Mobile terminal and method for quickly recovering mobile terminal from limited residence state

Abstract

The invention discloses a method for quickly recovering a mobile terminal from a limited residence state. And after the mobile terminal enters the limited residence state, performing neighbor cell measurement on the frequency point configured by the system message of the limited residence cell immediately. And the mobile terminal tries to read the SIB1 for each measured neighbor cell, and judges whether each neighbor cell which successfully reads the SIB1 is a suitable cell or not. When the first timer is overtime, the mobile terminal compares the distance L between the current position D2 and the position D1 in the limited residence state with a preset threshold; and if L is greater than the preset threshold, the access layer of the mobile terminal executes a full-band network searching process. And when the second timer is overtime, the access layer of the mobile terminal executes a full-band network searching process. The network selection opportunity of the mobile terminal is determined according to the corresponding relation between the position of the mobile terminal and the coverage of the mobile communication network, and unnecessary network selection operation is avoided.

Description

Technical Field

[0001] The present application relates to a mobile communication technology, and in particular to a method for restoring a mobile terminal from a restricted resident state to a normal resident state. Background Art

[0002] According to 3GPP technical specification 38.304, cells in a mobile communication network can be divided into the following four types based on whether mobile terminals are allowed to camp on the cells and the different services provided by the cells.

[0003] The first type: a suitable cell (also called a suitable cell). A mobile terminal is allowed to reside in a suitable cell. When a mobile terminal resides in a suitable cell, it is in a normal residency state. After residing in a suitable cell, the mobile terminal can initiate services normally. A suitable cell must meet the following conditions: (1) It is not a barred cell; (2) It meets the cell selection S criteria; (3) The PLMN (Public Land Mobile Network) of the cell belongs to the PLMN (Registered Public Land Mobile Network) or RPLMN (Equivalent Public Land Mobile Network) selected by the non-access stratum (NAS); (4) The tracking area (TA) of the cell does not belong to the forbidden tracking areas for roaming.

[0004] The second type is an acceptable cell. A mobile terminal is allowed to reside in an acceptable cell. A mobile terminal residing in an acceptable cell is in a restricted residency state. A mobile terminal residing in an acceptable cell can only obtain limited services, such as making emergency calls, and cannot perform normal voice or data services. An acceptable cell must meet the following conditions: (1) It must not be a prohibited cell; and (2) It must meet the cell selection criteria (S).

[0005] The third type: prohibited cell. The mobile terminal is not allowed to reside in the prohibited cell. The mobile terminal can only receive system messages in the prohibited cell but cannot perform services.

[0006] The fourth type: reserved cells. Mobile terminals are not allowed to reside in these cells. Reserved cells are used by operators to perform certain specific operations.

[0007] After a mobile terminal camps on a cell, there are only two camping states: normal camping state and restricted camping state.

[0008] After the mobile terminal successfully resides in a cell (whether in normal or restricted residency state), the cell reselection process is performed based on the system message on the network side and the signal quality of the neighboring cells measured by the mobile terminal. For mobile terminals in restricted residency state, some neighboring cells may be missed, thereby missing suitable cells and affecting user experience. For example, a mobile terminal using the SIM (User Identity Module) card of a first mobile communication operator resides on the network of a second mobile communication operator and enters a restricted residency state. The SIM card is a broad concept, including UIM cards, RUIM cards, USIM cards, eSIM cards, iSIM cards, etc. The network side sends neighboring cell measurement configuration information to the mobile terminal through a cell system message. The neighboring cell list contained in the neighboring cell configuration information is limited to the neighboring cells within the network of the second mobile communication operator, and the mobile terminal does not have the neighboring cell information of the network of the first mobile communication operator. According to 3GPP technical specifications 38.304 and 38.331, the mobile terminal will only perform neighboring cell measurement operations based on the neighboring cell configuration information contained in the received cell system message. In this case, the mobile terminal cannot detect the cell signal of the surrounding first mobile communication operator's network in time due to the limited measurement range, resulting in the mobile terminal being unable to resume normal stay in the first mobile communication operator's network in time, affecting services.

[0009] When a mobile terminal is in a restricted resident state, the conventional strategy is to trigger a recovery mechanism by starting a timer. When the timer expires, the mobile terminal re-initiates the network selection process in an attempt to return to a normal resident state. However, for a mobile terminal in a stationary state, the surrounding network environment typically does not change significantly. Therefore, frequently executing the network selection process will not restore the mobile terminal to a normal resident state. Instead, it will increase power consumption unnecessarily, seriously affecting the mobile terminal's battery life. Summary of the Invention

[0010] The technical problem to be solved by the present application is: how to shorten the time it takes for a mobile terminal to recover from a restricted resident state to a normal resident state, and reduce the power consumption of the mobile terminal during this process.

[0011] In order to solve the above technical problems, the present application proposes a method for a mobile terminal to quickly recover from a restricted residency state, comprising the following steps. Step S1: When the mobile terminal enters the restricted residency state, it immediately performs neighboring cell measurement on the frequency point configured by the system message of the restricted residency cell; at the same time, the mobile terminal records the current position D1, starts the first timer and the second timer, and sets the variable C of the number of cell selection attempts to 1; the timing length of the first timer is T1, and the timing length of the second timer is T2, and T1 < T2. Step S2: The mobile terminal attempts to read SIB1 for each measured neighboring cell, and determines whether each neighboring cell that successfully reads SIB1 is a suitable cell; if so, the mobile terminal resides in the suitable cell; after the mobile terminal enters the normal residency state, it turns off the first timer and the second timer, and sets the variable C of the number of cell selection attempts to 0, ending the entire process; if not, the mobile terminal decides whether to change the PLMN. Step S3: During or after the execution of step S2, when the first timer times out, the mobile terminal compares the distance L between the current location D2 and the location D1 when entering the restricted stay state with a preset threshold; if L> the preset threshold, the access layer of the mobile terminal performs a full-band network search process and returns to step S2; if no cell that can be normally resided is found after the full-band network search, the mobile terminal restarts the first timer and returns to step S3. During or after the execution of step S2, when the second timer times out, the access layer of the mobile terminal performs a full-band network search process and returns to step S2; if no cell that can be normally resided is found after the full-band network search, the mobile terminal increases the value of the variable C of the number of cell selection attempts by 1, sets the timing duration of the second timer to C×T2, and restarts the second timer.

[0012] Furthermore, in step S1, the frequencies configured in the system message of the restricted camped cell include all same-frequency, different-frequency, and different-standard frequencies.

[0013] Furthermore, in step S2, the mobile terminal camping in the suitable cell specifically includes: the access layer of the mobile terminal notifies the non-access layer, and the non-access layer triggers the initial registration process; after the mobile terminal successfully registers in the neighboring cell, it enters the normal camping state.

[0014] Furthermore, in step S2, the mobile terminal decides whether to change the PLMN specifically includes: the access layer of the mobile terminal reports the frequency, physical cell identifier, PLMN and tracking area identifier of the neighboring cell to the non-access layer, and the non-access layer of the mobile terminal decides whether to change the PLMN.

[0015] Furthermore, in step S2, in one case, the non-access layer of the mobile terminal decides not to change the PLMN, then the access layer of the mobile terminal performs a determination of another neighboring cell of the existing PLMN, and returns to step S2.

[0016] Furthermore, in step S2, in another case, the non-access layer of the mobile terminal decides to select a new PLMN, then the mobile terminal restarts the first timer and the second timer, and the access layer of the mobile terminal performs the judgment of the neighboring area of ​​the cell selection process of the new PLMN, and returns to step S2.

[0017] Furthermore, in step S3, if L≤preset threshold, no operation is performed.

[0018] Furthermore, in step S3, if the full-band network search caused by the first timer timeout is being executed when the second timer times out, the second timer timeout event is ignored and the full-band network search caused by the first timer timeout is continued.

[0019] Furthermore, in step S3, if the full-band network search caused by the second timer timeout is being executed when the first timer times out, the first timer timeout event is ignored and the full-band network search caused by the second timer timeout is continued.

[0020] The present application also proposes a mobile terminal that can quickly recover from a restricted residency state, including a measurement recording unit, a reading judgment unit, and a timeout judgment unit. The measurement recording unit is used to perform neighboring cell measurements on the frequency configured by the system message of the restricted residency cell immediately after the mobile terminal enters the restricted residency state; at the same time, the current position D1 of the mobile terminal is recorded, the first timer and the second timer are started, and the variable C of the number of cell selection attempts is set to 1; the timing length of the first timer is T1, and the timing length of the second timer is T2, and T1 < T2. The reading judgment unit is used to attempt to read SIB1 for each measured neighboring cell, and to determine whether each neighboring cell that successfully reads SIB1 is a suitable cell; if so, the mobile terminal resides in the suitable cell; the first timer and the second timer are turned off, and the variable C of the number of cell selection attempts is set to 0; if not, the mobile terminal decides whether to change the PLMN. The timeout judgment unit is used to compare the distance L between the current position D2 of the mobile terminal and the position D1 when entering the restricted residence state with a preset threshold when the first timer times out; if L>the preset threshold, execute the full-band network search process; if no cell that can be normally resided is found after the full-band network search, restart the first timer; the timeout judgment unit is also used to execute the full-band network search process when the second timer times out; if no cell that can be normally resided is found after the full-band network search, add 1 to the value of the variable C of the number of cell selection attempts, set the timing duration of the second timer to C×T2, and restart the second timer.

[0021] The technical effect achieved by this application is: introducing the location information of the mobile terminal, determining the timing of the mobile terminal's network selection (network search) based on the correspondence between the mobile terminal's location and the mobile communication network coverage, and avoiding unnecessary network selection (network search) operations. For example, when the mobile terminal has been staying in a restricted resident location, there is no need to initiate an unnecessary network search process, thereby significantly shortening the time it takes for the mobile terminal to return to a normal resident state, and significantly reducing the power consumption of the mobile terminal, providing users with a more lasting and efficient user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flowchart of a method for quickly recovering a mobile terminal from a restricted resident state proposed in this application.

[0023] Figure 2 This is a schematic diagram of the structure of a mobile terminal that quickly recovers from a restricted resident state proposed in this application.

[0024] Description of the reference numerals in the figure: measurement and recording unit 1, reading and judging unit 2, timeout judging unit 3. DETAILED DESCRIPTION

[0025] See also Figure 1 The method for quickly recovering a mobile terminal from a restricted resident state proposed in this application includes the following steps.

[0026] Step S1: When the mobile terminal enters the restricted camp state, it immediately performs neighbor cell measurements on all intra-frequency, inter-frequency, and inter-RAT frequencies configured in the system message of the restricted camp cell. At the same time, the mobile terminal records the current location D1, starts the first timer and the second timer, and sets the cell selection attempt count variable C to 1. The timing length of the first timer is T1, which represents the position measurement period. The timing length of the second timer is T2, which represents the cell selection period. T1 < T2. Typically, T2 < 2 × T1.

[0027] According to the existing communication protocol, after a mobile terminal resides in a cell (whether in normal or restricted residency state), there are certain conditions for starting the neighboring cell measurement configured by the system message of the resided cell, such as frequency priority, signal quality of the resided cell, etc. When the conditions are not met, the mobile terminal will not start the neighboring cell measurement, and therefore may miss the neighboring cell where the normal residency state can be restored. The present application optimizes the existing communication protocol at this step, and changes it to immediately start the neighboring cell measurement configured by the system message of the restricted residency cell after the mobile terminal enters the restricted residency cell, without considering whether other conditions are met, in order to increase the chance of measuring the neighboring cell where normal residency can be achieved.

[0028] Step S2: The mobile terminal attempts to read SIB1 (System Information Block Type 1) for each measured neighboring cell, and the access stratum (AS) of the mobile terminal determines whether each neighboring cell that successfully reads SIB1 is a suitable cell.

[0029] If so, the mobile terminal resides in the suitable cell. Specifically, the mobile terminal's access stratum notifies the non-access stratum, which triggers the initial registration procedure. The registration process establishes a connection between the mobile terminal and the neighboring cell, completing identity authentication, security encryption, and context establishment, ensuring smooth access to the neighboring cell. After the mobile terminal successfully registers in the neighboring cell, it enters a normal resident state. The mobile terminal deactivates the first and second timers, sets the variable C for the number of cell selection attempts to 0, and concludes the entire process.

[0030] If not, the access layer of the mobile terminal reports the frequency, physical cell identity, PLMN and tracking area identity (TAI) of the neighboring cell to the non-access layer, and the non-access layer of the mobile terminal decides whether to change the PLMN. In one case, the non-access layer of the mobile terminal decides not to change the PLMN, then the access layer of the mobile terminal performs the judgment of another neighboring cell of the existing PLMN and returns to step S2. In another case, the non-access layer of the mobile terminal decides to select a new PLMN, then the mobile terminal restarts (starts from zero) the first timer and the second timer, and the access layer of the mobile terminal performs the judgment of the neighboring cell of the new PLMN cell selection process and returns to step S2.

[0031] Step S3: During or after the execution of step S2, when the first timer times out, the mobile terminal compares the distance L between the current position D2 and the position D1 when entering the restricted residence state with the preset threshold. If L> the preset threshold, the access layer of the mobile terminal executes the full-band network search process, judges each scanned cell, and returns to step S2. If no cell that can be normally resided is found after the full-band network search, the network search operation is terminated, and the mobile terminal restarts (starts from zero) the first timer, returns to step S3, and waits for the first timer or the second timer to time out. If L≤the preset threshold, no operation is performed.

[0032] During or after step S2, if the second timer times out, the mobile terminal's access layer performs a full-band network search, checks each scanned cell, and returns to step S2. If no cell is found after the full-band network search, the mobile terminal increments the cell selection attempt count variable C by 1, sets the second timer duration to C × T2, and restarts the second timer (from zero).

[0033] In step S3, if the full-band network search caused by the first timer timeout is being executed when the second timer times out, the second timer timeout event is ignored and the full-band network search caused by the first timer timeout is continued.

[0034] In step S3, if the full-band network search caused by the second timer timeout is being executed when the first timer times out, the first timer timeout event is ignored and the full-band network search caused by the second timer timeout is continued.

[0035] See also Figure 2 The mobile terminal for quickly recovering from a restricted resident state proposed in this application includes a measurement and recording unit 1, a reading and judging unit 2, and a timeout judging unit 3. Figure 2 The mobile terminal shown corresponds to Figure 1 The method shown.

[0036] The measurement and recording unit 1 is configured to, when the mobile terminal enters the restricted camping state, immediately perform neighboring cell measurement on the frequency configured in the system message of the restricted camping cell; simultaneously record the current location D1 of the mobile terminal, start a first timer and a second timer, and set a variable C of the number of cell selection attempts to 1. The first timer has a timing length of T1, and the second timer has a timing length of T2, where T1 < T2.

[0037] The reading judgment unit 2 is configured to attempt to read the SIB1 for each measured neighboring cell and determine whether each neighboring cell for which the SIB1 is successfully read is a suitable cell. If so, the mobile terminal resides in the suitable cell; the first and second timers are deactivated, and a variable C for the number of cell selection attempts is set to 0. If not, the mobile terminal determines whether to change PLMNs.

[0038] The timeout judgment unit 3 is used to compare the distance L between the current position D2 of the mobile terminal and the position D1 when entering the restricted residence state with the preset threshold when the first timer times out. If L>the preset threshold, the full-band network search process is executed; if no cell that can be normally resided is found after the full-band network search, the first timer is restarted (starting from zero). The timeout judgment unit 3 is also used to execute the full-band network search process when the second timer times out; if no cell that can be normally resided is found after the full-band network search, the cell selection attempt number variable C value is increased by 1, the timing duration of the second timer is set to C×T2, and the second timer is restarted (starting from zero).

[0039] Cell signal coverage is closely tied to the location of mobile terminals. In cellular mobile communications, each cell has a limited coverage area, and only terminals within the signal coverage area can access that cell and obtain the corresponding services.

[0040] When the mobile terminal is in a stationary state, the mobile communication network environment in which the mobile terminal is located is unlikely to change. This application limits the number of times a stationary mobile terminal initiates a full-band network search by not performing any operation when the newly added L ≤ preset threshold, and exponentially increases the timing duration of the second timer after the second timer times out and the full-band network search fails, thereby reducing useless operations of the mobile terminal and thereby reducing the power consumption of the mobile terminal.

[0041] When a mobile terminal is in a mobile state, the mobile communication network environment it is in also changes accordingly. This application increases the number of times a mobile terminal in a mobile state initiates a full-band network search by adding the following restrictions: when T1 is reached and L> the preset threshold, and when T1<T2. This helps the mobile terminal more quickly obtain potential suitable cells from the restricted resident state and quickly return to the normal resident state.

[0042] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for quickly recovering a mobile terminal from a restricted resident state, characterized in that: The method includes the following steps: Step S1: When the mobile terminal enters the restricted camp state, it immediately performs neighboring cell measurement on the frequency configured in the system message of the restricted camp cell; at the same time, the mobile terminal records the current location D1, starts the first timer and the second timer, and sets the cell selection attempt number variable C to 1; the timing length of the first timer is T1, the timing length of the second timer is T2, and T1<T2; Step S2: The mobile terminal attempts to read the SIB1 for each measured neighboring cell and determines whether each neighboring cell for which the SIB1 is successfully read is a suitable cell; if so, the mobile terminal resides in the suitable cell; after the mobile terminal enters the normal residency state, the first timer and the second timer are turned off, and the variable C of the number of cell selection attempts is set to 0, thereby terminating the entire process; if not, the mobile terminal determines whether to change the PLMN; Step S3: During or after step S2, when the first timer times out, the mobile terminal compares the distance L between the current location D2 and the location D1 when entering the restricted stay state with a preset threshold; If L > the preset threshold, the access layer of the mobile terminal performs a full-band network search process and returns to step S2; if no cell that can be normally camped on is found after the full-band network search, the mobile terminal restarts the first timer and returns to step S3; During or after executing step S2, when the second timer times out, the access layer of the mobile terminal executes the full-band network search process and returns to step S2; if no cell that can be normally resided is found after the full-band network search, the mobile terminal adds 1 to the value of the variable C of the number of cell selection attempts, and also sets the timing duration of the second timer to C×T2, and restarts the second timer.

2. The method for quickly recovering a mobile terminal from a restricted stay state according to claim 1, wherein: In step S1, the frequency points configured in the system message of the restricted camping cell include all the same-frequency, different-frequency and different-standard frequency points.

3. The method for quickly recovering a mobile terminal from a restricted stay state according to claim 1, wherein: In step S2, the mobile terminal camping on the suitable cell specifically includes: the access layer of the mobile terminal notifies the non-access layer, and the non-access layer triggers the initial registration process; after the mobile terminal successfully registers in the neighboring cell, it indicates that it enters a normal camping state.

4. The method for quickly recovering a mobile terminal from a restricted stay state according to claim 1, wherein: In step S2, the mobile terminal decides whether to change the PLMN specifically includes: the access layer of the mobile terminal reports the frequency, physical cell identifier, PLMN and tracking area identifier of the neighboring cell to the non-access layer, and the non-access layer of the mobile terminal decides whether to change the PLMN.

5. The method for quickly recovering a mobile terminal from a restricted stay state according to claim 4, wherein: In step S2, in one case, the non-access layer of the mobile terminal decides not to change the PLMN, then the access layer of the mobile terminal performs a determination of another neighboring cell of the existing PLMN, and returns to step S2.

6. The method for quickly recovering a mobile terminal from a restricted stay state according to claim 4, wherein: In step S2, in another case, the non-access layer of the mobile terminal decides to select a new PLMN, then the mobile terminal restarts the first timer and the second timer, and the access layer of the mobile terminal performs the neighboring cell judgment of the new PLMN cell selection process, and returns to step S2.

7. The method for quickly recovering a mobile terminal from a restricted stay state according to claim 1, wherein: In step S3, if L≤preset threshold, no operation is performed.

8. The method for quickly recovering a mobile terminal from a restricted stay state according to claim 1, wherein: In step S3, if the full-band network search caused by the first timer timeout is being executed when the second timer times out, the second timer timeout event is ignored and the full-band network search caused by the first timer timeout is continued.

9. The method for quickly recovering a mobile terminal from a restricted stay state according to claim 1, wherein: In step S3, if the full-band network search caused by the second timer timeout is being executed when the first timer times out, the first timer timeout event is ignored and the full-band network search caused by the second timer timeout is continued.

10. A mobile terminal capable of quickly recovering from a restricted resident state, characterized in that: It includes a measurement and recording unit, a reading and judging unit, and a timeout judging unit; The measurement and recording unit is configured to, when the mobile terminal enters the restricted camping state, immediately perform neighboring cell measurement on the frequency point configured in the system message of the restricted camping cell; simultaneously record the current location D1 of the mobile terminal, start a first timer and a second timer, and set a variable C of the number of cell selection attempts to 1; the timing length of the first timer is T1, the timing length of the second timer is T2, and T1<T2; The reading judgment unit is configured to attempt to read the SIB1 for each measured neighboring cell, and determine whether each neighboring cell for which the SIB1 is successfully read is a suitable cell; if so, the mobile terminal resides in the suitable cell; close the first timer and the second timer, and set the cell selection attempt count variable C to 0; if not, the mobile terminal determines whether to change the PLMN; The timeout judgment unit is configured to compare the distance L between the current position D2 of the mobile terminal and the position D1 when the mobile terminal entered the restricted stay state with a preset threshold when the first timer times out; If L>the preset threshold, the full-band network search process is executed; if no cell in which normal residence is found after the full-band network search, the first timer is restarted; the timeout judgment unit is also used to execute the full-band network search process when the second timer times out; if no cell in which normal residence is found after the full-band network search, the cell selection attempt number variable C value is increased by 1, and the timing duration of the second timer is set to C×T2, and the second timer is restarted.

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