A cell handover method and device based on historical records

Abstract

This invention discloses a cell handover method based on historical records, comprising the following steps: Step S1: The mobile terminal saves the source cell information and target cell information of each failed cell handover command corresponding to a timeout of the T304 timer; this information is called the first historical record and is stored in the mobile terminal. Step S2: When the mobile terminal subsequently receives a cell handover command, it compares the cell handover command with the first historical record; if the source cell and target cell of the cell handover command are the same as those of the failed cell handover command corresponding to a timeout of the T304 timer in the first historical record, the mobile terminal reduces the timing duration of the T304 timer. This invention adjusts the timing duration of the T304 timer based on the historical record of previously failed cell handover commands, reducing the network outage duration when cell handover commands fail in the same scenario, thus improving the user experience.

Description

Technical Field

[0001] This invention relates to a method for a mobile terminal to switch cells. Background Technology

[0002] In cellular mobile communication, the cell handover for mobile terminals is assigned by the network side. In actual networks, handover failures often occur due to network planning, site conditions, and other factors.

[0003] The general process of a mobile terminal failing to hand over a cell is described as follows: (1) The mobile terminal is working in source cell A. It measures the signal strength of cell B and finds that it meets the requirements for a measurement report, and reports it to the network. (2) The network sends an RRC Connection Reconfiguration message containing the target cell B configuration and the duration of the T304 timer. RRC stands for Radio Resource Control. (3) The mobile terminal attempts to access cell B randomly according to the network configuration. (4) Due to the field environment, the status of cell B base station, the mobile terminal moving too fast, etc., the mobile terminal cannot access cell B successfully. (5) The mobile terminal keeps trying to access cell B until the T304 timer expires, and initiates the RRC re-establishment procedure in source cell A.

[0004] When a mobile terminal receives a cell handover command, it starts a T304 timer. If it successfully accesses the new cell, the T304 timer terminates. If the T304 timer times out, it indicates that access to the target cell has failed, and the mobile terminal performs corresponding resource rollback and initiates an RRC connection reconstruction process. Throughout this entire process, the mobile terminal's radio link remains abnormal. If the T304 timer duration is configured too long, the mobile terminal will remain in an abnormal state for an extended period. During this time, the mobile terminal is offline. Summary of the Invention

[0005] The technical problem to be solved by this invention is: how to reduce the network outage duration of mobile terminals when cell handover fails.

[0006] To address the aforementioned technical problems, this invention proposes a cell handover method based on historical records, comprising the following steps: Step S1: The mobile terminal saves the source cell information and target cell information of each failed cell handover command corresponding to a timeout of the T304 timer; this information is called the first historical record and is stored in the mobile terminal. Step S2: When the mobile terminal subsequently receives a cell handover command, it compares the cell handover command with the first historical record; if the source cell and target cell of the cell handover command are the same as those of the failed cell handover command corresponding to a timeout of the T304 timer in the first historical record, the mobile terminal reduces the timing duration of the T304 timer.

[0007] Preferably, if the mobile terminal receives an RRC connection reconfiguration message after receiving multiple cell handover commands for both the source cell and the target cell, then step S2 is stopped, and the cell handover is still performed using the timing duration of the T304 timer issued by the network side.

[0008] Optionally, step S1 is changed to step S1a, and step S2 is changed to step S2a. Step S1a: The mobile terminal saves the source cell information, target cell information, and the mobile terminal's current location information for each failed cell handover command corresponding to a timeout of the T304 timer; this information is called the second historical record and is stored in the mobile terminal. Step S2a: When the mobile terminal subsequently receives a cell handover command, it compares the cell handover command, the current mobile terminal location, and the second historical record; if the source cell, target cell, and the source cell and target cell of the failed cell handover command corresponding to a timeout of the T304 timer in the second historical record are all the same, and the current mobile terminal location is close to the mobile terminal location at the time corresponding to that timeout of the T304 timer in the second historical record, then the mobile terminal reduces the timing duration of the T304 timer.

[0009] Preferably, if the mobile terminal receives an RRC connection reconfiguration message after receiving multiple cell handover commands from the same source cell and target cell, and the mobile terminal is in a similar location, then step S2a is stopped, and the cell handover is still performed using the timing duration of the T304 timer issued by the network side.

[0010] For example, "proximity" means that the geographical coordinates are within 50 meters apart.

[0011] For example, in steps S1 and S1a, the first historical record and the second historical record are stored in the baseband database of the mobile terminal.

[0012] Preferably, in steps S2 and S2a, the mobile terminal reduces the timing duration of the T304 timer by selecting a value that is one or two levels lower than the current value configured by the network from among multiple fixed values ​​for the timing duration of the T304 timer.

[0013] Preferably, in steps S2 and S2a, the timing duration of the T304 timer is at least 100ms.

[0014] This invention also proposes a cell handover device based on historical records, including a first recording unit and a first comparison execution unit. The first recording unit stores the source cell information and target cell information of failed cell handover commands corresponding to each timeout of the T304 timer in the mobile terminal; this information is called the first historical record. The first comparison execution unit compares the cell handover command with the first historical record when the mobile terminal subsequently receives a cell handover command; if the source cell and target cell of the cell handover command are the same as the source cell and target cell of the failed cell handover command corresponding to a certain timeout of the T304 timer in the first historical record, the timing duration of the T304 timer is reduced.

[0015] Optionally, the first recording unit is replaced by a second recording unit, and the first comparison execution unit is replaced by a second comparison execution unit. The second recording unit is used to store the source cell information, target cell information, and the mobile terminal's current location information of the failed cell handover command corresponding to each time the T304 timer times out in the mobile terminal; this information is called the second historical record. The second comparison execution unit is used to compare the cell handover command, the current mobile terminal location, and the second historical record when the mobile terminal subsequently receives a cell handover command; if the source cell, target cell, current mobile terminal location, and the source cell, target cell, and current mobile terminal location of the failed cell handover command corresponding to a certain timeout of the T304 timer in the second historical record are all the same, then the timing duration of the T304 timer is reduced.

[0016] The technical effect achieved by this invention is that by adjusting the timing duration of the T304 timer based on the historical records of previously failed cell handover commands, the network outage duration when cell handover commands fail in the same scenario is reduced, thereby improving the user experience. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating an embodiment of the cell handover method based on historical records proposed in this invention.

[0018] Figure 2 This is a flowchart illustrating Embodiment 2 of the cell handover method based on historical records proposed in this invention.

[0019] Figure 3 This is a schematic diagram of an embodiment of the cell handover device based on historical records proposed in this invention.

[0020] Figure 4 This is a schematic diagram of the second embodiment of the cell handover device based on historical records proposed in this invention.

[0021] The following are the annotations in the figure: 1 is the first recording unit, 2 is the first comparison execution unit, 1a is the second recording unit, and 2a is the second comparison execution unit. Detailed Implementation

[0022] Please see Figure 1 The first embodiment of the cell handover method based on historical records proposed in this invention includes the following steps.

[0023] Step S1: Each timeout of the T304 timer indicates a failed cell handover command. The mobile terminal saves the source cell information and target cell information of the failed cell handover command corresponding to each time the T304 timer expires. This information is called the first historical record and is stored within the mobile terminal, for example, in the baseband (modem) database.

[0024] Step S2: When the mobile terminal subsequently receives a cell handover command, it compares the cell handover command with the first historical record. If the source cell and target cell of the cell handover command are the same as the source cell and target cell of the failed cell handover command corresponding to a timeout of the T304 timer in the first historical record, the mobile terminal reduces the timing duration of the T304 timer.

[0025] After step S2, the mobile terminal starts the T304 timer with a new timing duration to initiate the cell handover process. If the cell handover is successful, the T304 timer is terminated. If the T304 timer times out, it indicates that the cell handover has failed, and the mobile terminal performs corresponding resource rollback and initiates the RRC connection reconstruction process. The method described in this invention can be executed multiple times in a loop. If the mobile terminal receives an RRC connection reconfiguration message after receiving cell handover commands for both the source and target cells multiple times (more than three times), it indicates that the mobile terminal has failed to execute the same cell handover command multiple times consecutively in the nearby area. This indicates that the network side believes there is only one suitable neighboring cell. At this point, step S2 is stopped, the optimization mechanism is not triggered, and the cell handover is still performed using the timing duration of the T304 timer issued by the network side, thus giving the mobile terminal and the network a greater chance to complete random access.

[0026] Please see Figure 2 The second embodiment of the cell handover method based on historical records proposed in this invention includes the following steps.

[0027] Step S1a: Each timeout of the T304 timer indicates a failed cell handover command. The mobile terminal saves the source cell information, target cell information, and the mobile terminal's location information for each failed cell handover command corresponding to a timeout of the T304 timer. The mobile terminal's location information can be obtained through the positioning module (e.g., GPS, BeiDou) in the mobile terminal. This information, called the second historical record, is stored within the mobile terminal, for example, in the baseband database.

[0028] Step S2a: When the mobile terminal subsequently receives a cell handover command, it compares the cell handover command, the current mobile terminal location, and the second historical record. If the source cell and target cell of the cell handover command are the same, and the source cell and target cell of the failed cell handover command corresponding to a timeout of the T304 timer in the second historical record are both the same, and the current mobile terminal location is close to the mobile terminal location at the time corresponding to that timeout of the T304 timer in the second historical record, then the mobile terminal reduces the timing duration of the T304 timer. "Closely close" means, for example, that the geographical coordinates are within 50 meters.

[0029] After step S2a, the mobile terminal starts the T304 timer with a new timing duration to initiate the cell handover process. If the cell handover is successful, the T304 timer is terminated. If the T304 timer times out, it indicates that the cell handover has failed, and the mobile terminal performs corresponding resource rollback and initiates the RRC connection reconstruction process. The method described in this invention can be executed multiple times in a loop. If the mobile terminal receives an RRC connection reconfiguration message after receiving cell handover commands from the same source cell and target cell (which are both the same and the mobile terminal is in a similar location) multiple times (more than three times), it indicates that the mobile terminal has failed to execute the same cell handover command multiple times at the same location. This means that the network side believes there is only one suitable neighboring cell at this location. In this case, step S2a is stopped, the optimization mechanism is not triggered, and the T304 timer timing duration issued by the network side is still used for cell handover, thus giving the mobile terminal and the network a greater chance to complete random access.

[0030] The timing duration of the T304 timer can take multiple specified values, such as 50ms, 100ms, 150ms, 200ms, 500ms, 1000ms, 2000ms, and 10000ms. Preferably, in steps S2 and S2a, reducing the timing duration of the T304 timer on the mobile terminal means lowering the network configuration value by one or two levels. For example, if the network-side setting for the T304 timer's timing duration is 10000ms, lowering it by one level would be 2000ms, and lowering it by two levels would be 1000ms. The effectiveness of this invention in reducing network outage duration is particularly noticeable when the timing duration of the T304 timer is changed from 10 seconds to 2 seconds, or from 2 seconds to 1 second. Preferably, in steps S2 and S2a, the minimum timing duration of the T304 timer is 100ms, meaning it will not be changed to a lower value.

[0031] By using the method described in this invention, in locations where cell handover failures frequently occur, mobile terminals can return to their original serving cell more quickly, minimizing the abnormal time of the air interface, i.e. reducing network outage duration, and providing users with a better experience.

[0032] Please see Figure 3 The first embodiment of the cell handover device based on historical records proposed in this invention includes a first recording unit 1 and a first comparison execution unit 2. Figure 3 The device shown corresponds to Figure 1 The method shown.

[0033] The first recording unit 1 is used to store the source cell information and target cell information of the failed cell handover command corresponding to each time the T304 timer times out in the mobile terminal. This information is called the first historical record.

[0034] The first comparison execution unit 2 is used to compare the cell handover command with the first historical record when the mobile terminal subsequently receives a cell handover command. If the source cell and target cell of the cell handover command are the same as the source cell and target cell of the failed cell handover command corresponding to a timeout of the T304 timer in the first historical record, the timing duration of the T304 timer is reduced.

[0035] Please see Figure 4 The second embodiment of the cell handover device based on historical records proposed in this invention includes a second recording unit 1a and a second comparison execution unit 2a. Figure 4 The device shown corresponds to Figure 2 The method shown.

[0036] The second recording unit 1a is used to store the source cell information, target cell information, and the mobile terminal's location information for each failed cell handover command corresponding to a timeout of the T304 timer in the mobile terminal. This information is called the second historical record.

[0037] The second comparison execution unit 2a is used to compare the cell handover command, the current location of the mobile terminal, and the second historical record when the mobile terminal subsequently receives a cell handover command. If the source cell and target cell of the cell handover command are the same as those of the failed cell handover command corresponding to a timeout of the T304 timer in the second historical record, and the current location of the mobile terminal is close to the location of the mobile terminal at the time of that timeout of the T304 timer in the second historical record, then the timing duration of the T304 timer is reduced. "Closely close" means, for example, that the geographical coordinates are within 50 meters apart.

[0038] This invention adjusts the timing duration of the T304 timer based on historical records. If a handover from source cell A to target cell B has failed in the past, this application reduces the timing duration of the T304 timer. Embodiment 2 further adds a condition that the current mobile terminal location is close to the mobile terminal location in the failure history, thereby reducing the network outage time and improving the user experience when the current cell handover fails.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cell handover method based on historical records, characterized in that, Includes the following steps; Step S1: When the mobile terminal receives the cell handover command, it starts the T304 timer; if the T304 timer expires and the target cell is still not accessed, it means that the target cell access has failed. The mobile terminal stores the source cell information and target cell information of the failed cell handover command corresponding to each time the T304 timer expires; This information, known as the first historical record, is stored within the mobile device. Step S2: When the mobile terminal receives a cell handover command later, it compares the cell handover command with the first historical record; if the source cell and target cell of the cell handover command are the same as the source cell and target cell of the failed cell handover command corresponding to a certain timeout of the T304 timer in the first historical record, the mobile terminal reduces the timing duration of the T304 timer. Step S3: The mobile terminal starts the T304 timer with the new timing duration to perform the cell handover process; if the T304 timer times out, it means that the cell handover has failed, and the mobile terminal initiates the RRC connection reconstruction process in the source cell.

2. The cell handover method based on historical records according to claim 1, characterized in that, If the mobile terminal receives an RRC connection reconfiguration message after receiving multiple cell handover commands for both the source and target cells, it will stop executing step S2 and continue to use the timing duration of the T304 timer issued by the network side for cell handover.

3. The cell handover method based on historical records according to claim 1, characterized in that, Step S1 is changed to step S1a, and step S2 is changed to step S2a. Step S1a: When the mobile terminal receives the cell handover command, the T304 timer is started; if the T304 timer expires and the target cell is still not accessed, it means that the target cell access has failed. The mobile terminal saves the source cell information, target cell information, and the mobile terminal's location information for each failed cell handover command corresponding to the T304 timer timeout. This information, known as the second history record, is stored within the mobile device. Step S2a: When the mobile terminal subsequently receives a cell handover command, it compares the cell handover command, the current mobile terminal location, and the second historical record. If the source cell and target cell of the cell handover command and the source cell and target cell of the failed cell handover command corresponding to a certain timeout of the T304 timer in the second historical record are the same, and the current mobile terminal location is close to the mobile terminal location at the time corresponding to that timeout of the T304 timer in the second historical record, then the mobile terminal reduces the timing duration of the T304 timer. Step S3a: The mobile terminal starts the T304 timer with the new timing duration to perform the cell handover process; if the T304 timer times out, it means that the cell handover has failed, and the mobile terminal initiates the RRC connection reconstruction process in the source cell.

4. The cell handover method based on historical records according to claim 3, characterized in that, If the mobile terminal receives an RRC connection reconfiguration message after receiving multiple cell handover commands from the same source cell and target cell, and the mobile terminal is in a similar location, then step S2a is stopped, and the cell handover is still performed using the timing duration of the T304 timer issued by the network side.

5. The cell handover method based on historical records according to claim 3, characterized in that, The term "similar location" refers to geographical coordinates that are within 50 meters of each other.

6. The cell handover method based on historical records according to claim 1 or 3, characterized in that, In steps S1 and S1a, the first historical record and the second historical record are stored in the baseband database of the mobile terminal.

7. The cell handover method based on historical records according to claim 1 or 3, characterized in that, In steps S2 and S2a, the mobile terminal reduces the timing duration of the T304 timer by selecting a value that is one or two levels lower than the current value configured by the network from among multiple fixed values ​​for the timing duration of the T304 timer.

8. The cell handover method based on historical records according to claim 1 or 3, characterized in that, In steps S2 and S2a, the minimum timing duration of timer T304 is 100ms.

9. A cell handover device based on historical records, characterized in that, It includes a first recording unit and a first comparison execution unit; The first recording unit is used to store the source cell information and target cell information of the failed cell handover command corresponding to each time the T304 timer expires in the mobile terminal; this information is called the first historical record; when the mobile terminal receives a cell handover command, the T304 timer is started; if the T304 timer expires and the target cell is still not accessed, it means that the target cell access has failed. The first comparison execution unit is used to compare the cell handover command with the first historical record when the mobile terminal subsequently receives a cell handover command. If the source cell and target cell of the cell handover command are the same as the source cell and target cell of the failed cell handover command corresponding to a certain timeout of the T304 timer in the first historical record, the timing duration of the T304 timer is reduced. Subsequently, the mobile terminal uses the new timing duration to start the T304 timer and perform the cell handover process. If the T304 timer times out, it indicates that the cell handover has failed, and the mobile terminal initiates the RRC connection reconstruction process in the source cell.

10. The cell handover device based on historical records according to claim 9, characterized in that, The first recording unit is changed to the second recording unit, and the first comparison execution unit is changed to the second comparison execution unit; The second recording unit is used to store the source cell information, target cell information, and mobile terminal location information of the failed cell handover command corresponding to each time the T304 timer expires in the mobile terminal; this information is called the second historical record; when the mobile terminal receives a cell handover command, the T304 timer is started; if the T304 timer expires and the target cell is still not accessed, it means that the target cell access has failed. The second comparison execution unit is used to compare the cell handover command, the current location of the mobile terminal, and the second historical record when the mobile terminal subsequently receives a cell handover command. If the source cell, target cell, current location of the mobile terminal, and the source cell, target cell, and current location of the failed cell handover command corresponding to a timeout of the T304 timer in the second historical record are all the same, the timing duration of the T304 timer is reduced. The mobile terminal then uses the new timing duration to start the T304 timer and perform the cell handover process. If the T304 timer times out, it indicates that the cell handover has failed, and the mobile terminal initiates an RRC connection reconstruction process in the source cell.

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