Method for out-of-service recovery for user equipment with multiple subscriber identity modules

Abstract

The application provides a method for out-of-service recovery of a user equipment (UE) having a first subscriber identity module (SIM) and a second subscriber identity module. The second subscriber identity module is intended to perform out-of-service recovery. The method comprises the following steps: scheduling a search of stored frequencies, full bands and different radio access technologies (RATs) according to different scenarios and service types of the first subscriber identity module; and prioritizing the order of the search of the stored frequencies, full bands and radio access technologies according to different scenarios and service types of the first subscriber identity module.

Description

[0001] This application claims priority to U.S. Provisional Application No. 63 / 749,012, filed January 24, 2025, and U.S. Application No. 19 / 448,488, filed January 14, 2026, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to user equipment (UE), and more particularly to an out-of-service (OOS) recovery method for a UE having multiple subscriber identity modules (SIMs). Background Technology

[0003] A No-Service (OOS) procedure is a method used to search for a suitable cell to camp on when a UE is powered on or when it fails to establish a connection with the network (i.e., the public land mobile network (PLMN) is lost). "Multiple SIMs" refers to a feature that allows mobile devices (such as smartphones and tablets) to support the use of multiple different SIM cards simultaneously. Key performance indicators (KPIs) for an OOS procedure using multiple SIMs include power consumption, recovery search time, and the proportion of interference to other different SIMs.

[0004] In different scenarios, using inappropriate strategies for this process can significantly reduce KPIs. For example, when a single SIM intends to search all supported frequencies and bands to find a suitable cell, it may interfere with the operation of other SIMs and unnecessarily consume power when there is no signal. A SIM intending to perform an OOS procedure blindly searching will result in unnecessary power consumption and a longer recovery time. Summary of the Invention

[0005] One embodiment of the present invention provides a method for no-service (OOS) recovery for a user equipment (UE) having a first user identity module (SIM) and a second user identity module. The second user identity module intends to perform no-service recovery. The method includes the following steps: scheduling searches for stored frequencies, full-band frequencies, and different radio access technologies (RATs) based on different scenarios and the service type of the first user identity module; prioritizing the search order of stored frequencies, full-band frequencies, and RATs based on different scenarios and the service type of the first user identity module.

[0006] According to the above method, the steps of scheduling the search for storage frequency, full frequency band and different radio access technologies according to different scenarios and the service type of the first user identity module include the following steps: in response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is Radio Resource Control (RRC) idle state, the first user identity module is used to intermittently perform Public Land Mobile Network (PLMN) search.

[0007] According to the above method, the step of intermittently performing a public land mobile network search using a first user identity module includes the following steps: in response to the first user identity module intending to perform radio resource management (RRM) or receive paging information, the first user identity module enters an active state; in response to the first user identity module not needing to perform RRM or receive paging information and the second user identity module not being in a no-service state, the first user identity module enters an inactive state; in response to the second user identity module intending to perform no-service recovery and the first user identity module about to enter an inactive state, the first user identity module enters an auxiliary no-service search state to perform a public land mobile network search.

[0008] According to the above method, the steps of scheduling the search for stored frequencies, full bands, and different radio access technologies based on different scenarios and the service type of the first user identity module include the following steps: In response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is Radio Resource Control (RRC) connection state, the second user identity module performs a public land mobile network search on the stored frequencies and iteratively performs a full band power scan (PS) and public land mobile network search on all frequencies; or, the second user identity module intermittently performs Received Signal Strength Indication (RSSI) sniffing on all stored frequencies; or, the second user identity module stops no-service recovery to prevent interference with the first user identity module.

[0009] According to the above method, the steps of using the second user identity module to perform a public land mobile network search on the stored frequencies and iteratively performing a full-band power scan and public land mobile network search on all frequencies include the following steps: In response to the user equipment failing to establish a link with the network, the second user identity module enters an active no-service state from initialization, and resets the no-service cycle timer to a first value and the no-service duration timer to a second value; In response to the expiration of the no-service cycle timer, the second user identity module enters an active no-service state from a stopped no-service state, and resets the no-service cycle timer to a first value and the no-service duration timer to a second value; The state before the stopped no-service state is the active no-service state; In response to the expiration of the passive no-service timer or the received signal strength indicator sniffing indicating that some frequency indicators exceed the threshold, the second user identity module enters an active no-service state from a passive no-service state.

[0010] According to the above method, the step of using the second user identity module to intermittently perform received signal strength indication sniffing on all stored frequencies includes the following steps: in response to the inability to identify a camping cell, even if it is a Limited Service and Public Alarm System (PWS) service, after completing the public land mobile network search for the stored frequencies and the full-band power scan and public land mobile network search for all frequencies, the second user identity module is caused to enter a passive no-service state from an active no-service state; in response to the expiration of the no-service cycle timer, the second user identity module is caused to enter a passive no-service state from a stopped no-service state, and the second user identity module resets the no-service cycle timer to the first value and the no-service duration timer to the second value; the state before the stopped no-service state is the passive no-service state.

[0011] According to the above method, the step of using the second user identity module to stop no-service recovery to prevent interference with the first user identity module includes the following steps: in response to the completion of a sub-function in the active no-service state, the expiration of the no-service duration timer, and the enable duty cycle being true, the second user identity module is moved from the active no-service state to the stopped no-service state; in response to the completion of a sub-function in the passive no-service state, the expiration of the no-service duration timer, and the enable duty cycle being true, the second user identity module is moved from the passive no-service state to the stopped no-service state.

[0012] According to the above method, the steps of using the second user identity module to perform a public land mobile network search on the stored frequencies and iteratively performing a full-band power scan and public land mobile network search on all frequencies include the following steps: performing a first function to collect information from the first user identity module, checking the radio resource control and operator combination of the first user identity module and the second user identity module, and determining the duty cycle for no-service recovery; performing a second function to optimize no-service recovery in different scenarios and adaptively modifying relevant parameters in different scenarios; and performing a third function to perform a public land mobile network search.

[0013] The method further includes the following steps: in response to detecting a suitable cell and successfully registering, the second user identity module enters the registered state from the active no-service state; in response to losing network connection and failing to re-establish in a radio link failure (RLF), the second user identity module enters the active no-service state from the registered state.

[0014] According to the above method, the steps of scheduling the search for storage frequency, full frequency band and different wireless access technologies according to different scenarios and the service type of the first user identity module include the following steps: in response to the first user identity module and the second user identity module having the same or shared network operator, and the service type of the first user identity module being Radio Resource Control (RRC) idle state or Radio Resource Control connected state, sharing network information with the second user identity module to avoid radio frequency preemption by the second user identity module.

[0015] According to the above method, the steps of scheduling the search for storage frequency, full frequency band and different wireless access technologies according to different scenarios and the service type of the first user identity module include the following steps: in response to the first user identity module and the second user identity module having the same or shared network, and the service type of the first user identity module being in a no-service state, performing no-service recovery using the first user identity module to obtain the result, and sharing the result with the second user identity module.

[0016] According to the above method, the steps of scheduling the search for storage frequency, full frequency band and different wireless access technologies according to different scenarios and the service type of the first user identity module include the following steps: in response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is in a no-service state, a joint frequency band search is performed on the storage frequency of the first and second user identity modules with the highest priority; the joint frequency band search takes into account the first and second user identity modules.

[0017] According to the above method, the steps of scheduling the storage frequency, full band and different wireless access technologies according to different scenarios and the service type of the first user identity module include the following steps: in response to the fact that the operators of the first user identity module and the second user identity module are different, the service type of the first user identity module is the radio resource control connection state, and the first user identity module performs call service, and performs no-service recovery that can be dual-received only during the call service.

[0018] According to the above method, the steps of scheduling the search for storage frequencies, full frequency bands, and different wireless access technologies based on different scenarios and the service type of the first user identity module include the following steps: in response to the fact that the operators of the first user identity module and the second user identity module are different, the service type of the first user identity module is wireless resource control connection state, and the first user identity module is playing games or playing videos, the search time is reduced instead of stopping the search for low-priority wireless access technologies or the full frequency band search; the frequency list is reordered and the search control is adaptively adjusted.

[0019] According to the above method, the steps for prioritizing the order of storage frequencies, full-band frequencies, and radio access technologies for search based on different scenarios and the service type of the first user identity module include the following steps: a frequency that is last camped in the storage frequencies, or measured from the measurement interval, or a preferred frequency, or a roaming registered public land mobile network, or a roaming home public land mobile network, or a roaming equivalent home public land mobile network is defined as high priority; a frequency detected from weak cells or removed from the high priority in the storage frequencies is defined as medium priority; all other frequencies that do not belong to high priority or medium priority are defined as low priority.

[0020] An embodiment of the present invention also provides a user equipment. The user equipment includes a first user identity module, a second user identity module, and a processor. The second user identity module is intended to perform no-service recovery. The processor is electrically connected to the first and second user identity modules. The processor schedules the search for storage frequencies, full-band frequencies, and different wireless access technologies based on different scenarios and the service type of the first user identity module. The processor prioritizes the order of storage frequencies, full-band frequencies, and wireless access technologies for the search based on different scenarios and the service type of the first user identity module.

[0021] According to the aforementioned user equipment, in response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is Radio Resource Control Idle State, the processor uses the first user identity module to intermittently perform a search for public land mobile networks.

[0022] According to the aforementioned user equipment, in response to the first user identity module intending to perform radio resource management or receive paging information, the processor puts the first user identity module into an active state. In response to the first user identity module not needing to perform radio resource management or receive paging information and the second user identity module not being in a no-service state, the processor puts the first user identity module into an inactive state. In response to the second user identity module intending to perform no-service recovery and the first user identity module about to enter an inactive state, the processor puts the first user identity module into an auxiliary no-service search state to perform a public land mobile network search.

[0023] According to the aforementioned user equipment, in response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is Radio Resource Control (RRC) connection state, the processor performs the following operations: the processor uses the second user identity module to perform a public land mobile network (PRM) search on the stored frequencies and iteratively performs a full-band power scan and PRM search on all frequencies; or, the processor uses the second user identity module to intermittently perform received signal strength indication sniffing on all stored frequencies; or, the processor stops no-service recovery to prevent interference to the first user identity module through the second user identity module.

[0024] According to the aforementioned user equipment, in response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is Radio Resource Control (RRC) connection state, the processor performs the following operations: In response to the user equipment failing to establish a link with the network, the processor causes the second user identity module to enter an active no-service state from initialization, and causes the second user identity module to reset the no-service cycle timer to the first value and the no-service duration timer to the second value; In response to the expiration of the no-service cycle timer, the processor causes the second user identity module to enter an active no-service state from a stopped no-service state, and causes the second user identity module to reset the no-service cycle timer to the first value and the no-service duration timer to the second value; The previous state before the stopped no-service state is the active no-service state; In response to the expiration of the passive no-service timer or the received signal strength indicator sniffing indicator indicating that some frequency indicators exceed the threshold, the processor causes the second user identity module to enter an active no-service state from a passive no-service state.

[0025] According to the aforementioned user equipment, in response to the inability to identify a camping cell, even with limited service and public alarm system service, after completing a public land mobile network search for the stored frequencies and a full-band power scan and public land mobile network search for all frequencies, the processor causes the second user identity module to transition from an active no-service state to a passive no-service state. Upon the expiration of the no-service cycle timer, the processor causes the second user identity module to transition from a stopped no-service state to a passive no-service state, and resets the no-service cycle timer to the first value and the no-service duration timer to the second value. The previous state before the stopped no-service state was the passive no-service state.

[0026] According to the aforementioned user equipment, in response to the expiration of the no-service period timer, the processor causes the second user identity module to transition from an active no-service state to a stopped no-service state. In response to the completion of a sub-function in the passive no-service state, the expiration of the no-service duration timer, and the enabled duty cycle being true, the processor causes the second user identity module to transition from a passive no-service state to a stopped no-service state.

[0027] Based on the aforementioned user equipment, the processor performs a first function to collect information from the first user identity module, examine the radio resource control and operator combination of the first and second user identity modules, and determine the duty cycle for no-service recovery. The processor performs a second function to optimize no-service recovery in different scenarios and adaptively modify relevant parameters in different scenarios. The processor performs a third function to perform a public terrestrial mobile network search.

[0028] Based on the aforementioned user equipment, in response to detecting a suitable cell and successfully registering, the processor causes the second user identity module to transition from an active no-service state to a registered state. In response to losing network connectivity and failing to re-establish it due to a radio link failure, the processor causes the second user identity module to transition from the registered state to an active no-service state.

[0029] According to the aforementioned user equipment, in response to the first user identity module and the second user identity module having the same or shared network operator, and the service type of the first user identity module being either Radio Resource Control (RRC) idle or RRC connected, the processor shares network information with the second user identity module to avoid radio frequency preemption by the second user identity module.

[0030] According to the aforementioned user equipment, in response to the fact that the first user identity module and the second user identity module are on the same or shared network, and the service type of the first user identity module is no service, the processor uses the first user identity module to perform no service recovery to obtain the result, and shares the result with the second user identity module.

[0031] Based on the aforementioned user equipment, in response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is in a no-service state, the processor performs a joint frequency band search on the storage frequencies of the first and second user identity modules with high priority. The joint frequency band search takes into account both the first and second user identity modules.

[0032] According to the aforementioned user equipment, in response to the fact that the operators of the first user identity module and the second user identity module are different, the service type of the first user identity module is Radio Resource Control Connection State, and the first user identity module performs call service, while the processor only performs no-service recovery that can perform dual reception.

[0033] Based on the aforementioned user equipment, in response to the fact that the operators of the first user identity module and the second user identity module are different, the service type of the first user identity module is Radio Resource Control (RRC) connection state, and the first user identity module is playing games or playing videos, the processor reduces the time-based search instead of stopping the search for low-priority radio access technologies or the full-band search. The processor reorders the frequency list and adaptively adjusts the search control.

[0034] Based on the aforementioned user equipment, the processor defines a frequency as high priority if it is the last frequency camped in the stored frequencies, or measured from the measurement interval, or a preferred frequency, or a roaming registered public land mobile network, or a roaming home public land mobile network, or a roaming equivalent home public land mobile network. The processor defines a frequency in the stored frequencies that is detected from weak cells or removed from the high priority range as medium priority. The processor defines all other frequencies that do not belong to high or medium priority as low priority. Attached Figure Description

[0035] The invention can be more fully understood by reading the following detailed description and referring to the examples in the accompanying drawings.

[0036] Figure 1 This is a flowchart of a method for performing No Service (OOS) recovery using a user equipment (UE) having a first user identity module (SIM) and a second user identity module according to some embodiments of the present invention.

[0037] Figure 2 This is a flowchart of a method for a user device having a first user identity module and a second user identity module to perform no-service recovery according to some embodiments of the present invention.

[0038] Figure 3 This is a schematic diagram illustrating the state transition of a first user identity module in response to a first user identity module being in a Radio Resource Control (RRC) idle state and a second user identity module being in a no-service state, according to some embodiments of the present invention.

[0039] Figure 4 This is a schematic diagram illustrating the state transition of a second user identity module in response to a first user identity module being in an RRC connected state and a second user identity module being in a no-service state, according to some embodiments of the present invention.

[0040] Figure 5 This is a timing diagram showing the alternating execution and cessation of no-service recovery of the second user identity module according to some embodiments of the present invention.

[0041] Figure 6 This is a timing diagram of the state transition of a second user identity module in response to a first user identity module being in an RRC connected state and a second user identity module being in a no-service state, according to some embodiments of the present invention.

[0042] Figure 7 This is a schematic diagram of a user equipment 700 according to some embodiments of the present invention. Detailed Implementation

[0043] To make the above-described objects, features and advantages of some embodiments of the present invention more readily understood, detailed descriptions are provided below in conjunction with the accompanying drawings.

[0044] Throughout this specification and the following claims, certain terms are used to refer to specific components. As will be understood by those skilled in the art, electronic device manufacturers may use different names to refer to a component. This invention is not intended to distinguish between components with different names but the same function. It should be understood that the words "comprising," "having," and "including" are used in an open-ended manner and should therefore be interpreted as "including but not limited to...". Therefore, when the terms "comprising," "having," or "including" are used in this invention to indicate the presence of a specific technical feature, value, method step, operation, unit, or component, the possibility of adding more technical features, values, method steps, working processes, units, components, or any combination thereof is not excluded.

[0045] Directional terms used throughout the specification and the following claims, such as “upper,” “above,” “lower,” “below,” “front,” “rear,” “back,” “left,” “right,” etc., refer only to directions indicated by the drawings. Therefore, directional terms are used to interpret, and not to limit, the invention. Regarding the drawings, they illustrate general features of methods, structures, or materials used in specific embodiments. However, the drawings should not be construed as defining or limiting the scope or properties covered by these embodiments. For example, for clarity, the relative size, thickness, and location of each layer, region, or structure may be reduced or enlarged.

[0046] When a component, such as a layer or area, is referred to as "on another component," it can be directly on that other component, or there may be other components between them. On the other hand, when a component is referred to as "directly on another component (or a variation thereof)," there are no other components between them. Furthermore, when a component is referred to as "on another component," the component and the other component have an arrangement relationship in the top view / vertical direction; the component can be below or above the other component, and the arrangement relationship in the top view / vertical direction is determined by the orientation of the device.

[0047] It should be understood that when a component or layer is said to be "connected to" another component or layer, it can be directly connected to that other component or layer, or there may be intermediate components or layers. Conversely, when a component is said to be "directly connected to" another component or layer, there are no intermediate components or layers.

[0048] The electrical connection or coupling described in this invention can refer to a direct connection or an indirect connection. In the case of a direct connection, the endpoints of components on two circuits are directly connected or connected through a wire segment, while in the case of an indirect connection, there is a switch, diode, capacitor, inductor, resistor, other suitable component, or combination of the above components between the endpoints of components on two circuits, but the intermediate component is not limited to these.

[0049] The terms "first," "second," and "third" are used to describe components. They are not used to indicate priority or sequence, but only to distinguish components with the same name.

[0050] It should be noted that the technical features in the different embodiments described below can be substituted for, recombine or mixed with each other to form another embodiment without departing from the spirit of the invention.

[0051] Figure 1 This is a flowchart illustrating a method for performing No Service (OOS) recovery on a user equipment (UE) having a first User Identity Module (SIM) and a second User Identity Module (UE), according to some embodiments of the present invention. The second User Identity Module is intended to perform No Service recovery. Figure 1 As shown, the no-service recovery method of the present invention includes the following steps: scheduling the search for storage frequency, full frequency band, and different radio access technologies (RATs) according to different scenarios and the service type of the first user identity module (step S100). Prioritizing the search by ordering the storage frequency, full frequency band, and RATs according to different scenarios and the service type of the first user identity module (step S102). Detailed descriptions of steps S100 and S102 are as follows. Figure 2 disclosed.

[0052] Figure 2This is a flowchart of a method for performing no-service recovery on a user device having a first user identity module and a second user identity module, according to some embodiments of the present invention. The second user identity module (e.g., Figure 2 The service type for SIM2 is "No Service". For example... Figure 2 As shown, in step S200, the method of the present invention determines the first user identity module (e.g., Figure 2 The method determines whether the SIM 1) and the second user identity module share the same operator. If the operators of the first user identity module and the second user identity module are different, condition C1 is satisfied. Alternatively, if the operators of the first user identity module and the second user identity module are the same or the first user identity module and the second user identity module share a network, condition C2 is satisfied. When condition C1 is satisfied, in step S202, the method of the present invention determines whether the service type of the first user identity module is Radio Resource Control (RRC) idle state, RRC connected state, or no service state. If the service type of the first user identity module is RRC idle state or RRC connected state, condition C3 is satisfied. Alternatively, if the service type of the first user identity module is no service state, condition C10 is satisfied.

[0053] When condition C3 is met, in step S204, the method of the present invention determines whether the service type of the first user identity module is RRC idle or RRC connected. When condition C10 is met, in step S214, the method of the present invention performs multi-user identity module no-service recovery. For example, the method of the present invention performs a joint frequency band search with the highest priority on the storage frequencies of the first and second user identity modules. The joint frequency band search takes into account both the first and second user identity modules.

[0054] When the service type of the first user identity module is RRC idle, condition C4 is satisfied. When the service type of the first user identity module is RRC connected, condition C5 is satisfied. When condition C4 is satisfied, the method of the present invention utilizes "background search" (step S208). For example, in some embodiments, the present invention uses the first user identity module to intermittently perform Public Land Mobile Network (PLMN) searches. When condition C5 is satisfied, in step S206, the method of the present invention determines whether the first user identity module is performing call service. When the first user identity module performs call service, condition C6 is satisfied. When the first user identity module plays a game or plays a video, condition C7 is satisfied.

[0055] When condition C6 is met, in step S210, the method of the present invention performs no-service recovery capable of dual reception (DR) only during call service. When condition C7 is met, the method of the present invention performs no-service recovery of the multi-user identity module (step S212). For example, the method of the present invention reduces the time-based search instead of stopping the search for low-priority radio access technologies or the entire frequency band search, and reorders the frequency list and adaptively adjusts the search control.

[0056] When condition C2 is met, in step S216, the method of the present invention determines whether the service type of the first user identity module is a wireless RRC connected state or a no-service state. In response to the first user identity module's service type being an RRC connected state or an RRC idle state, condition C8 is met. In response to the first user identity module's service type being a no-service state, condition C9 is met. When condition C8 is met, in step S218, the method of the present invention shares network information with the second user identity module to avoid radio frequency preemption by the second user identity module. When condition C9 is met, in step S220, the method of the present invention performs no-service recovery for a single user identity module. For example, the method of the present invention uses the first user identity module to perform no-service recovery to obtain a result and shares this result with the second user identity module.

[0057] Figure 3 This is a schematic diagram illustrating the state transition of a first user identity module in response to a first user identity module being in a Radio Resource Control (RRC) idle state and a second user identity module being in a no-service state, according to some embodiments of the present invention. Figure 3 As shown, the first user identity module enters the active state 302 from initialization 300. Condition C31 is satisfied in response to the first user identity module initially being in the auxiliary no-service search state 304 and intending to perform radio resource management (RRM) or receive paging information. The method of the present invention causes the first user identity module to enter the active state 302 when condition C31 is satisfied. Condition C34 is satisfied in response to the first user identity module initially being in the inactive state 306 and intending to perform radio resource management or receive paging information. The method of the present invention causes the first user identity module to enter the active state 302 when condition C34 is satisfied.

[0058] When the first user identity module does not need to perform radio resource management or receive paging information and the second user identity module is not in a no-service state, condition C33 is satisfied. The method of the present invention causes the first user identity module to enter an inactive state 306 from an active state 302 when condition C33 is satisfied. When the second user identity module intends to perform no-service recovery and the first user identity module is about to enter an inactive state 306, condition C32 is satisfied. The method of the present invention causes the first user identity module to enter an auxiliary no-service search state 304 from an active state 302 to perform a public land mobile network search when condition C32 is satisfied.

[0059] Figure 4 This is a schematic diagram illustrating the state transition of a second user identity module in response to a first user identity module being in an RRC connected state and a second user identity module being in a no-service state, according to some embodiments of the present invention. In response to the first user identity module and the second user identity module having different operators and the first user identity module being in an RRC connected state, the method of the present invention uses the second user identity module to perform a Public Land Mobile Network (PLMN) search on the stored frequencies and iteratively performs a full-band power scan (PS) and PLMN search on all frequencies.

[0060] For example, the method of the present invention causes the second user identity module to enter an active no-service state 402 from initialization 400 when the user equipment fails to establish a link with the network, and causes the second user identity module to reset the no-service cycle timer to a first value (e.g., the value OOS_WORK_PRD) and the no-service duration timer to a second value (e.g., the value OOS_WORK_DURATION). The method of the present invention causes the second user identity module to enter an active no-service state 402 from a stopped no-service state 406 when the no-service cycle timer expires (i.e., condition C42 is met), and causes the second user identity module to reset the no-service cycle timer to the first value and the no-service duration timer to the second value. The state prior to the stopped no-service state 406 is the active no-service state 402. The method of the present invention causes the second user identity module to enter an active no-service state 402 from a passive no-service state 404 when the passive no-service timer expires or when the received signal strength indicator sniffing indicates that a frequency metric exceeds a threshold (i.e., condition C44 is met). In some embodiments, a frequency metric may include the results of a power scan (PS).

[0061] Alternatively, in response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is RRC connected state, the method of the present invention intermittently uses the second user identity module to perform Received Signal Strength Indication (RSSI) sniffing on all stored frequencies. For example, the method of the present invention causes the second user identity module to enter the passive no-service state 404 from the active no-service state 402 after completing the PLMN search of the stored frequencies and the full-band PS and PLMN search of all frequencies, even if no campable cell is identified for limited service and Public Alarm System (PWS) service (i.e., condition C43 is met). The method of the present invention causes the second user identity module to enter the passive no-service state 404 from the stopped no-service state 406 when the no-service cycle timer expires (i.e., condition C45 is met), and causes the second user identity module to reset the no-service cycle timer to the first value and the no-service duration timer to the second value. The state before the stopped no-service state 406 is the passive no-service state 404.

[0062] Alternatively, in response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is RRC connection state, the method of the present invention stops using the second user identity module to restore the first user identity module from no-service status to prevent interference. For example, the method of the present invention causes the second user identity module to enter the stopped no-service status 406 from the active no-service status 402 when the sub-function of the second user identity module in the active no-service status 402 is completed, the no-service duration timer expires, and the enabled duty cycle is true (i.e., condition C41 is satisfied). The method of the present invention causes the second user identity module to enter the stopped no-service status 406 from the passive no-service status 404 when the sub-function of the second user identity module in the passive no-service status 404 is completed, the no-service duration timer expires, and the enabled duty cycle is true (i.e., condition C46 is satisfied).

[0063] exist Figure 4 In some embodiments, the method of the present invention causes the second user identity module to transition from an active no-service state 402 to a registration state 408 when a suitable cell is detected and registration is successful (i.e., condition C47 is satisfied). The method of the present invention causes the second user identity module to transition from a registration state 408 to an active no-service state 402 when a network connection is lost and re-establishment fails in a radio link failure (i.e., condition C48 is satisfied).

[0064] Figure 5 This is a timing diagram 500 showing the alternating execution and cessation of no-service recovery by the second user identity module according to some embodiments of the present invention. Figure 5As shown, the method of the present invention causes the second user identity module to perform no-service recovery 502 between time points t1 and t2, and between time points t3 and t4. The period between time points t1 and t2 is equal to the value of OOS_WORK_DURATION, which is set in the no-service duration timer when the second user identity module enters the active no-service state 402 from initialization 400 or stop no-service state 406, or when the second user identity module enters the passive no-service state 404 from stop no-service state 406. Furthermore, the method of the present invention causes the second user identity module to stop no-service recovery 504 between time points t2 and t3. The period between time points t1 and t3 is equal to the value of OOS_WORK_PRD, which is set in the no-service period timer when the second user identity module enters the active no-service state 402 from initialization 400 or stop no-service state 406, or when the second user identity module enters the passive no-service state 404 from stop no-service state 406.

[0065] Figure 6 This is a timing diagram of the state transitions of a second user identity module in response to a first user identity module being in a Radio Resource Control (RANC) connected state and a second user identity module being in a no-service state, according to some embodiments of the present invention. Figure 6 As shown, based on the time monitored in 604, the method of the present invention causes the second user identity module to alternate between an active no-service state 600 and a passive no-service state 602, and during the no-service recovery period, the period during which the second user identity module is in the passive no-service state 602 becomes increasingly longer. For example, the period during which the second user identity module is in the passive no-service state may increase from 20 seconds, 60 seconds, 90 seconds, 3 minutes to 6 minutes, but the present invention is not limited thereto.

[0066] Specifically, the method of the present invention causes the second user identity module to enter an active no-service state 600 between time points t01 and t10, and between time points t20 and t30. The method of the present invention causes the second user identity module to enter a passive no-service state 602 between time points t10 and t20. At time point t01, the passive no-service timer expires 604. Between time points t01 and t02, the method of the present invention causes the second user identity module to search across all stored frequencies. Between time points t02 and t03, the method of the present invention causes the second user identity module to search on operator-related frequencies. Between time points t03 and t04, the method of the present invention causes the second user identity module to search on mobile country code frequency bands based on location. Between time points t04 and t10, the method of the present invention causes the second user identity module to perform a full-band power scan and alternately perform a full-band public terrestrial mobile network search and a stored frequency search, finally searching for limited service or public alarm system service.

[0067] The method of this invention enables a second user identity module to intermittently perform received signal strength indication sniffing on all stored frequencies. For example, the second user identity module is enabled to perform received signal strength indication sniffing on all stored frequencies between time point t11 ​​and time point t12. At time point t20, the received signal strength indication sniffing indicates that the indicators of some frequencies exceed a threshold 608.

[0068] When the second user identity module is in an active no-service state 600, the method of the present invention executes a first function (e.g., the function LOAD_FROM_PEER_SIM) to collect information from the first user identity module, check the radio resource control and operator combination of the first and second user identity modules, and determine the duty cycle for no-service recovery. The method of the present invention executes a second function (e.g., the function LOAD_SCENARIO_PARAMETERS) to optimize no-service recovery in different scenarios and adaptively modify relevant parameters in different scenarios. The method of the present invention executes a third function (e.g., the function SEARCH_FOR_PLMN_AMONG_FREQ) to perform a public terrestrial mobile network search.

[0069] When the second user identity module is in the active no-service state 600 entry point, the functions LOAD_FROM_PEER_SIM, LOAD_SCENARIO_PARAMETERS, and SEARCH_FOR_PLMN_AMONG_FREQ are triggered. The SEARCH_FOR_PLMN_AMONG_FREQ function includes power scanning, cell search on all stored frequencies and across the entire frequency band, and cell measurement (if necessary).

[0070] In some embodiments, when the second user identity module is in the passive no-service state 602, the method of the present invention causes the second user identity module to reset the passive no-service timer to the value PASSIVE_OOS_PRD and the sleep timer to the value SLEEP_PRD. In some embodiments, the value PASSIVE_OOS_PRD is a function of the duration of the user equipment being in an asynchronous state. It increases over time. In some embodiments, when the sleep timer expires, the method of the present invention performs a power scan and cell search on new radios and a power scan on other radio access technologies on all stored frequencies. The corresponding code is shown below.

[0071] ```

[0072] if (2 SIMs are out-of-service)

[0073] PS / CS on all integrated stored frequencies for 2 SIMs;

[0074] else

[0075] PS / CS on all stored frequencies for one SIM;

[0076] if (the metric measured by PS (LTE) or CS (NR) on any frequency exceeds the threshold)

[0077] next_state = active-OOS state;

[0078] else

[0079] reset sleep_timer to SLEEP_PRD and enter sleep mode to save power.

[0080] ```

[0081] In some embodiments, when the passive no-service timer expires, the method of the present invention sets the next state to an active no-service state.

[0082] The code for the function LOAD_FROM_PEER_SIM is shown below.

[0083] ```

[0084] Reset OOS_WORK_DURATION, OOS_WORK_PRD to default value;

[0085] if (Dual SIM mode is ON) {

[0086] if (SIM1 operator == SIM2 operator || SIM1 and SIM2 share the same NW) {

[0087] if (any SIM is RRC_IDLE or RRC_CONNECTED) Notice {

[0088] Proceed to camp on the cell as non-OOS SIM does;

[0089] Exit OOS Recovery;

[0090] }

[0091] } else {

[0092] if (any SIM is RRC_IDLE) {

[0093] if (a frequency pass CM-PBCH criterion)

[0094] Try to camp on;

[0095] Exit OOS Recovery;

[0096] }

[0097] }

[0098] }.

[0099] ```

[0100] Note: This invention treats RRC_INACTIVE as RRC_IDLE. This invention only considers sharing between SIMs. This invention can improve the mechanism by taking network traffic into account.

[0101] The code for the function LOAD_SCENARIO_PARAMETERS is shown below.

[0102] ```

[0103] Reset OOS_WORK_DURATION, OOS_WORK_PRD to default value; Note 1

[0104] Reset DEC_STORED_PRD, DEC_FULL_PRD, PASSIVE_OOS_PRD and SLEEP_PRD to default value;

[0105] Set en_duty_cycle = 0;

[0106] Set en_2G_3G_search = 0;

[0107] Similar_flag = Link_Tracking( );

[0108] Adjustment_for_Duty_Cycle( scenario indicators, e.g., Weak Note 2 , Similar_flag);

[0109] Adjustment_for_On_Duration( scenario indicators);

[0110] if (Dual SIM mode is ON && any SIM is RRC_CONNECTED) {

[0111] Reduce_Low_Priority_RAT_Search( scenario indicators);

[0112] DEC_STORED_PRD and DEC_FULL_PRD = (DEC_STORED_PRD and DEC_FULL_PRD) x4;

[0113] SLEEP PRD = SLEEP PRD x 3;

[0114] PASSIVE_OOS_PRD = PASSIVE_OOS_PRD x 2;

[0115] }

[0116] ```

[0117] Note 1: These parameters are used to control the duty cycle during no-service recovery, such as... Figure 5 As shown. For example, the default OOS_WORK_DURATION is set to 400ms. The default OOS_WORK_PRD is set to 1000ms.

[0118] Note 2: This invention determines whether a user equipment has entered a weak field by tracking the received signal strength indication.

[0119] The code for the function SEARCH_FOR_PLMN_AMONG_FREQ is shown below.

[0120] L1_Window_Reduction( );

[0121] If ( mod(search counter, DEC_STORED_PRD) == 0 || the metric measured by PS (LTE) or CS (NR) on any frequency exceeds the threshold in Passive-OOS state) {

[0122] Part A -------------------------------------------------

[0123] if (2 SIMs are out-of-service)

[0124] PLMN search( ) on all integrated stored frequencies for 2 SIM;

[0125] else

[0126] PLMN search( ) on all stored frequencies for one SIM;

[0127] Part A -------------------------------------------------

[0128] if (2 SIMs are out-of-service)

[0129] PLMN search() on all integrated operator-relative + stored frequencies for 2 SIM;

[0130] else

[0131] PLMN search() on all operator-relative for one SIM;

[0132] if (2 SIMs are out-of-service)

[0133] PLMN search() on all integrated MCC for 2 SIM;

[0134] } else {

[0135] Part B--------------------------------------------------

[0136] if (2 SIMs are out-of-service)

[0137] PLMN search() on all integrated high priority frequencies for 2 SIM;

[0138] else

[0139] PLMN search() on all high priority frequencies for one SIM;

[0140] Part B--------------------------------------------------

[0141] }

[0142] Re_Order_Stored_Frequency ( );

[0143] The code in Part A searches all memory frequencies. The code in Part B searches only for high-priority frequencies. The codes in Part A and Part B may correspond to... Figure 6 The period between time points t01 and t04.

[0144] In some embodiments, the method of the present invention defines a frequency as high priority if it is the last camped frequency in the stored frequencies, or measured from a measurement interval, or a preferred frequency, or a roaming registered public land mobile network, or a roaming home public land mobile network, or a roaming equivalent home public land mobile network. The present invention defines a frequency as medium priority if it is detected as weak cell or removed from the high priority range in the stored frequencies. The present invention defines all other frequencies that do not belong to high or medium priority as low priority.

[0145] The code for the function SEARCH_FOR_PLMN_AMONG_FREQ is further shown below.

[0146] ```

[0147] Clear sub-band group list;

[0148] If (stop full-band search == 0 && mod(search counter, DEC_FULL_PRD) = = 0 ) {

[0149] Do {

[0150] Part C--------------------------------------------------

[0151] if (sub-band group list is empty) {

[0152] Perform full-band Power Scan on all supported frequencies;

[0153] Sort the frequencies which exceeds threshold and divide them into sub-band group and add into the sub-band group list;

[0154] }

[0155] Part C--------------------------------------------------

[0156] Part D--------------------------------------------------

[0157] if (2 SIMs are out-of-service)

[0158] PLMN search() on all frequencies within the first sub-band group in the list for 2 SIM;

[0159] else

[0160] PLMN search() on all frequencies within the first sub-band group in the list for one SIM;

[0161] if (a cell which exceeds the pre-defined threshold and register successfully)

[0162] next-state=NW-Registered State;

[0163] else

[0164] Remove the first sub-band group from the list;

[0165] Part D--------------------------------------------------

[0166] Part E------------------------------------------------------------------

[0167] if (2 SIMs are out-of-service)

[0168] PLMN search( ) on all integrated stored frequencies for 2 SIM;

[0169] else

[0170] PLMN search() on all stored frequencies for one SIM;

[0171] Part E------------------------------------------------------------------

[0172] } While (sub-band group list is not empty)

[0173] }

[0174] search counter++;

[0175] ```

[0176] The code in Part C is used for a one-time power scan. Full-band power scan frequency coverage should consider all hardware capabilities. The code in Part D is used for joint band search. The code in Part E is used for searching all stored frequencies. The codes in Parts C, D, and E may correspond to... Figure 6 The period between time point t04 and time point t10.

[0177] Figure 7 This is a schematic diagram of a user equipment 700 according to some embodiments of the present invention. Figure 7 As shown, User Equipment 700 includes a processor 702, a User Identity Module 704, a User Identity Module 706, a transceiver 708, and an antenna 710. The processor 702 is electrically connected to User Identity Modules 704 and 706. The transceiver 708 is electrically connected between the processor 702 and the antenna 710. User Identity Module 706 is intended to perform no-service recovery. The transceiver 708 receives or transmits radio signals through the antenna 710. The processor 702 schedules searches for stored frequencies, full-band frequencies, and different radio access technologies based on different scenarios and the service type of User Identity Module 704. The processor 702 prioritizes the order of stored frequencies, full-band frequencies, and radio access technologies for searches based on different scenarios and the service type of User Identity Module 704.

[0178] In some embodiments, in response to the fact that the operators of user identity module 704 and user identity module 706 are different and the service type of user identity module 704 is Radio Resource Control (RRC) idle state, processor 702 uses user identity module 704 to intermittently perform public land mobile network (PLC) searches. Specifically, processor 702 puts user identity module 704 into an active state when user identity module 704 intends to perform RRC or receive paging information. Processor 702 puts user identity module 704 into an inactive state when user identity module 704 does not need to perform RRC or receive paging information and user identity module 706 is not in a no-service state. Processor 702 puts user identity module 704 into an auxiliary no-service search state to perform PLC searches when user identity module 706 intends to perform no-service recovery and user identity module 704 is about to enter an inactive state.

[0179] In some embodiments, in response to the fact that the operators of User Identity Module 704 and User Identity Module 706 are different and the service type of User Identity Module 704 is Radio Resource Control (RANC) connected state, the processor 702 uses User Identity Module 706 to perform a Public Land Mobile Network (PLN) search on the stored frequencies and iteratively performs a full-band power scan and PLAN search on all frequencies. Alternatively, the processor 702 uses User Identity Module 706 to intermittently perform Received Signal Strength Indication (RSI) sniffing on all stored frequencies. Alternatively, the processor 702 stops using User Identity Module 706 for no-service recovery of User Identity Module 704 to prevent interference.

[0180] In some embodiments, processor 702 causes SIM 706 to enter an active no-service state from initialization when the user equipment fails to establish a connection with the network, and causes SIM 706 to reset the no-service cycle timer to a first value and the no-service duration timer to a second value. Processor 702 causes SIM 706 to enter an active no-service state from a stopped no-service state when the no-service cycle timer expires, and causes SIM 706 to reset the no-service cycle timer to a first value and the no-service duration timer to a second value. The previous state before the stopped no-service state is the active no-service state. Processor 702 causes SIM 706 to enter an active no-service state from a passive no-service state when the passive no-service timer expires or when a received signal strength indicator sniffing indicator for a frequency exceeds a threshold.

[0181] In some embodiments, processor 702 causes SIM 706 to transition from an active no-service state to a passive no-service state after completing a public land mobile network search on the stored frequencies and a full-band power scan and public land mobile network search on all frequencies, even if no campable cell is identified for limited service and public alarm system service. Processor 702 causes SIM 706 to transition from a stopped no-service state to a passive no-service state when the no-service cycle timer expires, and causes SIM 706 to reset the no-service cycle timer to a first value and the no-service duration timer to a second value. The preceding state before the stopped no-service state is the passive no-service state.

[0182] In some embodiments, processor 702 causes SIM 706 to transition from an active no-service state to a stopped no-service state when a sub-function in an active no-service state is completed, the no-service duration timer expires, and the enabled duty cycle is true. Processor 702 also causes SIM 706 to transition from a passive no-service state to a stopped no-service state when a sub-function in a passive no-service state is completed, the no-service duration timer expires, and the enabled duty cycle is true.

[0183] In some embodiments, processor 702 performs a first function to collect information from SIM 704, examine the radio resource control and operator combination of SIM 704 and SIM 706, and determine the duty cycle for no-service recovery. Processor 702 performs a second function to optimize no-service recovery in different scenarios and adaptively modify relevant parameters in different scenarios. Processor 702 performs a third function to perform a public terrestrial mobile network search.

[0184] In some embodiments, when the processor 702 detects a suitable cell and successfully registers, it causes the SIM 706 to enter a registered state from an active no-service state. When the processor 702 loses network connectivity and fails to re-establish the connection due to a radio link failure, it causes the SIM 706 to enter an active no-service state from the registered state.

[0185] In some embodiments, when SIM 702 shares network information with SIM 706 to avoid SIM 706 preempting radio frequency when SIM 704 and SIM 706 are on the same or shared network and SIM 704’s service type is in Radio Resource Control idle state or Radio Resource Control connected state.

[0186] In some embodiments, when SIM 704 and SIM 706 operate on the same or shared network, and the service type of SIM 704 is in a no-service state, the processor 702 performs no-service recovery using SIM 704 to obtain the result and shares the result with SIM 706.

[0187] In some embodiments, when SIM 704 and SIM 706 have different operators and SIM 704 is in a no-service state, the processor 702 performs a joint frequency band search on the stored frequencies of SIM 704 and SIM 706 with high priority. The joint frequency band search takes into account both SIM 704 and SIM 706.

[0188] In some embodiments, the processor 702 operates on different carriers for SIM 704 and SIM 706, and the service type of SIM 704 is in a radio resource control connection state. When SIM 704 is performing a call service, it only performs a no-service recovery that enables dual reception.

[0189] In some embodiments, in response to the fact that SIM 704 and SIM 706 have different operators, and SIM 704 is in a Radio Resource Control (RRC) connection state, and SIM 704 is playing a game or playing a video, processor 702 reduces the search time rather than stopping the search for low-priority radio access technologies or the full-band search, and reorders the frequency list and adaptively adjusts the search control.

[0190] In some embodiments, processor 702 defines a frequency as high priority if it is the last camped frequency in the stored frequencies, or measured from a measurement interval, or a preferred frequency, or a roaming registered public land mobile network, or a roaming home public land mobile network, or a roaming equivalent home public land mobile network. Processor 702 defines a frequency in the stored frequencies that is detected from weak cells or removed from the high priority range as medium priority. Processor 702 defines all other frequencies that do not belong to high or medium priority as low priority.

[0191] The goal of the no-service recovery method is to avoid interfering with non-no-service user identity modules. The no-service recovery method integrates single-user and dual-user identity modules. It adaptively reorders the priorities in the stored frequency list and adjusts the operating frequency according to different scenarios. When the two user identity modules belong to different operators and are both in a no-service state, the no-service recovery method performs a joint frequency band search.

[0192] While the invention has been described by way of examples and preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments. Rather, the invention is intended to cover various modifications and similar arrangements (as will be understood by those skilled in the art). Therefore, the scope of the claims should be given the broadest interpretation to cover all such modifications and similar arrangements.

Claims

1. A method for service-free recovery for a user equipment having a first user identity module and a second user identity module, wherein the second user identity module intends to perform the service-free recovery, characterized in that, The method includes: Based on different scenarios and the service type of the first user identity module, the system schedules searches for storage frequencies, the entire frequency band, and different wireless access technologies. Based on the different scenarios and the service type of the first user identity module, the search prioritizes the order of the storage frequency, the full frequency band, and the wireless access technology.

2. The method as described in claim 1, characterized in that, Based on different scenarios and the service type of the first user identity module, the steps for scheduling searches for the storage frequency, the full frequency band, and the different wireless access technologies include: In response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is Radio Resource Control Idle State, the first user identity module is used to intermittently perform a search for public land mobile networks.

3. The method as described in claim 2, characterized in that, The steps of intermittently performing the public land mobile network search using the first user identity module include: In response to the first user identity module's intention to perform radio resource management or receive paging information, the first user identity module is put into an active state; In response to the first user identity module not needing to perform radio resource management or receive the paging information and the second user identity module not being in a no-service state, the first user identity module is put into an inactive state; and In response to the second user identity module's intention to perform the no-service recovery and the first user identity module's imminent entry into the inactive state, the first user identity module enters an auxiliary no-service search state to perform the public land mobile network search.

4. The method as described in claim 1, characterized in that, The steps for scheduling searches for the storage frequency, the entire frequency band, and the different wireless access technologies, based on different scenarios and the service type of the first user identity module, include: responding to situations where the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is a radio resource control connection state. Using the second user identity module, perform a public land mobile network search on the stored frequency, and iteratively perform a full-band power scan and the public land mobile network search on all frequencies; or Using the second user identity module, intermittently perform received signal strength indication sniffing on all of the stored frequencies; or Use the second user identity module to stop the no-service recovery to prevent interference with the first user identity module.

5. The method as described in claim 4, characterized in that, The steps of using the second user identity module to perform the public land mobile network search on the stored frequency, and iteratively performing the full-band power scan and the public land mobile network search on all frequencies, include: In response to the user equipment's failure to establish a connection with the network, the second user identity module enters an active no-service state from initialization, and resets the no-service period timer to the first value and the no-service duration timer to the second value. In response to the expiration of the no-service period timer, the second user identity module transitions from the stopped no-service state to the active no-service state, and resets the no-service period timer to the first value and the no-service duration timer to the second value; wherein the state prior to the stopped no-service state is the active no-service state; and In response to the expiration of the passive no-service timer or the received signal strength indicator sniffing indicating that some frequency indicators exceed the threshold, the second user identity module is switched from the passive no-service state to the active no-service state.

6. The method as described in claim 5, characterized in that, The step of intermittently performing the received signal strength indication sniffing on all of the stored frequencies using the second user identity module includes: In response to the inability to identify a residing cell, even one with limited service and public alarm system service, after completing the public land mobile network search for the stored frequency and the full-band power scan and public land mobile network search for all frequencies, the second user identity module transitions from the active no-service state to the passive no-service state; and In response to the expiration of the no-service period timer, the second user identity module is caused to enter the passive no-service state from the stopped no-service state, and the second user identity module is caused to reset the no-service period timer to the first value and the no-service duration timer to the second value; wherein the state before the stopped no-service state is the passive no-service state.

7. The method as described in claim 6, characterized in that, The step of using the second user identity module to stop the no-service recovery to prevent interference with the first user identity module includes: in response to the completion of a sub-function in the active no-service state, the expiration of the no-service duration timer, and the enable duty cycle being true, causing the second user identity module to enter the stopped no-service state from the active no-service state; and in response to the completion of a sub-function in the passive no-service state, the expiration of the no-service duration timer, and the enable duty cycle being true, causing the second user identity module to enter the stopped no-service state from the passive no-service state.

8. The method as described in claim 4, characterized in that, The steps of using the second user identity module to perform the public land mobile network search on the stored frequency, and iteratively performing the full-band power scan and the public land mobile network search on all frequencies, include: performing a first function to collect information from the first user identity module, checking the radio resource control and operator combination of the first user identity module and the second user identity module, and determining the duty cycle for the no-service recovery; performing a second function to optimize the no-service recovery in the different scenarios and adaptively modifying relevant parameters in the different scenarios; and performing a third function to perform the public land mobile network search.

9. The method as described in claim 5, characterized in that, Further includes: In response to the detection of a suitable cell and successful registration, the second user identity module enters the registered state from the active no-service state. In response to the loss of network connection and failure to re-establish it in the event of a wireless link failure, the second user identity module is transferred from the registered state to the active no-service state.

10. The method as described in claim 1, characterized in that, The steps of scheduling the search for the storage frequency, the full frequency band, and the different wireless access technologies according to different scenarios and the service type of the first user identity module include: in response to the first user identity module and the second user identity module having the same or shared network operator, and the service type of the first user identity module being in a radio resource control idle state or a radio resource control connected state, sharing network information with the second user identity module to avoid radio frequency preemption by the second user identity module.

11. The method as described in claim 1, characterized in that, The steps of scheduling the search for the storage frequency, the full frequency band, and the different wireless access technologies according to different scenarios and the service type of the first user identity module include: in response to the first user identity module and the second user identity module having the same or shared network, and the service type of the first user identity module being in a no-service state, using the first user identity module to perform the no-service recovery to obtain the result, and sharing the result with the second user identity module.

12. The method as described in claim 1, characterized in that, The steps of scheduling the search for the storage frequency, the full frequency band, and the different wireless access technologies according to different scenarios and the service type of the first user identity module include: in response to the fact that the operators of the first user identity module and the second user identity module are different and the service type of the first user identity module is in a no-service state, performing a joint frequency band search on the storage frequency of the first and second user identity modules with the highest priority; wherein the joint frequency band search takes into account the first and second user identity modules.

13. The method as described in claim 1, characterized in that, The steps of scheduling the search for the storage frequency, the full frequency band, and the different wireless access technologies, based on different scenarios and the service type of the first user identity module, include: in response to the fact that the operators of the first user identity module and the second user identity module are different, the service type of the first user identity module is a radio resource control connection state, and the first user identity module is performing a call service, performing a no-service recovery that enables dual reception only during the call service.

14. The method as described in claim 1, characterized in that, The steps for scheduling the search for the storage frequency, the full frequency band, and the different wireless access technologies, based on different scenarios and the service type of the first user identity module, include: in response to the fact that the operators of the first user identity module and the second user identity module are different, the service type of the first user identity module is a wireless resource control connection state, and the first user identity module is playing games or playing videos, reducing the search time instead of stopping the search for low-priority wireless access technologies or the full frequency band search, and reordering the frequency list and adaptively adjusting the control of the search.

15. The method as described in claim 1, characterized in that, The steps for prioritizing the search based on the different scenarios and the service type of the first user identity module include: A frequency is defined as the frequency that is last camped in the storage frequency, or measured from the measurement interval, or the preferred frequency, or the roaming registered public land mobile network, or the roaming home public land mobile network, or the roaming equivalent home public land mobile network as high priority. A frequency detected from a weak cell or removed from a high-priority cell in the storage frequency is defined as a medium-priority frequency; and Define all frequencies that do not belong to high or medium priority as low priority.

16. A user equipment, characterized in that, include: A primary user identity module; A second user identity module intended to perform no-service recovery; as well as A processor is electrically connected to a first user identity module and a second user identity module, and is configured as follows: Based on different scenarios and the service type of the first user identity module, the system schedules searches for storage frequencies, the entire frequency band, and different wireless access technologies. Based on the different scenarios and the service type of the first user identity module, the search prioritizes the order of the storage frequency, the full frequency band, and the wireless access technology.

17. The user equipment as claimed in claim 16, characterized in that, In response to the fact that the first user identity module and the second user identity module are operated by different operators and the service type of the first user identity module is Radio Resource Control Idle State, the processor is configured to use the first user identity module to intermittently perform a search for public land mobile networks.

18. The user equipment as claimed in claim 17, characterized in that, The processor is configured as follows: In response to the first user identity module's intention to perform radio resource management or receive paging information, the first user identity module is put into an active state. In response to the first user identity module not needing to perform radio resource management or receive the paging information and the second user identity module not being in a no-service state, the first user identity module is put into an inactive state, and In response to the second user identity module's intention to perform the no-service recovery and the first user identity module's imminent entry into the inactive state, the first user identity module enters an auxiliary no-service search state to perform the public land mobile network search.

19. The user equipment as claimed in claim 16, characterized in that, In response to the fact that the first user identity module and the second user identity module operate on different carriers and that the service type of the first user identity module is Radio Resource Control (RRC) connection state, the processor is configured as follows: Using the second user identity module, perform a public land mobile network search on the stored frequencies, and iteratively perform a full-band power scan and the public land mobile network search on all frequencies; or Using the second user identity module, intermittently perform received signal strength indication sniffing on all stored frequencies; or Use the second user identity module to stop the no-service recovery to prevent interference with the first user identity module.

20. The user equipment as claimed in claim 19, characterized in that, The processor is configured as follows: In response to the user equipment's failure to establish a connection with the network, the second user identity module enters an active no-service state from initialization, and resets the no-service period timer to the first value and the no-service duration timer to the second value. In response to the expiration of the no-service period timer, the second user identity module transitions from the stopped no-service state to the active no-service state, and resets the no-service period timer to the first value and the no-service duration timer to the second value; wherein the state prior to the stopped no-service state is the active no-service state; and In response to the expiration of the passive no-service timer or the received signal strength indicator sniffing indicating that some frequency indicators exceed the threshold, the second user identity module is switched from the passive no-service state to the active no-service state.

21. The user equipment as claimed in claim 20, characterized in that, The processor is configured to: in response to the second user identity module being unable to identify a cell, even if it is a limited service and public alarm system service, after completing the public land mobile network search for the stored frequency and the full-band power scan and public land mobile network search for all frequencies; In response to the expiration of the no-service period timer, the second user identity module is caused to enter the passive no-service state from the stopped no-service state, and the second user identity module is caused to reset the no-service period timer to the first value and the no-service duration timer to the second value; wherein the state prior to the stopped no-service state is the passive no-service state.

22. The user equipment as claimed in claim 21, characterized in that, The processor is configured to: in response to the completion of a sub-function in the active no-service state and the expiration of the no-service duration timer and the enable duty cycle being true, cause the second user identity module to transition from the active no-service state to the stopped no-service state; Furthermore, in response to the completion of the sub-function in the passive no-service state, the no-service duration timer expires, and the duty cycle is enabled to be true, the second user identity module is caused to transition from the passive no-service state to the stopped no-service state.

23. The user equipment as claimed in claim 19, characterized in that, The processor is configured to: perform a first function to collect information from the first user identity module, check the radio resource control and operator combination of the first user identity module and the second user identity module, and determine the duty cycle of the no-service recovery; perform a second function to optimize the no-service recovery in the different scenarios and adaptively modify relevant parameters in the different scenarios; And to perform a third function to perform the search for the public land mobile network.

24. The user equipment as claimed in claim 20, characterized in that, The processor is configured to: in response to detecting a suitable cell and successfully registering, cause the second user identity module to enter the registered state from the active no-service state; In response to the loss of network connection and failure to re-establish it in the event of a wireless link failure, the second user identity module is transferred from the registered state to the active no-service state.

25. The user equipment as claimed in claim 16, characterized in that, The processor is configured to: in response to the first user identity module and the second user identity module having the same or shared network operator, and the service type of the first user identity module being Radio Resource Control (RRC) idle state or RRC connected state, share network information with the second user identity module to avoid radio frequency preemption by the second user identity module.

26. The user equipment as claimed in claim 16, characterized in that, The processor is configured to: in response to the first user identity module and the second user identity module being on the same or shared network, and the service type of the first user identity module being in a no-service state, perform the no-service recovery using the first user identity module to obtain a result, and share the result with the second user identity module.

27. The user equipment as claimed in claim 16, characterized in that, The processor is configured to: in response to the fact that the first user identity module and the second user identity module have different operators and the service type of the first user identity module is no service, perform a joint frequency band search with the highest priority on the storage frequency of the first and second user identity modules; wherein the joint frequency band search takes into account the first and second user identity modules.

28. The user equipment as claimed in claim 16, characterized in that, The processor is configured to: in response to the fact that the first user identity module and the second user identity module have different operators, the service type of the first user identity module is a radio resource control connection state, and the first user identity module performs a call service, perform a no-service recovery capable of dual reception only during the call service.

29. The user equipment as claimed in claim 16, characterized in that, The processor is configured to: in response to the fact that the first user identity module and the second user identity module have different operators, the service type of the first user identity module is a radio resource control connection state, and the first user identity module is playing games or playing videos, reduce the search time instead of stopping the search for low-priority radio access technology or the full-band search, and reorder the frequency list and adaptively adjust the control of the search.

30. The user equipment as claimed in claim 16, characterized in that, The processor is configured to: define a frequency as high priority if it is the last frequency camped in the stored frequencies, or measured from the measurement interval, or a preferred frequency, or a roaming registered public land mobile network, or a roaming home public land mobile network, or a roaming equivalent home public land mobile network; and define a frequency as medium priority if it is detected from a weak cell or removed from the high priority in the stored frequencies. And define all frequencies that do not belong to high priority and medium priority as low priority.

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