CN101572927A - Cell reselection method, apparatus and system thereof - Google Patents

Abstract

The invention discloses a cell reselection method, equipment and system, relates to wireless communication technology, can reduce the time delay of service restart in the target cell after the cell reselection occurs, and accelerate the process of the next cell reselection. The cell reselection method provided by the embodiment of the present invention includes: after the cell reselection occurs, synchronizing the terminal to the target cell, and restarting the communication service in the target cell according to the cell reselection information saved before the cell reselection occurs. The present invention is applicable to any scene where cell reselection is required.

Description

Cell reselection method, device and system

technical field

The present invention relates to wireless communication technology, in particular to a cell reselection method, device and system.

Background technique

A feature of Global System for Mobile Communications (GSM, Global System for Mobile Communications), General Packet Radio Service (GPRS, General Packet Radio Service) cellular communication mobile system is that during a communication call, a mobile terminal can be connected to a cell of the mobile communication system. Moving to another cell, a process known as "handover" and "cell reselection" can take place.

When performing cell reselection, according to the power levels of the serving cell and its neighbors received by the mobile terminal, and the parameters received on the broadcast control channel (BCCH, Broadcast Control Channel) of the serving cell and its neighbors (the parameters Exist in system information 3 or 4) Calculate the value of the cell reselection criterion C2 (Cell Reselection Criterion), and then select the target cell based on the C2 value, and trigger the corresponding cell reselection process by the mobile terminal or the network.

The processing flow of cell reselection in the prior art, as shown in Figure 1, when a mobile terminal resides under a cell (serving cell) of GPRS, the mobile terminal must periodically measure the power levels of the serving cell and all its neighbors. Ping, and read system messages affecting cell reselection of the serving cell and all neighboring cells, such as system message 3 or 4. Calculate the C2 value of the serving cell and its neighboring cells based on the power level and system information. When the C2 value of a certain neighboring cell is greater than the C2 value of the serving cell for more than 5 seconds, cell reselection will be initiated and the neighboring cell will be reselected. The target cell for cell reselection.

Once cell reselection is triggered, the mobile terminal first synchronizes to the target cell, then the mobile terminal reads the necessary system information (such as system information 1, 3 or 4, 13, etc.) of the target cell, and restarts the GPRS service in the target cell. The target cell is the current serving cell. The mobile terminal will continue to read the necessary system information affecting cell reselection of the neighboring cells of the target cell, and calculate the C2 value of the neighboring cells, etc., to perform the next cell reselection.

It can be known from the above that in the prior art, from triggering cell reselection to restarting GPRS service in the target cell, it is necessary to temporarily interrupt the GPRS communication service. After the cell reselection occurs, the mobile terminal needs to read the corresponding system information of the target cell to restart the GPRS service in the target cell.

In the process of realizing the present invention, the inventor found that the prior art has at least the following problems: since the target cell is selected from the neighboring cells of the original serving cell, the mobile terminal has read the original serving cell before cell reselection occurs. Corresponding system information of adjacent cells, such as system information 3 or 4, in the prior art, the mobile terminal needs to repeatedly read the same system information of the same cell, which increases the power consumption of the mobile terminal, and also increases the number of reads after cell reselection occurs. The time delay of the system message in the target cell leads to a long interruption time of the GPRS service and poor user experience.

Contents of the invention

In order to solve the problems existing in the prior art, the embodiments of the present invention provide a cell reselection method, device and system.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

An embodiment of the present invention provides a cell reselection method, the method comprising:

After cell reselection occurs, synchronize the terminal to the target cell;

The communication service is restarted in the target cell according to the cell reselection information saved before the cell reselection occurs.

An embodiment of the present invention provides a mobile terminal, including:

a synchronization unit, configured to synchronize the terminal to the target cell after cell reselection occurs;

The service restart unit is configured to restart the communication service in the target cell synchronized by the synchronization unit according to the cell reselection information saved before the cell reselection occurs.

An embodiment of the present invention also provides a communication system, which includes the above-mentioned mobile terminal.

The technical solution provided by the embodiment of the present invention significantly reduces the trouble caused by reading the cell reselection information of the target cell after the cell reselection occurs by obtaining and saving the cell reselection information of the target cell in advance before cell reselection. Service restart time delay enhances user experience.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic diagram of the processing flow of cell reselection in the prior art;

FIG. 2 is a schematic flow chart of a cell reselection method provided by Embodiment 1 of the present invention;

FIG. 3 is a schematic flowchart of another cell reselection method provided by Embodiment 1 of the present invention;

FIG. 4 is a schematic flowchart of a cell reselection method provided in Embodiment 2 of the present invention;

FIG. 5 is a schematic diagram of the principle of saving the system information of the serving cell and its neighboring cells according to Embodiment 2 of the present invention;

FIG. 6 is a manner of predicting a target cell provided in Embodiment 2 of the present invention;

FIG. 7 is another way of predicting a target cell provided in Embodiment 2 of the present invention;

FIG. 8 is a schematic structural diagram of a mobile terminal provided by Embodiment 3 of the present invention;

FIG. 9 is a schematic structural diagram of another mobile terminal provided by Embodiment 3 of the present invention;

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

The embodiment of the present invention provides a method applicable to a GPRS network or an enhanced GPRS (EGPRS, EnhanceGPRS) network to reduce service restart delay and accelerate cell reselection. But not limited thereto, it can also be applied in other types of networks or scenarios.

In the embodiment of the present invention, the cell reselection information mainly includes system messages necessary for cell reselection, such as system message 1, system message 3 or system message 4, system message 13, but is not limited to this, and also includes other Necessary information for cell reselection. The cell assessment information mainly includes the system information needed when predicting or selecting the target cell for cell reselection, such as system message 3 or system message 4, but is not limited to this, and may also include other information when predicting or selecting the target cell for cell reselection. required information.

The following is a brief introduction to the specific content and functions of the system messages. For example, in the GPRS system, each base station broadcasts the system information of the base station on the BCCH. System messages include cell reselection parameters and information necessary for mobile terminals to establish services. The BCCHs of adjacent base stations transmit signals on different frequencies, so that the mobile terminal can distinguish each base station conveniently. The mobile terminal calculates the received power level of each cell by measuring the signal strength of the BCCH of each base station. In addition, the system message of the serving cell of the mobile terminal broadcasts information such as the frequency point of the BCCH of each neighboring cell (such as the list of neighboring cells) to the mobile terminal at the same time, so that the mobile terminal can measure the power level of these neighboring cells, and synchronize and read the neighbor cells. System messages for the zone. Therefore, the cell reselection information and cell evaluation information in the embodiment of the present invention mainly consider necessary system information.

The cell reselection method provided by Embodiment 1 of the present invention, as shown in FIG. 2 , includes the following steps:

Step 21: After cell reselection occurs, synchronize the terminal to the target cell;

Step 22: Restart the communication service in the target cell according to the cell reselection information saved before the cell reselection occurs.

In Embodiment 1 of the present invention, the terminal may obtain the above cell reselection information in various ways, for example, as shown in FIG. 3, may include the following processing:

Step S1: Before cell reselection occurs, the mobile terminal predicts the target cell where cell reselection will occur;

Step S2: the mobile terminal reads and saves the cell reselection information of the target cell;

Step S3: After the cell reselection occurs, the mobile terminal restarts the communication service in the target cell according to the stored cell reselection information.

Alternatively, the terminal may obtain the above cell reselection information in the following manner: the mobile terminal reads and saves the cell reselection information of all pre-selected target cells in advance before cell reselection occurs, and the pre-selected target cells are likely to be handed over to by the mobile terminal The cells of the target cell, such as the six strongest neighboring cells of the current serving cell. When cell reselection occurs, if the reselected cell is a cell in the preselected target cell, the mobile terminal can read the cell reselection information of the target cell from the locally saved cell reselection information of the preselected target cell, so as to facilitate Restart the business.

In the technical solution provided by Embodiment 1 of the present invention, by reading and saving the cell reselection information of the target cell in advance before the cell reselection, it significantly reduces the trouble caused by reading the cell reselection information of the target cell after the cell reselection occurs. Incoming service restart delay is enhanced, which enhances user experience.

The cell reselection method provided by Embodiment 2 of the present invention is introduced below.

In the technical solution provided by Embodiment 2 of the present invention, the mobile terminal saves the system information of the serving cell and its neighboring cells that affect cell reselection during communication with the serving cell, and reads in advance in a targeted manner by reasonably predicting the target cell for cell reselection. Fetch and store the system information necessary for cell reselection in the target cell, reducing the service restart delay caused by reading the system information of the cell after cell reselection.

Further, when the cell reselection is completed, the mobile terminal can quickly calculate the value of the cell reselection criterion C2 of each neighboring cell by using the stored system information of some neighboring cells of the current serving cell, so as to speed up the next cell reselection the process of.

The cell reselection method provided by Embodiment 2 of the present invention specifically includes the following steps, as shown in FIG. 4 .

Step T1: Under the current serving cell, the mobile terminal saves the cell evaluation information of the serving cell and its neighboring cells that affect cell reselection.

Exemplarily, the cell assessment information may be system message 3 or system message 4.

Optionally, the neighboring cells of the serving cell in this embodiment of the present invention refer to the six strongest neighboring cells of the serving cell. Exemplarily, the embodiment of the present invention saves the cell evaluation information of the serving cell and its six strongest neighbor cells, and the method shown in Figure 5 can be used, including:

Step 511: save the system message 3 or system message 4 of the serving cell;

For the serving cell, when the terminal reads the system message 3 or 4 of the serving cell for the first time, the terminal saves the system message locally.

Step 512: Determine whether the system information of the serving cell is updated;

For example, by periodically reading the system information 13 of the serving cell, it is judged whether the system information 3 or 4 of the serving cell is updated.

Step 513: If the system information is updated, re-read the system information 3 or 4 of the serving cell and save it;

If the current system message is not updated, save the last acquired system message 3 or 4.

For the neighboring cells of the above-mentioned serving cell, the following methods can be used to read the cell evaluation information of the neighboring cells:

Step 521: Save the system information 3 or 4 of each neighboring cell of the serving cell.

For example, for the 6 strongest neighboring cells of the serving cell, periodically read and save the system information 3 or 4 of the current 6 strongest neighboring cells, where the last read system information is overwritten and saved Received system messages.

After obtaining the cell evaluation information, the mobile terminal can use the cell evaluation information to predict the target cell, and read the system information required by the target cell for restarting services in advance, so as to speed up the process of restarting services after cell reselection. Still refer to Figure 5, which specifically includes:

Step 522: Predict the target cell;

For the prediction method of the target cell, refer to the relevant descriptions in FIG. 6 and FIG. 7 .

Step 523: Read and save system information necessary for service restart in the target cell.

Through step 523, the cell reselection information of the target cell can be read in advance. The cell reselection information necessary for the restart may be system messages 1 and 3 or system messages 4 and 13 .

Wherein, the operation of reading and saving the system information of the serving cell in step 511 and the operation of reading and saving the system information of the neighboring cell of the serving cell in step 521 can be performed simultaneously, but the periods of reading the system information of the two can be different, For example, the interval for reading the system information of the serving cell may be 30 seconds or more, and the interval for reading the system information of the neighboring cell may be 5 minutes or more.

Step T2: Predict whether there is a neighboring cell meeting the requirements of the target cell according to preset logic.

According to the acquired cell evaluation information or received power levels of the serving cell and its neighboring cells (the mobile terminal can quickly obtain the received power levels of each neighboring cell), predict the target cell where reselection occurs. Exemplarily, the method for predicting the target cell for which reselection will occur may adopt the following two methods:

Referring to Figure 6, it shows a way of predicting the target cell, which way includes:

Step 61: Judging whether the received power level of a neighboring cell of the current serving cell is greater than a predetermined threshold. Optionally, the predetermined threshold may be -70dbm.

Step 62: If the received power level of a certain neighboring cell of the current serving cell is greater than a predetermined threshold, predict that the neighboring cell is the target cell; predict.

Optionally, other conditions can be used for prediction, such as when the difference between the received power level of a certain neighboring cell of the serving cell and the received power level of the serving cell is greater than a certain predetermined threshold, such as the predetermined threshold can be The received power level of the neighboring cell is subtracted by 10, and the neighboring cell is predicted to be the target cell; otherwise, continue to judge whether there is a neighboring cell satisfying the condition, and perform the prediction operation of the target cell. The predetermined thresholds of the above two methods may be the same or different.

Referring to Fig. 7, another way of predicting the target cell is shown, which way includes:

Step 71: Judging whether the difference between the C2 value of a certain neighboring cell of the serving cell and the C2 value of the serving cell is greater than a predetermined threshold.

An appropriate predetermined threshold may be selected as required, for example, the predetermined threshold may be 0, -5, 5, and so on.

Step 72: When the difference between the C2 value of a neighboring cell of the serving cell and the C2 value of the serving cell is greater than a predetermined threshold, predict that the neighboring cell is the target cell.

For example, when the predetermined threshold is zero, that is, when the C2 value of a certain neighboring cell of the serving cell is greater than the C2 value of the serving cell, it is predicted that the neighboring cell is the target cell (the cell reselection has been started at this time). Otherwise, continue to judge whether there is a neighboring cell satisfying the condition, and perform the prediction operation of the target cell.

Step T3: When the target cell is predicted, start reading the necessary system information (such as system information 1, 3 or system information 4, 13, etc.) related to service restart of the target cell in advance.

It can be seen from the above that when reading the cell evaluation information of the neighboring cell of the serving cell in step T1, the system information 3 or 4 of the target cell has been read, and here the system information 3 or 4 of the target cell is re-read , mainly considering that the system information of the target cell may change. Although the probability of such a change is low, in order to ensure that the latest system information is obtained to ensure that the communication service is successfully restarted after the subsequent cell reselection occurs, here, Read and save the system information 1, 3 or 4, 13 of the target cell in advance.

Since there is a delay of at least 5 seconds from the initiation of target cell evaluation to the occurrence of cell reselection, the mobile terminal has sufficient time to read the system information necessary for the service restart of the target cell.

Step T4: judging whether cell reselection occurs;

When the cell reselection is triggered by the mobile terminal, when the mobile terminal measures that the C2 value of a certain neighboring cell is greater than the C2 value of the serving cell, the cell reselection evaluation is started. In order to prevent the ping-pong phenomenon in the cellular communication system, the C2 value of the neighboring cell must be greater than the C2 value of the serving cell for a predetermined time, such as at least 5 seconds, before the mobile terminal initiates the cell reselection process.

Step T5: After the cell is reselected, it is judged whether the system information 3 or 4 of the target cell is updated.

After cell reselection, the terminal is first synchronized to the target cell.

In step T5, by reading the system information 13 of the target cell, it can be judged whether the system information 3 or 4 has been updated before and after cell reselection. This operation is also to ensure that the latest system information of the target cell is obtained.

Step T6: If the system information of the target cell has been updated before and after cell reselection, re-read the system information necessary for service restart;

In a cellular communication system, the probability of updating system messages is low, and the probability of re-reading system messages is also very low. In most cases, the mobile terminal can directly use the saved system information of the target cell before the cell reselection occurs.

Step T7: Restart the service.

Use the latest system information of the target cell obtained in the above process to restart the service in the target cell. After the service is restarted, the target cell provides services for the mobile terminal, and the target cell becomes the current serving cell.

Step T8: Maintain the neighbor cells of the target cell (current serving cell).

Use the saved system information, the neighbor list of the original serving cell (the last served cell), and the neighbor list of the target cell (the current serving cell) to quickly maintain the neighbors of the target cell. The neighbor list register can be set to save the serving cell and all its neighbor list information. In the embodiment of the present invention, the neighboring cells of the serving cell and the target cell refer to the six strongest neighboring cells of the serving cell and the target cell.

In step T8, predict the target cell or trigger cell reselection according to the neighboring cells of the current serving cell, the last serving cell and its neighboring cells, and the saved cell evaluation information of the last serving cell and its neighboring cells, Thereby speeding up the process of the next cell reselection, specifically including the following processing:

For the neighboring cells of the current serving cell, which are the same as the last serving cell and its neighboring cells, use the saved cell evaluation information of the last serving cell and its neighboring cells, such as system message 3 or 4, to predict the Target cell or trigger cell reselection. For example, if cell 1 is both the neighbor of the current serving cell and the neighbor of the last serving cell, the saved system information of cell 1 will be used preferentially; when the last serving cell is also a neighbor of the current serving cell, the System information of the last serving cell that has been saved.

For the adjacent cells of the current serving cell that are different from the previous serving cell and its adjacent cells, re-read the cell evaluation information of the adjacent cell, and use the re-read cell evaluation information to predict the target cell or Trigger cell reselection.

Considering that the system information can change, for the neighboring cells of the current serving cell, which are the same as the serving cell and its neighboring cells last time, when it is judged that the system information of the neighboring cell has changed, read the information of the neighboring cell again. The cell evaluation information uses the re-read cell evaluation information to predict the target cell or trigger cell reselection.

After a cell reselection is completed, the C2 value of each neighboring cell of the current serving cell can be quickly calculated by using the saved cell evaluation information of the neighboring cell of the serving cell, such as system message 3 or 4, through the above operations, and the C2 value can be used to Predict the target cell or use the C2 value to compare with the current serving cell to trigger cell reselection, thereby speeding up the process of next cell reselection.

Embodiment 3 of the present invention also provides a mobile terminal, as shown in FIG. 8 , including:

The synchronization unit 81 is configured to synchronize the terminal to the target cell after cell reselection occurs.

The service restart unit 82 is configured to restart the communication service in the target cell synchronized by the synchronization unit 81 according to the cell reselection information saved before the cell reselection occurs.

The mobile terminal can predict the target cell where cell reselection will occur before the cell reselection occurs, read and save the cell reselection information of the target cell, and after the cell reselection occurs, the mobile terminal uses the service restart unit 82 according to The saved cell reselection information restarts the communication service in the target cell. Or, before the cell reselection occurs, the mobile terminal reads and saves the cell reselection information of all preselected target cells in advance, and the preselected target cell is the cell most likely to be the target cell to which the mobile terminal is handed over, such as 6 of the current serving cell. the strongest neighbor. When cell reselection occurs, the mobile terminal uses the service restart unit 82 to read the cell reselection information of the target cell from the stored cell reselection information of each preselected target cell.

Further, as shown in FIG. 9, the mobile terminal above also includes:

A predicting unit 83, configured to predict a target cell where cell reselection will occur.

The obtaining and saving unit 84 is configured to obtain and save the cell reselection information of the target cell predicted by the prediction unit.

The service restart unit 82 is configured to restart the communication service in the target cell synchronized by the synchronization unit 81 according to the cell reselection information saved by the acquisition and storage unit 84 before the cell reselection occurs.

Wherein, the above prediction unit 83 can predict the target cell in various ways, for example, when the prediction unit 83 judges that the received power level of a certain neighboring cell of the current serving cell is greater than a predetermined threshold, it predicts that the neighboring cell is the target cell, or When the prediction unit 83 judges that the difference between the C2 value of a certain neighboring cell of the serving cell and the C2 value of the serving cell is greater than a predetermined threshold, it predicts that the neighboring cell is the target cell.

Further, the above-mentioned mobile terminal may also include:

A reselection processing unit, configured to predict the target cell or trigger cell reselection according to the neighbors of the current serving cell, the last serving cell and its neighbors, and the saved cell evaluation information of the last serving cell and its neighbors select. For example, when the reselection processing unit knows that cell 1 is both the neighbor cell of the current serving cell and the neighbor cell of the last serving cell, it will preferentially use the saved system information of cell 1; When the cell is a neighboring cell, the saved system information of the serving cell last time is given priority.

When storing the above-mentioned cell reselection information, the cell evaluation information of the serving cell and its neighbors last time, the information can be stored in one or more functional modules of the above-mentioned mobile terminal, or can be stored in a different function module than the above-mentioned functional modules. in the storage module. Exemplarily, a storage module may be set in the acquisition and storage unit 84 to store cell reselection information of the target cell, such as system messages 1, 3 or 4, 13. A storage module can be set in the reselection processing unit to store the last cell evaluation information of the serving cell and its neighboring cells, such as system messages 1, 3 or 4, 13. A separate system message register can also be set to store the last cell evaluation information of the serving cell and its neighboring cells, as well as the cell reselection information of the target cell.

A separate neighbor list register can be set to save the serving cell itself and its neighbor list, or the serving cell and its neighbor list can be stored in the storage module of the reselection processing unit.

Further, the service restart unit 82 also includes an update processing module, configured to determine that the cell reselection information of the target cell has been updated after cell reselection occurs, and re-read the cell reselection information of the target cell, according to The re-read cell reselection information restarts the communication service in the target cell; if no update occurs, restarts the communication service in the target cell according to the saved cell reselection information.

An embodiment of the present invention also provides a communication system, including the above-mentioned mobile terminal.

The technical solution provided by the embodiment of the present invention: during the communication with the serving cell, the mobile terminal saves the system information of the serving cell and its neighboring cells that affect cell reselection, and reads in advance in a targeted manner by reasonably predicting the target cell for cell reselection and save the system information necessary for cell reselection in the target cell, reducing the service restart delay caused by reading the system message after cell reselection; further, when the cell reselection is completed, use the saved current serving cell The system information of some neighboring cells can be used to quickly calculate the value of the cell reselection criterion C2 of each neighboring cell, so as to speed up the process of the next cell reselection.

Those skilled in the art can clearly understand that the present invention can be realized by means of software plus necessary general hardware platform. Based on such an understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art can be embodied in the form of software products, and the computer software products can be stored in storage media, such as ROM/RAM, disk, The CD, etc., includes several instructions to make a computer device (which may be a personal computer, server, or network device, etc.) execute the methods described in various embodiments or some parts of the embodiments of the present invention.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (12)

1. A cell reselection method, characterized in that the method comprises: After cell reselection occurs, synchronize the terminal to the target cell; The communication service is restarted in the target cell according to the cell reselection information saved before the cell reselection occurs. 2. The method according to claim 1, wherein after the cell reselection occurs, before synchronizing the terminal to the target cell, further comprising: Before cell reselection occurs, predict the target cell where cell reselection will occur; acquiring and saving the cell reselection information of the target cell; or, Before cell reselection occurs, cell reselection information of all preselected target cells is acquired and saved. 3. The method according to claim 1, wherein the restarting the communication service in the target cell according to the saved cell reselection information before the cell reselection occurs comprises: When the cell reselection information of the target cell is updated, the cell reselection information of the target cell is reacquired, and the communication service is restarted in the target cell according to the reacquired cell reselection information. 4. The method according to claim 1, wherein the prediction of the target cell where cell reselection will occur comprises: If the received power level of the first neighboring cell of the current serving cell is greater than a predetermined threshold, using the first neighboring cell as a target cell; or, If the difference between the received power level of the first neighboring cell of the current serving cell and the received power level of the current serving cell is greater than a predetermined threshold, using the first neighboring cell as a target cell; or, If the difference between the cell reselection criterion C2 value of the first neighboring cell of the current serving cell and the C2 value of the current serving cell is greater than a predetermined threshold, the first neighboring cell is used as a target cell. 5. The method according to claim 1, further comprising: Predict the target cell or trigger cell reselection according to the neighboring cells of the current serving cell, the last serving cell and its neighboring cells, and the saved cell evaluation information of the last serving cell and its neighboring cells. 6. The method according to claim 5, characterized in that, according to the neighbors of the current serving cell and the neighbors of the last serving cell, and the saved cell evaluation information of the last serving cell and its neighbors, Predicting the target cell or triggering cell reselection includes: For the neighboring cells of the current serving cell, which are the same as the last serving cell and its neighboring cells, use the saved cell evaluation information of the last serving cell and its neighboring cells to predict the target cell or trigger cell reselection ; For the neighboring cells of the current serving cell that are different from the previous serving cell and its neighboring cells, reacquire the cell evaluation information of the neighboring cells, and use the reacquired cell evaluation information to predict the target cell or trigger cell re-election. 7. The method according to claim 5, characterized in that, according to the neighbors of the current serving cell and the neighbors of the last serving cell, and the saved cell evaluation information of the last serving cell and its neighbors, Predicting the target cell or triggering cell reselection also includes: Among the neighboring cells of the current serving cell, which are the same as the last serving cell and its neighboring cells, reacquire the cell evaluation information of the neighboring cell, and use the reacquired cell evaluation information to predict the target cell or trigger cell re-acquisition select. 8. A mobile terminal, characterized in that it comprises: a synchronization unit, configured to synchronize the terminal to the target cell after cell reselection occurs; The service restart unit is configured to restart the communication service in the target cell synchronized by the synchronization unit according to the cell reselection information saved before the cell reselection occurs. 9. The mobile terminal according to claim 8, further comprising: A prediction unit, configured to predict a target cell where cell reselection will occur; An acquisition and storage unit, configured to acquire and store the cell reselection information of the target cell predicted by the prediction unit; The service restart unit is specifically configured to restart the communication service in the target cell synchronized by the synchronization unit according to the cell reselection information stored by the acquisition and storage unit before the cell reselection occurs. 10. The mobile terminal according to claim 8, wherein the service restart unit further includes an update processing module, configured to reacquire the information of the target cell when the cell reselection information of the target cell is updated. Cell reselection information, restarting communication services in the target cell according to the reacquired cell reselection information. 11. The mobile terminal according to claim 8, further comprising: A reselection processing unit, configured to predict the target cell or trigger cell reselection according to the neighbors of the current serving cell, the last serving cell and its neighbors, and the saved cell evaluation information of the last serving cell and its neighbors select. 12. A communication system, characterized in that the system comprises the mobile terminal according to any one of claims 8-11.

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