains signal-to-noise ratio (SNR) sequences of 20, 19, 18, 17, and 16 dB within these five periods; block error rate (BER) sequences of 0.01, 0.02, 0.03, 0.04, and 0.05; and delay jitter sequences of 5, 7, 9, 12, and 15 milliseconds. According to the direction determination rule, the SNR direction is continuously decreasing, the BER direction is continuously increasing, and the delay jitter direction is continuously increasing. Therefore, the co-degradation condition of "signal quality deterioration and transmission error increase" is satisfied and continues to be satisfied within this window. Thus, the trend validity marker is set to valid and remains valid. Further quantization is performed based on amplitude parameters. For example, by calculating the relative decrease in SNR, the relative increase in BER, and the relative increase in delay jitter separately and combining them with weights, a risk intensity parameter greater than zero that increases with increasing degradation can be obtained. Ultimately, the risk intensity parameter and the trend validity marker together constitute the basis for forward-looking risk assessment. The trend validity marker is used to answer "whether there is a continuous degradation trend", and the risk intensity parameter is used to answer "how severe is the degradation trend". The combination of the two can provide a clear, comparable and repeatable triggering basis for whether to initiate the radio frequency and access process of the second communication mode.

[0032] Furthermore, the process of performing consistency constraint determination on the stability trend description set, determining whether the change direction identifiers of at least two types of stability information satisfy a preset collaborative degradation condition within the same time window, and generating a trend validity marker when the collaborative degradation condition is satisfied, to indicate the continuous validity of the current link degradation trend in the time dimension, includes: in the communication terminal, based on the stability trend description set, extracting the change direction identifier sequence of multiple types of stability information within the same time window according to a preset time window length, and organizing the change direction identifier sequence into a direction combination state set to describe the consistency of changes of multiple indicators within the time window; based on the direction combination state... The system determines whether at least two types of stability information change direction identifiers are simultaneously in a predefined set of degradation directions within a given time window. If the determination is successful, a window degradation consistency result is generated to characterize the consistency status of multiple index degradation directions within that time window. Correlation analysis is performed on the window degradation consistency results corresponding to multiple consecutive time windows to determine whether the window degradation consistency results remain continuously valid in adjacent time windows. If the continuity condition is met, a trend continuity determination result is generated to characterize the persistence of link degradation over time. Under the condition that the trend continuity determination result is valid, a trend validity marker corresponding to the trend continuity determination result is generated.

[0033] In this embodiment, the stability trend description set is derived from the sampling, alignment, and trend calculation results of stability information. It includes at least the change direction identifiers and change magnitude parameters of three types of stability information—signal quality, transmission errors, and service delay changes—over multiple consecutive observation periods. The change direction identifier is a discrete value used to describe whether a certain stability information is increasing, decreasing, or remaining essentially unchanged between adjacent observation periods. To avoid ambiguity, the change direction identifier can be defined as a three-valued or two-valued discrete quantity in implementation. For example, increasing can be defined as +1, decreasing as -1, and remaining essentially unchanged as 0. Alternatively, when only focusing on the degradation and non-degradation directions, degradation can be defined as 1 and non-degradation as 0. Regardless of the encoding method used, consistency throughout the system is sufficient. The object processed in this embodiment is the change direction identifier sequence formed by each type of stability information over multiple observation periods. These sequences are arranged in chronological order and can be indexed to the changes of different indicators within the same time range.

[0034] The time window length refers to the coverage area of ​​the window used to perform consistency constraint judgment. It can be expressed as the number of observation periods or as an absolute time length. For example, if the observation period is 100 milliseconds, the time window length can be set to five observation periods, then the time window covers the sequence of change direction indicators within a range of 500 milliseconds. This application emphasizes coordinated degradation "within the same time window" to ensure that the degradation directions of different indicators do not appear accidentally at different time points, but rather appear simultaneously or highly overlap within the same time period. For ease of implementation, the communication terminal can adopt a sliding window method: after each observation period, the window slides forward by one observation period, forming an overlap between adjacent time windows; or it can adopt a segmented window method: windows do not overlap. Sliding windows are more conducive to continuity judgment, while segmented windows are more convenient for calculation. This application does not limit the specific choice.

[0035] When a communication terminal extracts the change direction identifier sequences of multiple types of stability information within the same time window according to a preset time window length, the terminal needs to specify the start and end indices corresponding to the window and extract the same index range from the direction sequence of each type of stability information to obtain the direction sub-sequence within the window. Taking three types of stability information as an example, three direction sub-sequences will be obtained within a time window, corresponding to the signal quality direction sub-sequence, transmission error direction sub-sequence, and service delay change direction sub-sequence, respectively. Subsequently, these change direction identifier sub-sequences are organized into a direction combination state set. The so-called direction combination state set refers to using a unified data structure to describe the combination relationship of the change directions of multiple indicators within the time window, so that subsequent judgments can be made directly on this data structure without repeatedly accessing the original sequence. An implementable organization method is to use the observation period as the smallest unit, forming a "direction combination state" at each observation period position within the window. This state contains the direction identifiers of the three types of indicators at the same time. For example, a triple (signal quality direction_j, transmission error direction_j, delay change direction_j) is formed at the j-th position within the window, and the set of triples at all positions within the window constitutes the direction combination state set. Another possible implementation is to treat the directional subsequence of each type of indicator within the window as a vector and form a matrix. The rows of the matrix correspond to the indicator type, and the columns correspond to the observation period positions within the window. This can also be regarded as a set of directional combination states. Regardless of whether a triplet list or matrix form is used, the purpose is to provide direct data support for the judgment of whether the directions of multiple indicators within the same window are co-degrading.

[0036] When determining whether at least two types of stability information change direction identifiers simultaneously fall within a predefined degradation direction set within a time window based on the direction combination state set, it is necessary to first clarify what the predefined degradation direction set is. The degradation direction set is a discrete set used to indicate in which direction a certain type of stability information is considered "degraded." Since the meaning of degradation direction differs for different indicators, the degradation direction set should be defined separately for each indicator type. For signal quality, a decrease usually indicates degradation, so its degradation direction set can be defined as {decreasing} or {-1}; for transmission errors, an increase usually indicates degradation, so its degradation direction set can be defined as {increasing} or {+1}; for changes in service latency, an increase or increased jitter usually indicates degradation, so its degradation direction set can be defined as {increasing} or {+1}. In implementation, the communication terminal can establish a degradation direction mapping table to clarify the degradation direction set for each type of indicator. In this way, the direction triplet at each position in the direction combination state set can be judged one by one: if at the same position, the direction identifiers of at least two types of indicators fall into their respective degenerate direction sets, then a "co-degenerate event" is considered to have occurred at that position. Since this embodiment requires judging "whether there are at least two types of stability information change direction identifiers simultaneously in the degenerate direction set within the time window", this means that as long as there is at least one co-degenerate event within the window, the judgment is considered to be valid. To further enhance stability, more stringent conditions can also be introduced in the implementation, such as requiring that the number of times the co-degenerate event occurs within the window is not less than a preset threshold, or that a number of co-degenerate events occur consecutively within the window.

[0037] When a determination is valid, a window degradation consistency result is generated to characterize the consistency status of the degradation direction of multiple indicators within that time window. The window degradation consistency result should be a clear and transferable data object to facilitate subsequent cross-window continuity analysis. The simplest and clearest way is to define it as a binary result, for example, 1 for consistency validity and 0 for non-consistency; it can also be defined as a multi-valued result, for example, in addition to validity and non-consistency, it can also include levels such as "weakly valid" and "strongly valid".

[0038] Correlation analysis of window degradation consistency results corresponding to multiple consecutive time windows means that the communication terminal focuses not only on whether the consistency of a single window is valid, but also on whether the consistency continues to appear between adjacent windows, thereby determining whether the degradation trend has temporal continuity. Adjacent time windows refer to two windows that are immediately adjacent in a window sequence. If a sliding window is used, adjacent windows typically overlap for most of the observation period; if a segmented window is used, adjacent windows do not overlap but are contiguous in time. The implementation method of correlation analysis can be very explicit: checking whether there are several consecutive windows in the consistency result sequence where the consistency result is valid. For example, the consecutive validity condition can be set to "two adjacent windows are consecutively valid," meaning the consistency result is 1 in both window k and window k+1; or it can be set to a stricter "L consecutive windows are valid," meaning the consistency result is 1 from window k to window k+L-1. The setting of the consecutive validity condition is related to the sensitivity of the terminal service. More sensitive services can set a stricter number of consecutive windows to reduce false triggers, while services that emphasize rapid response can set a smaller number of consecutive windows to improve sensitivity. In any case, this condition must be explicitly defined as a specific window number threshold in the implementation to meet the clarity requirement.

[0039] A trend continuity determination result is generated when the continuity condition is met, used to characterize the persistence of link degradation over time. The trend continuity determination result should also be a clearly transferable result object, preferably defined as binary: 1 for success and 0 for failure. Its calculation logic should also be clear: when the latest set of window degradation consistency results meets the continuity condition, the trend continuity determination result is set to success; otherwise, it is set to failure. This result can be updated once with each new window generation, enabling the system to determine in real time whether a degradation trend has formed and continues.

[0040] Under the condition that the trend continuity determination result is true, a trend validity flag corresponding to the trend continuity determination result is generated. The trend validity flag is used to indicate the continuity validity of the current link degradation trend in the time dimension. It is an important gating condition for subsequent risk intensity parameter calculation and pre-activation triggering of the second communication mode. To avoid ambiguity, the trend validity flag is also recommended to be defined as a binary flag, with 1 for validity and 0 for invalidity. Its setting condition is explicitly that the trend continuity determination result is true, and its reset condition can be explicitly defined as the trend continuity determination result being false for a preset number of times or for a preset window number of times. This embodiment also provides a clear failure mechanism to ensure the stability and operability of the system. For example, when the window degradation consistency result of two consecutive windows is 0, the trend validity flag is set to 0, thereby avoiding the trend validity flag being mistakenly maintained during short-term recovery.

[0041] To facilitate direct understanding and implementation by those skilled in the art, a specific and calculable example is given below. Assume the observation period is 100 milliseconds, the time window length is five observation periods, and a sliding window method is used, updating the window after each observation period. Assume that in ten consecutive observation periods, the sequence of signal quality change directions is [-1, -1, -1, -1, -1, 0, -1, -1, -1, -1], the sequence of transmission error change directions is [+1, +1, +1, 0, +1, +1, 0, +1, +1, +1], and the sequence of service delay change directions is [+1, 0, +1, +1, +1, 0, +1, +1, 0, +1]. The degradation direction set is defined as follows: the degradation direction of signal quality is -1, the degradation direction of transmission errors is +1, and the degradation direction of service delay changes is +1. For the first time window covering observation periods 1 to 5, checking whether at least two types of indicators are in the degradation direction at each location reveals that period 1 satisfies signal quality degradation, increased transmission errors, and increased latency; period 2 satisfies signal quality degradation and increased transmission errors; period 3 satisfies all three simultaneously; period 4 satisfies signal quality degradation and increased latency; and period 5 satisfies all three simultaneously. Therefore, a co-degradation event exists within this window, and the window degradation consistency result is recorded as 1. The second time window covering observation periods 2 to 6 similarly shows co-degradation events in periods 2, 3, and 5. Although all three are non-degradable in period 6, a co-degradation event still exists within the window, so the window degradation consistency result remains 1. If the continuity condition is set to two adjacent windows both being 1, then since window 1 and window 2 have already met the continuity condition, the trend continuity determination result is 1, and therefore the trend validity marker is generated and set to 1. If two consecutive window degradation consistency results are 0 in subsequent windows, the trend continuity determination result becomes 0, and the trend validity marker can be reset to 0. This example demonstrates that the effective indication of a trend is not triggered by occasional fluctuations within a single observation period, but rather by the combined effect of intra-window co-degradation and inter-window continuity, thus providing a more reliable indication of the continuous effectiveness of the link degradation trend.

[0042] Step S102: When the forward-looking risk assessment criteria meet the preset conditions, without terminating the service transmission of the first communication mode, the radio frequency and access process of the second communication mode is initiated, so that the second communication mode enters an available state that can carry service data in parallel.

[0043] In this invention, step S102 is a key follow-up step performed based on the forward-looking risk assessment basis formed in step S101. Its purpose is to create conditions in advance for possible communication mode adjustments when the first communication mode can still maintain service transmission, thereby avoiding the risk of service interruption caused by "interruption first, access later" in the traditional handover process.

[0044] First, "when the forward-looking risk assessment criteria meet the preset conditions" means that the communication terminal does not activate the second communication mode at all times, but only executes this step when the forward-looking risk assessment criteria formed in step S101 reach or exceed the preset trigger conditions. The preset conditions can be one or more risk thresholds used to determine whether the probability of significant link degradation in the first communication mode within a future period reaches a level requiring early intervention. For example, it can be preset that when the comprehensive risk index corresponding to the link degradation trend is higher than the threshold for multiple consecutive assessment periods, or shows a continuous upward trend within a limited time window, the preset conditions are considered met. Those skilled in the art can reasonably configure these preset conditions according to the communication standard, service type, or terminal performance without affecting the implementation of step S102 of this invention.

[0045] After the above conditions are met, "without terminating the service transmission of the first communication mode" is one of the core limitations of this step. This means that when the communication terminal performs operations related to the second communication mode, it does not interrupt, release, or rebuild the service data currently being transmitted through the first communication mode. Specifically, the data bearer path, session state, and service processing flow of the first communication mode remain unchanged, and all operations for the second communication mode are completed in the background or auxiliary execution path as parallel preparation processes. This limitation ensures that step S102 itself will not negatively impact existing services and is a crucial prerequisite for achieving seamless switching later.

[0046] "The RF and access procedures for initiating the second communication mode" refers to the communication terminal sequentially completing the underlying and access layer preparation operations required for normal communication in the second communication mode. The RF procedure refers to the process by which the RF unit corresponding to the second communication mode switches from a non-operating or low-power state to an operating state. This process may include RF module power-on, local oscillator stabilization, frequency band configuration, power parameter setting, and necessary RF calibration operations. The access procedure refers to the process by which the communication terminal establishes a logical connection with the corresponding network-side equipment according to the specifications of the communication system to which the second communication mode belongs. This includes operations such as synchronization signal detection, system information acquisition, identity authentication, resource allocation, and bearer establishment. The specific implementation of the above RF and access procedures may vary depending on the second communication mode. For example, when the second communication mode is cellular communication, its access procedure may include cell search, random access, and bearer establishment; when the second communication mode is wireless LAN communication, its access procedure may include scanning, association, and authentication. This invention does not limit the specific type of the second communication mode, as long as it can complete RF activation and network access.

[0047] After completing the aforementioned radio frequency and access procedures, the phrase "entering a state where the second communication mode can carry service data in parallel" is a clear definition of the second communication mode's state. This "state where the second communication mode can carry service data in parallel" means that the second communication mode has not only completed connections at the physical and access layers, but also logically possesses the ability to carry service data simultaneously with the first communication mode. In other words, the second communication mode has been allocated communication resources available for service transmission, and its data transmission path is in a schedulable and usable state. It is important to emphasize that this state differs from a standby state where registration or readiness has only been completed; rather, it signifies that the second communication mode is technically ready to immediately participate in service data transmission, but has not yet been designated as the primary bearer communication mode.

[0048] In a specific implementation example, after the communication terminal detects that the forward-looking risk assessment criteria for the first communication mode meet preset conditions, it can activate the radio frequency module of the second communication mode in the background, while continuing to send and receive service data to and from the network side through the first communication mode. Once the second communication mode completes access and successfully establishes at least one bearer channel usable for data transmission, it can be determined that the second communication mode has entered a usable state capable of carrying service data in parallel. At this point, the communication terminal does not immediately switch the service data to the second communication mode, but keeps both communication modes available simultaneously, allowing subsequent steps to select based on comprehensive conditions.

[0049] In this way, step S102 completes the necessary technical preparations for the second communication mode in advance without interfering with the existing service transmission, so that the communication terminal can transition from a single communication mode operation state to a dual-mode parallel availability state, laying the foundation for the determination of the main bearer communication mode and the smooth implementation of data migration in subsequent steps.

[0050] Furthermore, when the forward-looking risk assessment criteria meet preset conditions, and without terminating the service transmission of the first communication mode, the radio frequency and access process of the second communication mode is initiated, enabling the second communication mode to enter a usable state capable of carrying service data in parallel. This includes: in the communication terminal, based on the trend validity marker and risk intensity parameter in the forward-looking risk assessment criteria, determining whether the second communication mode has the qualification to trigger early intervention in service carrying, and generating pre-activation indication information for the second communication mode when the qualification is determined to be met, to identify the initiation conditions for the second communication mode to enter the pre-activation process; under the constraint of the pre-activation indication information, performing a limited power start-up operation on the radio frequency unit of the second communication mode, and completing the initialization of the basic radio frequency parameters of the second communication mode while keeping the radio frequency configuration of the first communication mode unchanged, generating a radio frequency pre-activation status marker to characterize the working ready state of the radio frequency unit of the second communication mode; based on the radio frequency pre-activation status marker, triggering the access preparation process of the second communication mode, and completing the access verification and resource negotiation between the second communication mode and the network side without establishing a service data carrying channel, generating access availability status information to characterize the second communication mode's data carrying conditions; after the access availability status information is generated, marking the second communication mode as a parallel usable communication mode.

[0051] In this embodiment, the content describes in detail how, when the forward-looking risk assessment criteria meet preset conditions, the second communication mode can enter a usable state capable of carrying service data in parallel without interrupting the service transmission of the first communication mode. The core purpose of this process is to avoid the service interruption risks caused by "disconnecting before reconnecting" or "complete switching" in traditional communication systems. Instead, it uses a controlled and gradual approach to enable the second communication mode to complete the necessary preparations in advance while the first communication mode is still stably carrying services, thereby providing conditions to ensure the selection of the subsequent primary bearer communication mode and data migration.

[0052] In this process, the communication terminal first determines whether the second communication mode is qualified to trigger early intervention in service carrying based on the established forward-looking risk assessment criteria. The forward-looking risk assessment criteria include at least a trend validity marker and a risk intensity parameter. The trend validity marker indicates whether the current link degradation trend is determined to be persistent over time, and the risk intensity parameter quantifies the potential impact of this degradation trend on service transmission. The communication terminal can pre-set a set of explicit triggering rules. For example, the second communication mode is considered qualified to trigger early intervention in service carrying only when the trend validity marker is valid and the risk intensity parameter exceeds a preset threshold. This threshold can be set according to the service type, terminal capabilities, or system policies. For example, when the risk intensity parameter ranges from 0 to 1, the threshold can be set to 0.5 to distinguish between minor degradation and degradation requiring early intervention. If the determination result meets the triggering conditions, the communication terminal generates a pre-activation indication message for the second communication mode to clearly identify the start conditions for the second communication mode to enter the pre-activation process. If the triggering conditions are not met, the second communication mode remains inactive, thereby avoiding unnecessary resource consumption.

[0053] After generating the pre-activation indication information, the communication terminal, under the constraints of this indication information, performs a power-limited startup operation on the radio frequency unit of the second communication mode. Power-limited startup means that when starting the radio frequency unit of the second communication mode, it does not operate at the maximum or rated power required for normal service carrying, but rather starts at a preset power level lower than the normal service power. This ensures that the radio frequency unit of the second communication mode enters a controllable working state without significantly increasing energy consumption or interfering with the radio frequency operation of the first communication mode. During this process, the communication terminal explicitly maintains the radio frequency configuration of the first communication mode unchanged, including its operating frequency band, transmit power, modulation method, and other key parameters, ensuring that the first communication mode continues to stably carry current service data. Simultaneously, the communication terminal completes the initialization of the basic radio frequency parameters of the second communication mode. This initialization includes at least frequency band selection, radio frequency channel configuration, and basic synchronization parameter settings, enabling the radio frequency unit of the second communication mode to meet the necessary conditions for subsequent access preparation. After completing the above operations, the communication terminal generates a radio frequency pre-activation status flag to indicate that the radio frequency unit of the second communication mode is in a state of being ready for operation but not yet undertaking service carrying.

[0054] After the radio frequency pre-activation status flag is generated, the communication terminal further triggers the access preparation process for the second communication mode based on this flag. The access preparation process refers to enabling the second communication mode to complete necessary access verification and resource negotiation operations with the network side without establishing an actual service data bearer channel. Specifically, the communication terminal can send access requests or capability indication information to the network side through the second communication mode to complete processes such as identity verification, access license confirmation, and basic resource negotiation, but without requesting or allocating bearer resources for service data transmission from the network side, thus avoiding impact on existing service processes. In this way, the communication terminal can confirm whether the second communication mode has normal access conditions in the current network environment and obtain information on the bearer capabilities that the network side can provide in advance. After access verification and resource negotiation are completed, the communication terminal generates access availability status information to clearly indicate that the second communication mode logically has the conditions to bear service data and can be put into use only after subsequent primary bearer selection or data migration triggering.

[0055] After the access availability status information is generated, the communication terminal marks the second communication mode as a parallel available communication mode. A parallel available communication mode means that this mode has completed the necessary initialization and verification at the physical layer, access layer, and protocol preparation levels, and can participate in the carrying or migration of service data at any time without affecting the normal operation of the first communication mode. At this time, the first communication mode continues to operate as the current service carrying path, while the second communication mode is in a standby state. Its parallel availability identifier will be output to the subsequent primary bearer communication mode selection and data migration strategy generation process as an important input condition for decision-making.

[0056] Through the above process, the communication terminal can complete the radio frequency and access preparation for the second communication mode in advance, before service interruption occurs, even if a continuous degradation risk is detected in the link. This allows it to enter a parallel available state with low interference and low power consumption. This progressive pre-activation and access preparation mechanism gives the dual-mode communication system greater foresight and flexibility in the face of link degradation, providing a stable, controllable, and implementable technical foundation for subsequent primary bearer mode switching and service data migration, thereby effectively ensuring the continuity of service transmission.

[0057] Step S103: When both the first communication mode and the second communication mode are available, the selection result of the primary bearer communication mode and the corresponding data migration strategy are generated by combining the link degradation trend and the channel conditions and network load of the two communication modes.

[0058] In this invention, step S103 is a decision-making step performed based on steps S101 and S102. Its technical function is to: when both the first and second communication modes are simultaneously available, through comprehensive analysis of multi-dimensional communication conditions, clearly determine which communication mode should undertake the primary task of carrying subsequent business data, and formulate a matching data migration strategy accordingly. This provides a clear and executable control basis for subsequent smooth migration and seamless switching. This step not only determines the master-slave relationship of the communication modes but also directly affects service continuity, transmission efficiency, and terminal resource utilization.

[0059] First, it's necessary to explain the meaning of "both the first and second communication modes are simultaneously available." This state means that after step S102, the first communication mode retains its original service carrying capacity, and its radio frequency, link, and bearer resources are not released; simultaneously, the second communication mode has completed the radio frequency activation and access process and established a bearer channel that can be used for service data transmission. Both communication modes are technically capable of actually participating in the transmission scheduling of service data. In this state, the communication terminal has the conditions to select, allocate, or migrate service data between the two communication modes.

[0060] Based on this, step S103 requires "combining the link degradation trend with the channel conditions and network load corresponding to the two communication modes." The link degradation trend refers to the direction and degree of change reflected in the forward-looking risk assessment criteria formed based on stability information in step S101, used to characterize the risk level of potential performance degradation of the first communication mode in the future. This trend can be reflected in the magnitude, growth rate, or duration of risk indicators, such as a continuous increase in risk indicators or approaching the upper limit of a threshold. Channel conditions refer to the currently available physical or logical transmission conditions for each communication mode, including but not limited to parameters such as signal-to-noise ratio, available bandwidth, interference level, and link stability. These parameters can be directly obtained through the communication protocol stack or RF measurement module. Network load refers to the current resource occupancy level on the network side corresponding to each communication mode, such as scheduling queue length, resource block utilization, number of access users, or congestion indication information, used to reflect the ability of the communication mode to carry new service data at the current moment.

[0061] "Generating the selection result for indicating the primary bearer communication mode" means that, after considering the above factors, the communication terminal clearly determines which communication mode will be the primary data bearer path for a subsequent period of time. The "primary bearer communication mode" refers to the communication mode that is preferentially used to carry most or all of the service data when both modes are available in parallel, while the other communication mode is in an auxiliary, alternative, or transitional state. This selection result can be a clear determination indicating whether the first or second communication mode is the primary bearer communication mode, and can be recorded and transmitted internally by the terminal in the form of flag bits, status variables, or control commands.

[0062] In practical implementation, the communication terminal can quantify the link degradation trend, channel conditions, and network load separately, and perform a comprehensive evaluation according to preset rules. For example, a comprehensive bearer evaluation value can be calculated for each communication mode. This evaluation value consists of multiple components, one reflecting link stability risk, another reflecting current channel quality, and the third reflecting network load level. For example, for the first communication mode, its comprehensive bearer evaluation value can be composed of "link degradation risk weight × risk index + channel condition weight × channel quality score + load weight × load score"; for the second communication mode, an evaluation value with the same structure can be calculated based on its corresponding channel conditions and network load. When the comprehensive bearer evaluation value of the second communication mode is better than that of the first communication mode, or when the degradation risk of the first communication mode exceeds a preset safety range, the second communication mode can be determined as the primary bearer communication mode. The above calculation method is only an example, and this invention does not limit the specific weight settings or calculation formulas, as long as the selection of the primary bearer communication mode can be completed based on the link degradation trend, channel conditions, and network load.

[0063] Simultaneously, while determining the primary bearer communication mode, it is also necessary to "generate a corresponding data migration strategy." The data migration strategy refers to a control scheme used to guide the transfer of business data from the original bearer path to the primary bearer communication mode. Its content includes at least information such as the timing of data migration, migration ratio, or migration pace. The "migration ratio" refers to the proportion of business data carried by each communication mode within a certain migration period; the "migration pace" refers to the speed or phased division of data transfer from the original communication mode to the primary bearer communication mode. For example, in the initial stage, only a small amount of non-critical business data or newly generated data can be allocated to the primary bearer communication mode. After confirming its stable operation, the proportion of data transmitted through the primary bearer communication mode can be gradually increased until it carries all business data.

[0064] In a specific implementation example, if the link degradation trend of the first communication mode shows that its risk indicators are continuously increasing but have not yet reached an unavailable state, while the current channel quality of the second communication mode is good and the network load is low, then the communication terminal can determine the second communication mode as the primary bearer communication mode and generate a phased data migration strategy. For example, in the first migration cycle, 30% of the new service data can be transmitted through the second communication mode, and in subsequent migration cycles, this can be gradually increased to 60%, 90%, until all service data is migrated. The above migration strategy can be dynamically adjusted based on terminal capabilities, service type, or real-time monitoring results.

[0065] In this way, step S103 not only completes the clear selection of the main bearer communication mode, but also provides a specific and executable strategy basis for the gradual migration of service data in subsequent steps, enabling the communication terminal to achieve orderly and controllable communication bearer reconstruction in a dual-mode parallel state.

[0066] Furthermore, when both the first and second communication modes are simultaneously available, the process of generating a result indicating the selection of the primary bearer communication mode and a corresponding data migration strategy, based on the link degradation trend and the channel conditions and network load corresponding to the two communication modes, includes: in the communication terminal, based on the judgment result representing the link degradation trend in the forward-looking risk judgment criteria, extracting the link risk reference parameters corresponding to the first and second communication modes at the current moment, and associating the link risk reference parameters with their respective communication mode identifiers to form a mode risk mapping set describing the degradation sensitivity of different communication modes; based on the mode risk mapping set, obtaining the real-time channel condition parameters and network load parameters corresponding to the first and second communication modes, and within the same evaluation period, transferring the channel condition parameters... The network load parameters and corresponding link risk reference parameters are combined to generate a mode bearer assessment state set that reflects the comprehensive bearer adaptability of each communication mode within the current assessment period. The main bearer determination rule is applied to the mode bearer assessment state set to compare the comprehensive bearer adaptability of different communication modes. When the preset main bearer switching conditions are met, the target main bearer communication mode is determined, and a bearer reconfiguration indication result corresponding to the target main bearer communication mode is generated to indicate the direction of the main bearer role change. Under the constraint of the bearer reconfiguration indication result, a data migration strategy matching the target main bearer communication mode is generated based on the bearer capability difference between the non-main bearer communication mode and the target main bearer communication mode. The data migration strategy includes at least data migration stage division information and data migration ratio information corresponding to each stage.

[0067] In this embodiment, the content describes in detail how a communication terminal determines the primary bearer communication mode and generates a corresponding data migration strategy by comprehensively considering link degradation trends, channel conditions, and network load when both the first and second communication modes are simultaneously available. The design goal of this process is to avoid switching communication modes based solely on a single link quality or instantaneous indicator. Instead, by introducing degradation trend perception and bearer capacity assessment, the determination of the primary bearer communication mode is forward-looking, stable, and feasible, thereby providing a clear basis for the smooth migration of subsequent service data.

[0068] In this process, the communication terminal first calculates the corresponding link risk reference parameters for the first and second communication modes based on the established forward-looking risk assessment criteria. These link risk reference parameters quantify the degree of risk a given communication mode faces due to link degradation trends when carrying services in the current network environment. They are calculable numerical parameters, not abstract evaluation results. To ensure the comparability and feasibility of the calculation results, the link risk reference parameters are jointly determined by at least two known and obtainable assessment quantities: a trend validity marker and a risk intensity parameter.

[0069] The trend validity flag indicates whether the link degradation trend is considered persistent over time, and its value can be explicitly defined as valid or invalid. The risk intensity parameter quantifies the potential impact of the link degradation trend on service transmission, and its value range can be pre-defined as a continuous numerical range, such as a normalized value between 0 and 1 or other real numbers within a preset range. When calculating the link risk reference parameter, the communication terminal first determines the trend validity flag status of the corresponding communication mode. When the trend validity flag is invalid, the link risk reference parameter for that communication mode is directly set to a preset low-risk benchmark value to indicate that there is currently no sustainable degradation risk. When the trend validity flag is valid, the link risk reference parameter is further quantified based on the risk intensity parameter.

[0070] In one feasible approach, the communication terminal can define the link risk reference parameter as a functional mapping result of the trend validity marker and the risk intensity parameter. For example, when the trend validity marker is valid, the link risk reference parameter is set to a value positively correlated with the risk intensity parameter; that is, the larger the risk intensity parameter, the larger the link risk reference parameter. When the trend validity marker is invalid, the link risk reference parameter is limited to a fixed low value or zero. For instance, when the trend validity marker of a certain communication mode is valid and its corresponding risk intensity parameter is 0.8, the communication terminal can directly set the link risk reference parameter of that communication mode to 0.8. When the trend validity marker of another communication mode is invalid, even if its instantaneous risk intensity parameter fluctuates, its link risk reference parameter can be set to a preset low-risk value such as 0 or 0.1, thereby explicitly distinguishing between "trend degradation risk" and "non-persistent fluctuation" in subsequent decisions.

[0071] In another possible implementation, to further enhance distinguishability, the communication terminal can also introduce amplification or suppression factors to adjust the risk intensity parameter when the trend is marked as valid. For example, the link risk reference parameter can be calculated as the product of the risk intensity parameter and the trend duration weight, reflecting that the longer the degradation trend lasts, the greater its adverse impact on the bearer decision. Regardless of the specific mapping method used, the calculation of the link risk reference parameter should explicitly depend on the trend validity marker and the risk intensity parameter, and its value should be directly usable for risk comparison between different communication modes.

[0072] After completing the above calculations, the communication terminal binds and stores the obtained link risk reference parameters with the corresponding communication mode identifiers, forming a mode risk mapping set. This mode risk mapping set uses the communication mode as an index and the link risk reference parameters as mapping values. It is used in subsequent steps to directly compare the differences in risk dimensions of different communication modes, thereby providing clear and quantifiable input basis for the selection of the primary bearer communication mode and the generation of data migration strategies.

[0073] After obtaining the mode risk mapping set, the communication terminal further acquires the real-time channel condition parameters and network load parameters corresponding to the first and second communication modes, respectively. The channel condition parameters describe the transmission environment of the communication mode on the current wireless or wired channel, and may include indicators reflecting the physical layer or link layer status, such as received signal strength, signal-to-noise ratio, available channel bandwidth, and modulation / coding scheme adaptation. The network load parameters describe the resource occupancy and congestion of the communication mode in the current network, such as the current number of connections, queue length, scheduling delay, or resource utilization. To ensure the comparability of the evaluation results, the communication terminal acquires the aforementioned channel condition parameters and network load parameters within the same evaluation period and combines them with the aforementioned link risk reference parameters. This combination processing refers to mapping the three types of parameters into an evaluation result characterizing the overall carrying capacity adaptability of the communication mode according to preset calculation rules. For example, the channel condition parameters can be transformed into a positive carrying capacity indicator, the network load parameters into a negative constraint indicator, and the link risk reference parameters can be used as adjustment factors reflecting future degradation possibilities. A comprehensive carrying capacity adaptability value can be generated through weighted summation or segmented mapping. For example, if the first communication mode has a high signal-to-noise ratio and low network load in the current evaluation period, but its link risk reference parameter is high, its overall bearer adaptability value will be appropriately reduced due to risk factors. Conversely, even if the channel conditions for the second communication mode are slightly worse, if the network load is lighter and the link risk reference parameter is lower, its overall bearer adaptability value may be higher than that of the first communication mode. Through this method, the communication terminal forms a mode bearer evaluation state set, which clearly reflects whether each communication mode is more suitable to assume the primary bearer role in the current evaluation period.

[0074] After obtaining the mode bearer assessment state set, the communication terminal executes the primary bearer determination rule to compare the comprehensive bearer adaptability of different communication modes. The primary bearer determination rule is a pre-defined decision rule used to determine the primary bearer role among multiple communication modes. This rule can include a direct comparison of comprehensive bearer adaptability values, or it can include threshold judgments and priority constraints. For example, when the comprehensive bearer adaptability value of the second communication mode exceeds a preset difference threshold relative to the first communication mode, it is considered to meet the primary bearer switching condition, thus determining the second communication mode as the target primary bearer communication mode; if the difference does not reach the threshold, the original primary bearer mode remains unchanged. To avoid frequent switching, the primary bearer determination rule can also be combined with minimum hold time or switching suppression conditions, but regardless of the specific rule used, the result should clearly indicate the target primary bearer communication mode within the current assessment period. Simultaneously with determining the target primary bearer communication mode, the communication terminal generates a bearer reconfiguration indication result corresponding to that target primary bearer communication mode. This bearer reconfiguration indication result is used to clearly indicate the direction of the change in the primary bearer role, i.e., the transfer from the original primary bearer communication mode to the target primary bearer communication mode, providing a clear control basis for the subsequent data migration process.

[0075] Under the constraints of the bearer reconfiguration instruction, the communication terminal further generates a data migration strategy matching the target primary bearer communication mode based on the bearer capacity difference between the non-primary bearer communication mode and the target primary bearer communication mode. The bearer capacity difference mentioned here refers to the difference or level difference in the overall bearer adaptability of the two communication modes, which guides the pace and proportion of data migration. When the bearer capacity difference is large, it indicates that the target primary bearer communication mode is significantly better than the current non-primary bearer communication mode, and the data migration strategy can be designed with a faster migration pace. When the bearer capacity difference is small or there is still uncertainty, a more gradual data migration strategy can be adopted. To ensure business continuity and system stability, the data migration strategy includes at least the phase division information of data migration and the corresponding data migration proportion information for each phase. The phase division information refers to dividing the entire migration process into several consecutive phases, such as the initial phase, intermediate transition phase, and final completion phase; the corresponding data migration proportion information for each phase is used to clarify the proportion of business data migrated from the non-primary bearer communication mode to the target primary bearer communication mode in each phase. For example, in the initial stage, only a small amount of non-critical business data can be migrated. After confirming the stable operation of the target primary bearer communication mode, the migration ratio can be gradually increased in the intermediate stage, and finally, most or all of the business data can be migrated in the completion stage. This phased and proportional data migration method can effectively avoid network shocks or service interruptions caused by sudden migrations.

[0076] Through the above process, when both modes are available simultaneously, the communication terminal can not only scientifically determine the primary bearer communication mode based on the link degradation trend, channel conditions and network load, but also generate a data migration strategy that matches the capabilities of the primary bearer communication mode, so that the migration of subsequent service data has clear stages and controllability.

[0077] Step S104: Based on the selection result of the primary bearer communication mode and the data migration strategy, the service data is gradually transferred to the primary bearer communication mode for carrying, and the consistency of session identifier, transmission sequence and retransmission control status is maintained synchronously during the transfer process to achieve continuous service transmission.

[0078] In this invention, step S104 is a core implementation step performed after the primary bearer communication mode and corresponding data migration strategy have been determined in step S103. Its purpose is to smoothly and orderly transition service data from the original bearer path to the primary bearer communication mode, while ensuring that upper-layer services are unaware of the communication mode change throughout the migration process, thereby truly achieving continuous service transmission. This step involves not only adjusting the data forwarding path but also maintaining the consistency of session states across different communication modes.

[0079] First, "based on the selection result of the primary bearer communication mode and the data migration strategy" means that the communication terminal strictly follows the control result generated in step S103 to perform the data migration operation. The selection result of the primary bearer communication mode clarifies which communication mode should bear the main data load at the current stage, while the data migration strategy clarifies the method, pace, and proportion of business data transfer between different communication modes. When performing this step, the communication terminal does not arbitrarily switch all business data to the primary bearer communication mode all at once, but rather implements it gradually according to the established strategy to avoid the impact of sudden load changes or momentary link instability on the service.

[0080] The "gradual transfer" in "gradually transferring business data to the primary bearer communication mode" refers to a continuous migration process in which the communication terminal, according to a data migration strategy, migrates business data from the original communication mode to the primary bearer communication mode in stages and proportions. Specifically, business data can include data packets currently being transmitted, newly generated data packets, or data queue content that has not yet been sent. The communication terminal can prioritize allocating newly generated business data or data with low latency sensitivity to the primary bearer communication mode, while continuing to transmit data already in progress through the original communication mode, thereby avoiding the risk of interruption or reordering of ongoing transmissions. As the migration process progresses, the communication terminal can gradually increase the proportion of data transmitted through the primary bearer communication mode until the primary bearer communication mode carries all business data.

[0081] In a specific implementation example, if the data migration strategy is set to complete the migration in three phases, then in the first phase, the communication terminal can allocate approximately one-third of the newly generated service data to the primary bearer communication mode, while the remaining service data continues to be transmitted through the original communication mode; in the second phase, the proportion of data transmitted through the primary bearer communication mode is increased to approximately two-thirds; in the third phase, all service data is switched to the primary bearer communication mode. The above proportions are merely examples, and this invention does not limit specific values. Those skilled in the art can dynamically adjust the migration proportions based on service type, terminal performance, or real-time monitoring results.

[0082] While data is being transferred gradually, "maintaining consistency in session identifiers, transmission sequences, and retransmission control states" is a key technical feature for achieving continuous service transmission in this step. Session identifiers are unique information used to identify a service session or connection, such as session ID, connection identifier, or equivalent parameters, ensuring that data from different communication modes can be identified as belonging to the same service session. Transmission sequences are the sequence numbers used during service data transmission, ensuring that the receiving end can reassemble data in the correct order and detect packet loss. Retransmission control states are control information used to manage data retransmission behavior, such as the current retransmission window size, the boundaries of acknowledged data, or records of data to be retransmitted.

[0083] In this invention, "synchronization to maintain consistency" does not mean simply copying the aforementioned state information. Rather, it means that during data migration, the communication terminal ensures that the session identifier, transmission sequence, and retransmission control state used by the primary bearer communication mode remain logically continuous with the original communication mode when it begins to carry service data. For example, if a service data stream has been sent to sequence number N in the original communication mode and the receiving end has acknowledged it to sequence number M, then when the primary bearer communication mode begins to carry this service data, it should continue to send data with a sequence number not less than N, and use the acknowledged state from the receiving end as the starting point for retransmission control, thereby avoiding problems such as duplicate transmission, data loss, or disordered sequence.

[0084] In one specific implementation, the communication terminal can maintain a local session state record for unified management of session identifiers, sequence progression, and retransmission control parameters under different communication modes. As service data gradually migrates to the primary bearer communication mode, the communication terminal synchronously maps this session state record to the corresponding protocol processing flow of the primary bearer communication mode, allowing the primary bearer communication mode to logically "inherit" the session state of the original communication mode. In this way, even if the actual data transmission path changes, the upper-layer services still perceive the same continuous session.

[0085] In the above manner, during the entire execution of step S104, the communication terminal can smoothly complete the transfer of business data from the original communication mode to the main bearer communication mode according to the data migration strategy, and can maintain the continuity and consistency of the session layer during the migration process, thereby avoiding service interruption, session reconstruction or data anomaly caused by changes in communication mode.

[0086] Furthermore, based on the selection result of the primary bearer communication mode and the data migration strategy, the service data is gradually transferred to the primary bearer communication mode for carrying, and the consistency of session identifier, transmission sequence, and retransmission control status is maintained synchronously during the transfer process to achieve continuous service transmission. This includes: in the communication terminal, determining the current migration stage of the service data based on the stage division information in the data migration strategy, and prioritizing the migration of the service data to be migrated according to the data migration ratio information corresponding to the migration stage, generating a service data migration queue corresponding to the current migration stage; based on the service data migration queue, extracting the session identifier, transmission sequence status, and retransmission control status corresponding to the service data to be migrated from the non-primary bearer communication mode, and organizing the session identifier, transmission sequence status, and retransmission control status into a session identity. A session state set is used to describe the transmission context of the service data to be migrated in the non-primary bearer communication mode. Under the constraints of the session synchronization state set, the service data in the service data migration queue is sent through the target primary bearer communication mode according to the data migration ratio. During the transmission process, the session context in the primary bearer communication mode is dynamically aligned and updated based on the session synchronization state set to ensure that the session identifier, transmission sequence status, and retransmission control status in the primary bearer communication mode are consistent with those in the non-primary bearer communication mode. After confirming that the service data of the corresponding migration stage in the service data migration queue has been effectively carried in the primary bearer communication mode, the migration stage status flag is updated, and the service data migration operation of the next migration stage is triggered based on the updated migration stage status flag, until the migration of all service data to the primary bearer communication mode is completed.

[0087] At the start of the migration, the communication terminal first determines the current migration stage of the business data based on the stage division information in the aforementioned data migration strategy. The migration stages described here are logical divisions of the entire data migration process in terms of time and proportion. Their purpose is to break down what might have been a momentary data bearer switch into multiple continuous and controllable migration stages. Each migration stage corresponds to a specific set of data migration proportion information, used to limit the proportion of business data that should be migrated from the non-primary bearer communication mode to the target primary bearer communication mode within that stage. For example, in the initial stage, the data migration proportion can be set to a low value, migrating only a small amount of business data with low latency and reliability requirements; the migration proportion can be gradually increased in the intermediate stages; and the migration of most or even all business data can be completed in the final stage. After determining the current migration stage, the communication terminal prioritizes the business data to be migrated based on the data migration proportion information corresponding to that stage, thereby generating a business data migration queue corresponding to the current migration stage. Migration priority allocation refers to sorting business data according to its importance, real-time requirements, or other preset rules, so that, given the limited migration proportion, data more suitable for the current stage is migrated first.

[0088] After forming the service data migration queue, the communication terminal needs to ensure the continuity of service sessions during the migration process. Therefore, it extracts session state information associated with the service data to be migrated from the non-primary bearer communication mode. Here, the session identifier refers to identification information used to uniquely identify a service session, such as a connection identifier, session number, or logical channel identifier; the transmission sequence state refers to sequence control information used to ensure orderly data transmission, such as the sequence number of currently sent or acknowledged data; and the retransmission control state refers to control information related to reliable transmission mechanisms, such as unacknowledged data markers, retransmission counts, or retransmission window positions. These state information collectively constitute the complete transmission context of service data in the non-primary bearer communication mode. The communication terminal organizes the session identifier, transmission sequence state, and retransmission control state into a unified session synchronization state set. This session synchronization state set is used to accurately describe the transmission progress and control state of the current service data to be migrated in the non-primary bearer communication mode, and is the basis for subsequently restoring and aligning the session context in the target primary bearer communication mode.

[0089] Under the constraints of the session synchronization state set, the communication terminal selects a corresponding proportion of service data from the service data migration queue according to the data migration ratio of the current migration stage, and sends it through the target primary bearer communication mode. During transmission, the service data is not simply repackaged and sent; instead, the session context in the target primary bearer communication mode is dynamically aligned and updated using the session synchronization state set. Specifically, the communication terminal establishes a corresponding session context for the service data to be migrated in the target primary bearer communication mode, sets the session identifier to be consistent with the original session, initializes the transmission sequence state to the same sequence position as in the non-primary bearer communication mode, and simultaneously sets the retransmission control state to the same state value as the original mode. Thus, when service data is sent through the target primary bearer communication mode, it is logically considered a continuation of the original session, rather than a new session, thereby avoiding data out-of-order or duplicate transmission problems caused by discontinuous sequence numbers or inconsistent retransmission states. As service data continues to be sent in the target primary bearer communication mode, the communication terminal can also update the session synchronization state set in real time based on the sending and acknowledgment status, ensuring that the session context in both communication modes remains consistent or aligned.

[0090] Once the communication terminal confirms that the service data belonging to the current migration stage in the service data migration queue has been effectively carried in the target primary bearer communication mode, the migration stage is considered complete. Effective carrying means that the corresponding service data has been successfully sent through the target primary bearer communication mode and entered the normal transmission process, and its session context is running stably in the target primary bearer communication mode. At this point, the communication terminal updates the migration stage status flag to indicate the completion status of the current migration stage, and triggers the service data migration operation for the next migration stage based on the updated migration stage status flag. In this way, the migration process progresses step by step between multiple migration stages, with each stage presupposing the completion of the previous stage, until all migration stages are completed sequentially, thereby achieving the migration of all service data to the target primary bearer communication mode.

[0091] Step S105: After confirming that the primary bearer communication mode has stably carried all service data, perform downgrading or release processing on communication resources that are not used as the primary bearer communication mode, thereby completing the seamless switching of dual-mode communication.

[0092] In this invention, step S105 is a convergence step performed after the migration of service data to the primary bearer communication mode has been completed in step S104. Its function is to systematically organize and reclaim the communication resources occupied during the dual-mode parallel phase, enabling the communication terminal to smoothly transition from the dual-mode parallel operation state to a stable operation state centered on the primary bearer communication mode. This ensures the completion of the entire dual-mode communication switching process while maintaining service continuity. This step not only relates to the rational utilization of system resources but also directly affects the communication stability and terminal power consumption performance after the switch is completed.

[0093] First, confirming that the primary bearer communication mode has stably carried all service data is a prerequisite for executing this step. "Stablely carrying all service data" here does not simply mean that the primary bearer communication mode has started carrying service data, but rather that after a certain observation period or confirmation process, it can be determined that all service data has been transmitted through the primary bearer communication mode without any abnormalities. Specifically, after the data migration is complete, the communication terminal can continuously monitor the operating status of the primary bearer communication mode to confirm that there are no incompletely migrated data streams, unsynchronized session states, or abnormal retransmission behaviors. For example, within a preset confirmation time window, it can detect whether there is still service data being sent through non-primary bearer communication modes, or whether the transmission error rate and latency variations in the primary bearer communication mode are within acceptable ranges. When all the above conditions are met, it can be determined that the primary bearer communication mode has stably carried all service data.

[0094] After the above confirmation is completed, the core execution content of this step is to "downgrade or release communication resources that are not used as the primary bearer communication mode". The so-called "communication resources not used as the primary bearer communication mode" refers to the radio frequency resources, link resources, bearer resources, and related protocol processing resources occupied by the communication mode that was not determined as the primary bearer communication mode in steps S103 and S104. Since this communication mode no longer undertakes the main business data transmission task after the data migration is completed, continuing to maintain its complete operating state would cause unnecessary resource occupation and increased power consumption; therefore, it needs to be downgraded or released.

[0095] "Degradation processing" refers to adjusting the communication mode from a parallel bearer state to a low-power, low-activity, or standby state without completely releasing communication resources. For example, some radio frequency (RF) functional modules can be shut down, scheduling resource allocation reduced, or only the necessary network connection state can be retained so that it can be quickly restored when switching back later is required. This approach is suitable for scenarios that require a certain degree of switching flexibility. Conversely, "release processing" refers to completely releasing the communication resources occupied by the communication mode, including disconnecting the network connection, shutting down RF modules, and releasing the bearer and context information related to the communication mode in the protocol stack, so that the communication terminal no longer consumes additional resources for the communication mode. The choice between degradation processing and release processing can be made based on terminal strategy, service type, or network environment; this invention does not limit this choice.

[0096] In a specific implementation example, after confirming that the primary bearer communication mode is running stably, the communication terminal can first stop sending any new service data through the non-primary bearer communication mode and wait for its internal transmission buffer to be cleared. Then, it gradually releases the data bearer channel corresponding to this communication mode and switches its radio frequency module to a low-power state or a shutdown state. Finally, it clears the temporary session mapping relationships and scheduling control information related to this communication mode, thereby completing the resource reclamation process. Throughout the entire process, the communication terminal does not need to perform any reconstruction or renegotiation operations on the upper-layer services; the upper-layer services remain continuously running in the primary bearer communication mode.

[0097] Through the aforementioned degradation or release processes, the communication terminal completes the state transition from "dual-mode parallel bearer" to "stable operation in a single primary bearer communication mode," thus marking the end of a dual-mode communication handover process at the system level. This process achieves orderly convergence of communication resources without introducing communication interruptions or disrupting session continuity, enabling the communication terminal to have better resource utilization efficiency and power consumption performance after the handover.

[0098] In the above embodiments, a dual-mode communication method is provided. Correspondingly, this application also provides a dual-mode communication method system. Please refer to Figure 2, which is a schematic diagram of an embodiment of a dual-mode communication method system of this application. Since this embodiment, namely the second embodiment, is basically similar to the method embodiment, it is described simply. For relevant details, please refer to the description of the method embodiment. The system embodiment described below is merely illustrative.

[0099] The second embodiment of this application provides a dual-mode communication method system, comprising: an acquisition unit 201, configured to continuously acquire stability information, including signal quality, transmission errors, and service delay changes, during service transmission in a communication terminal using a first communication mode, and to form a forward-looking risk assessment basis for characterizing link degradation trends based on the stability information; an initiation unit 202, configured to initiate the radio frequency and access process of a second communication mode without terminating the service transmission in the first communication mode when the forward-looking risk assessment basis meets preset conditions, thereby enabling the second communication mode to enter a usable state capable of carrying service data in parallel; and a generation unit 203, configured to simultaneously process the first and second communication modes. When available, the system combines the link degradation trend with the channel conditions and network load of the two communication modes to generate a selection result for the primary bearer communication mode and a corresponding data migration strategy. The transfer unit 204 is used to gradually transfer service data to the primary bearer communication mode for carrying based on the selection result and data migration strategy, and to maintain the consistency of session identifier, transmission sequence and retransmission control status during the transfer process to achieve continuous service transmission. The switching unit 205 is used to perform degradation or release processing on communication resources that are not used as the primary bearer communication mode after confirming that the primary bearer communication mode has stably carried all service data, thereby completing the seamless switching of dual-mode communication.

[0100] Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

Claims

1. A dual-mode communication method, characterized in that, include: During the process of service transmission using the first communication mode in the communication terminal, stability information including signal quality, transmission errors and service latency changes is continuously acquired, and a forward-looking risk judgment basis for characterizing the link degradation trend is formed based on the stability information. When the forward-looking risk assessment criteria meet the preset conditions, without terminating the service transmission of the first communication mode, the radio frequency and access process of the second communication mode is initiated, so that the second communication mode can enter a usable state that can carry service data in parallel. When both the first and second communication modes are available, the link degradation trend and the channel conditions and network load conditions corresponding to the two communication modes are combined to generate the selection result of the main bearer communication mode and the corresponding data migration strategy. Based on the selection result of the primary bearer communication mode and the data migration strategy, the service data is gradually transferred to the primary bearer communication mode for carrying. During the transfer process, the consistency of session identifier, transmission sequence and retransmission control status is maintained to achieve continuous service transmission. After confirming that the primary bearer communication mode has stably carried all service data, the communication resources that are not used as the primary bearer communication mode are downgraded or released, thereby completing the seamless switching of dual-mode communication.

2. The dual-mode communication method according to claim 1, characterized in that, The method for forming a forward-looking risk assessment criterion based on stability information to characterize link degradation trends includes: in a communication terminal, synchronously sampling changes in signal quality, transmission errors, and service delays according to a preset sampling rhythm, and performing time alignment processing on different types of stability information based on sampling timestamps to form a set of stability feature vectors describing the link operating state within the same observation period; based on the set of stability feature vectors, calculating the change direction identifier and change magnitude parameter for each type of stability information within multiple consecutive observation periods, and combining the change direction identifier and change magnitude parameter to form a stability trend description set, wherein the stability trend description set is used to characterize the trend characteristics of the link state evolving from stable to unstable; performing consistency constraint judgment on the stability trend description set to determine whether the change direction identifiers of at least two types of stability information meet preset collaborative degradation conditions within the same time window, and generating a trend validity marker when the collaborative degradation conditions are met, which is used to indicate the continuous validity of the current link degradation trend in the time dimension; under the constraint of the trend validity marker, quantitatively evaluating the potential impact of link degradation based on the change magnitude parameter, generating a risk intensity parameter associated with the trend validity marker, and using the risk intensity parameter and the trend validity marker together as the forward-looking risk assessment criterion.

3. The dual-mode communication method according to claim 2, characterized in that, The process of performing consistency constraint determination on the stability trend description set, determining whether the change direction identifiers of at least two types of stability information satisfy a preset collaborative degradation condition within the same time window, and generating a trend validity marker when the collaborative degradation condition is met, to indicate the continuous validity of the current link degradation trend in the time dimension, includes: in the communication terminal, based on the stability trend description set, extracting the change direction identifier sequence of multiple types of stability information within the same time window according to a preset time window length, and organizing the change direction identifier sequence into a direction combination state set to describe the consistency of multiple indicator changes within the time window; based on the direction combination state set, determining whether there are at least two types of stability information change direction identifiers simultaneously in a predefined degradation direction set within the time window, and generating a window degradation consistency result when the determination is successful, to characterize the consistency state of multiple indicator degradation directions within the time window; performing correlation analysis on the window degradation consistency results corresponding to multiple consecutive time windows, determining whether the window degradation consistency results remain continuously valid in adjacent time windows, and generating a trend continuity determination result when the continuity condition is met, to characterize the persistence of link degradation in the time dimension; and generating a trend validity marker corresponding to the trend continuity determination result when the trend continuity determination result is successful.

4. The dual-mode communication method according to claim 1, characterized in that, When both the first and second communication modes are simultaneously available, the system combines the link degradation trend with the channel conditions and network load corresponding to the two communication modes to generate a result indicating the selection of the primary bearer communication mode and a corresponding data migration strategy. This includes: in the communication terminal, based on the judgment result representing the link degradation trend in the forward-looking risk judgment criteria, extracting the link risk reference parameters corresponding to the first and second communication modes at the current moment, and associating the link risk reference parameters with their respective communication mode identifiers to form a mode risk mapping set describing the degradation sensitivity of different communication modes; based on the mode risk mapping set, obtaining the real-time channel condition parameters and network load parameters corresponding to the first and second communication modes, and within the same evaluation period, combining the channel condition parameters and network load parameters... Load parameters and corresponding link risk reference parameters are combined to generate a mode bearer assessment state set reflecting the comprehensive bearer adaptability of each communication mode within the current assessment period. The main bearer determination rule is applied to the mode bearer assessment state set to compare the comprehensive bearer adaptability of different communication modes. When the preset main bearer switching conditions are met, the target main bearer communication mode is determined, and a bearer reconfiguration indication result corresponding to the target main bearer communication mode is generated to indicate the direction of the main bearer role change. Under the constraints of the bearer reconfiguration indication result, a data migration strategy matching the target main bearer communication mode is generated based on the bearer capability difference between the non-main bearer communication mode and the target main bearer communication mode. The data migration strategy includes at least data migration stage division information and data migration ratio information corresponding to each stage.

5. The dual-mode communication method according to claim 1, characterized in that, The process involves gradually transferring service data to the primary bearer communication mode based on the selection result of the primary bearer communication mode and the data migration strategy, while maintaining the consistency of session identifiers, transmission sequences, and retransmission control states during the transfer process to achieve continuous service transmission. This includes: in the communication terminal, determining the current migration stage of the service data based on the stage division information in the data migration strategy, and prioritizing the migration of the service data to be migrated according to the data migration ratio information corresponding to the migration stage, generating a service data migration queue corresponding to the current migration stage; based on the service data migration queue, extracting the session identifier, transmission sequence state, and retransmission control state corresponding to the service data to be migrated from the non-primary bearer communication mode, and organizing the session identifier, transmission sequence state, and retransmission control state into a session synchronization state. A session synchronization state set is used to describe the transmission context of the service data to be migrated in the non-primary bearer communication mode. Under the constraints of the session synchronization state set, the service data in the service data migration queue is sent through the target primary bearer communication mode according to the data migration ratio. During the transmission process, the session context in the primary bearer communication mode is dynamically aligned and updated based on the session synchronization state set to ensure that the session identifier, transmission sequence status, and retransmission control status in the primary bearer communication mode are consistent with those in the non-primary bearer communication mode. After confirming that the service data in the corresponding migration stage in the service data migration queue has been effectively carried in the primary bearer communication mode, the migration stage status flag is updated, and the service data migration operation of the next migration stage is triggered based on the updated migration stage status flag, until the migration of all service data to the primary bearer communication mode is completed.

6. The dual-mode communication method according to claim 1, characterized in that, When the forward-looking risk assessment criteria meet preset conditions, and without terminating the service transmission of the first communication mode, the radio frequency and access process of the second communication mode is initiated, enabling the second communication mode to enter a usable state capable of carrying service data in parallel. This includes: in the communication terminal, based on the trend validity marker and risk intensity parameter in the forward-looking risk assessment criteria, determining whether the second communication mode has the qualification to trigger early intervention in service carrying, and generating pre-activation indication information for the second communication mode when the qualification is determined to be met, to identify the initiation conditions for the second communication mode to enter the pre-activation process; under the constraint of the pre-activation indication information, performing a limited power start-up operation on the radio frequency unit of the second communication mode, and completing the initialization of the basic radio frequency parameters of the second communication mode while keeping the radio frequency configuration of the first communication mode unchanged, generating a radio frequency pre-activation status marker to characterize the working ready state of the radio frequency unit of the second communication mode; based on the radio frequency pre-activation status marker, triggering the access preparation process of the second communication mode, and completing the access verification and resource negotiation between the second communication mode and the network side without establishing a service data carrying channel, generating access availability status information to characterize the second communication mode's data carrying conditions; after the access availability status information is generated, marking the second communication mode as a parallel usable communication mode.

7. A dual-mode communication method system, characterized in that, include: The acquisition unit is used to continuously acquire stability information, including signal quality, transmission errors and changes in service latency, during the process of service transmission in the communication terminal using the first communication mode, and to form a forward-looking risk judgment basis for characterizing the link degradation trend based on the stability information. The startup unit is used to start the radio frequency and access process of the second communication mode without terminating the service transmission of the first communication mode when the forward-looking risk assessment criteria meet the preset conditions, so that the second communication mode can enter a usable state that can carry service data in parallel. The generation unit is used to generate a selection result for the primary bearer communication mode and a corresponding data migration strategy when both the first and second communication modes are available, taking into account the link degradation trend and the channel conditions and network load conditions corresponding to the two communication modes. The transfer unit is used to gradually transfer service data to the primary bearer communication mode for carrying based on the selection result of the primary bearer communication mode and the data migration strategy, and to maintain the consistency of session identifier, transmission sequence and retransmission control status during the transfer process to achieve continuous service transmission. The switching unit is used to perform degradation or release processing on communication resources that are not used as the primary bearer communication mode after confirming that the primary bearer communication mode has stably carried all service data, thereby completing the seamless switching of dual-mode communication.

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