WO2016169226A1

WO2016169226A1 - Heterogeneous system cell selecting method, device and base station

Info

Publication number: WO2016169226A1
Application number: PCT/CN2015/091866
Authority: WO
Inventors: 陈丹; 陈强
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-04-20
Filing date: 2015-10-13
Publication date: 2016-10-27
Also published as: CN106162783A

Abstract

A heterogeneous system cell selecting method, device and base station are provided in embodiments of the present invention. The selecting method includes: receiving a cell measurement result of a heterogeneous system cell transmitted from a terminal; selecting the optimal cell in each wireless communication mode according to the cell measurement result, in order to obtain an optimal cell list of different wireless communication modes; selecting the target cell for a handover according to the optimal cell list; and controlling the terminal to hand over to the target cell when it is necessary to perform a heterogeneous system cell handover for the terminal.

Description

Method, device and base station for selecting different system cells

Technical field

The embodiments of the present invention relate to, but are not limited to, the field of communications, and in particular, to a method, an apparatus, and a base station for selecting a different system cell.

Background technique

With the TD-LTE (Time Division-Long Term Evolution) technology and the terminal industry chain continue to mature and improve, including government agencies such as China Ministry of Information Industry, China Mobile, and China Telecom, mobile network operators Under the joint promotion of the LTE network, the wireless technology has already begun to be commercialized on a scale. VoLTE (Voice over LTE, Voice Long Term Evolution) is a voice service in the LTE (Long Term Evolution) network.

In the implementation of the VoLTE service, SRVCC (Single Radio Voice Call Continuity) is an important technical means to ensure the continuity of voice services, that is, when necessary, the voice service of the user terminal (UE) is used by other wireless systems ( Bearer with respect to LTE's heterogeneous system. For commercial users, in addition to the continuous demand for voice, there is also a need for voice quality.

Related technologies cannot better select a network with better signal quality to meet the needs of users.

Summary of the invention

The following is an overview of the topics detailed in this document. This Summary is not intended to limit the scope of the claims.

The embodiments of the present invention provide a method, a device, and a base station for selecting a different system cell, and selecting a better cell to improve the user experience.

The method for selecting a different system cell according to the embodiment of the present invention is applied to the network side, and the selection method includes:

Receiving a cell measurement result of a different system cell sent by the terminal;

Determining an optimal cell in each wireless communication system according to the measurement result of the cell, and obtaining an optimal cell list of different wireless communication systems;

And selecting, according to the optimal cell list, the target cell to be handed over, and controlling the terminal to switch to the target cell when performing the inter-system cell handover for the terminal.

Optionally, the selecting, by the optimal cell list, the target cell to be switched includes:

From the cells in the optimal cell list, any cell is selected or a cell with optimal signal performance is selected as the target cell.

Selecting a candidate cell from a cell in the optimal cell list;

Determining whether the candidate cell satisfies a preset terminal access condition, and obtains a determination result;

When the determination result is yes, the candidate cell is used as the target cell; when the determination result is no, the candidate cell is deleted from the optimal cell list, and the optimal When the current number of remaining cells in the cell list is greater than 0, the step of selecting the candidate cell from the cell in the optimal cell list is returned.

Optionally, the method for selecting the different system cell further includes:

When the current remaining cell number of the optimal cell list is 0, the entire process ends.

Optionally, the step of selecting a candidate cell from the cell in the optimal cell list includes:

Sorting the cells in the optimal cell list according to the performance of the different system signals, and obtaining the sorting result, wherein the different system signal performance includes the different system signal strength and the different system signal quality;

In the sorting result, an optimal candidate cell with the best performance of the different system signal is selected.

Optionally, the method further includes: after deleting the candidate cell from the optimal cell list, when the determining result is no, the method further includes:

When the current number of remaining cells in the optimal cell list is greater than 0, selecting the candidate system signal performance is lower than the candidate cell of the optimal candidate cell, until it is determined that the candidate cell has the access to switch the terminal. When the condition is met, the candidate cell is used as the target cell.

Correspondingly, the embodiment of the present invention further provides a device for selecting a different system cell, which is applied to the network side, and the selecting device includes:

a receiving module, configured to receive a cell measurement result of a different system cell sent by the terminal;

a selection module, configured to select an optimal cell in each wireless communication system according to the measurement result of the cell, to obtain an optimal cell list of different wireless communication systems;

The selection control module is configured to select a target cell to be switched according to the optimal cell list, and control the terminal to switch to the target cell when it is required to perform the inter-system cell handover for the terminal.

Optionally, the selection control module includes:

The first selection submodule is configured to select any cell from the cells in the optimal cell list or select a cell with optimal signal performance as the target cell.

Optionally, the selection control module includes:

a second selection submodule, configured to select a candidate cell from a cell in the optimal cell list;

a determining sub-module, configured to determine whether the candidate cell satisfies a preset terminal access condition, and obtain a determination result;

The processing submodule is configured to: when the determining result is yes, use the candidate cell as the target cell; when the determining result is no, the candidate cell is deleted from the optimal cell list, And when the current number of remaining cells in the optimal cell list is greater than 0, the second selection submodule is notified to perform an operation of selecting a candidate cell from the cell in the optimal cell list.

Optionally, the selection control module further includes:

The control submodule is configured to end the entire process when the current number of remaining cells in the optimal cell list is 0.

Optionally, wherein the second selection submodule comprises:

a sorting unit, configured to sort the cells in the optimal cell list according to the performance of the different system signal performance, and obtain a sorting result, wherein the different system signal performance includes the different system signal strength and the different system signal quality;

And a selecting unit, configured to select, in the sorting result, an optimal candidate cell with the best performance of the different system signal.

Optionally, the selection control module further includes:

Selecting a control submodule, configured to select, when the current number of remaining cells in the optimal cell list is greater than 0, selecting the candidate cell with the different system signal performance lower than the optimal candidate cell, until determining that the candidate cell has When the access condition of the terminal is switched, the candidate cell is used as a target cell.

Correspondingly, an embodiment of the present invention further provides a base station, including a device for selecting a different system cell as described above.

The embodiment of the invention further provides a computer readable storage medium storing program instructions, which can be implemented when the program instructions are executed.

In the solution of the embodiment of the present invention, the inter-system cell is sent to the terminal, and the terminal measures the cell, and then receives the cell measurement result sent by the terminal, and then selects the optimal under each wireless communication system in the cell measurement result. The cell obtains an optimal cell list for the optimal cell, and finally selects a cell belonging to the optimal cell list as the target cell to perform handover when the terminal needs to be handed over, so as to select a better cell and call the user. The quality experience has improved.

Other aspects will be apparent upon reading and understanding the drawings and detailed description.

BRIEF abstract

1 is a schematic diagram of basic steps of a method for selecting a different system cell according to an embodiment of the present invention;

2 is a schematic diagram of step 13 of a method for selecting a different system cell according to an embodiment of the present invention;

3 is a schematic diagram of overall steps of a method for selecting a different system cell according to an embodiment of the present invention;

4 is a schematic structural diagram of a device for selecting a different system cell according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a method for selecting a different system cell according to an embodiment of the present invention.

Embodiments of the invention

The embodiments will be described in detail below with reference to the accompanying drawings.

In the embodiment of the present invention, the best signal is selected from each wireless communication system, and then the optimal signal of the different system of different systems is selected to select the cell with the best signal performance for handover.

As shown in FIG. 1 , an embodiment of the present invention provides a method for selecting a different system cell, which is applied to a network side, and the selection method includes:

Step 11: Receive a cell measurement result of a different system cell sent by the terminal.

Step 12: Select an optimal cell in each wireless communication system according to the cell measurement result, and obtain an optimal cell list of different wireless communication systems.

Step 13: Select a target cell to be switched according to the optimal cell list, and control the terminal to switch to the target cell when it is required to perform inter-system cell handover for the terminal.

In the above steps 11 to 13, the hetero-system cell is sent to the terminal, and the terminal measures the cell, and then receives the cell measurement result sent by the terminal (step 11), and then selects each radio communication in the cell measurement result. The optimal cell in the system obtains an optimal cell list for the optimal cell (step 12), and finally, when the terminal needs to be handed over, the cell in the optimal cell list is selected as the target cell for handover (step 13). This selects a better cell and improves the user's call quality experience.

It should be noted that the above-mentioned different system refers to a wireless communication system that is different from the wireless communication system in which the terminal is currently located and does not belong to the LTE (Long Term Evolution) system.

For the embodiment of the present invention, the cell measurement result may be compared according to the performance of the signal to obtain an optimal cell in each wireless communication system.

The user service type of the terminal in the embodiment of the present invention is a VoLTE service.

In order to improve the call quality, in the method for selecting a different system cell in the embodiment of the present invention, step 13 includes:

Step 131: Select, from the cells in the optimal cell list, any cell or select a cell with optimal signal performance as the target cell.

In the embodiment of the present invention, when the terminal needs to be handed over, the cell that meets the terminal handover condition and belongs to the optimal cell list is selected as the target cell for handover, so that a better cell is selected according to the selection signal performance, and the call quality of the user is selected. The experience is improved and the user experience can be improved.

After the first choice of the best cell on the network side in the optimal cell list, it is necessary to judge whether the terminal can be switched. If it is not satisfied, the handover will be performed. If not, the communication will be interrupted. The effect of the user's experience is affected. Therefore, in the method for selecting a different system cell in the embodiment of the present invention, the network side needs to perform a reselection of a better cell, as shown in FIG.

Step 132: Select a candidate cell from a cell in the optimal cell list.

Step 133: Determine whether the candidate cell meets a preset terminal access condition, and obtain a determination result.

Step 134: When the determination result is yes, the candidate cell is used as the target cell; when the determination result is no, the candidate cell is deleted from the optimal cell list, and When the number of current remaining cells in the optimal cell list is greater than 0, the process returns to the cell in the optimal cell list, and the step of selecting the candidate cell is step 132.

In the embodiment of the present invention, the network side can interact with the terminal before the handover, and the network side can determine the cell condition that the terminal needs to access, and then the network side directly selects the best according to the cell and the access condition of the optimal cell list. The signal performance and the cell in which the terminal is switched, so that the terminal switching is not performed in the cell with the best signal performance but not suitable for the terminal, and the suitable and best cell is not directly sent to the handover command, thereby improving the switching efficiency. At the same time, by selecting the optimal signal performance and the selection of the cell of the appropriate terminal, the quality of the selected cell can also be improved, and the experience effect after the user switching can also be improved.

The implementation process of the embodiment of the present invention: transmitting a different system cell to the terminal for measurement, and then receiving the cell measurement result sent by the terminal (step 11), and then selecting the optimal cell in each wireless communication system in the cell measurement result, Obtaining an optimal cell list of the optimal cell (step 12), selecting a candidate cell (step 132), and when the candidate cell has the access condition of the terminal handover, the candidate cell is used as the target cell; When the access condition of the terminal handover is performed, the candidate cell is deleted from the optimal cell list, and the number of remaining cells in the optimal cell list is determined. When the current number of remaining cells in the optimal cell list is greater than 0, Then, the candidate cell can be selected from the cell in the optimal cell list, and the above step 132 is repeated (step 134), and finally, the cell that meets the terminal handover condition and belongs to the optimal cell list is selected as the target cell, and thus Multiple optimal signal performance and selection of cells suitable for the terminal can also improve the quality of the selected cell, and can also Experience after high user switching.

In addition, the foregoing access condition may be determined whether the candidate cell has a bearer capability for accessing the terminal, or may have a permission to allow the terminal to access, or may be the terminal itself. The access capability may also be a handover command that is issued when the terminal needs to switch to a different system when the terminal is at the edge of the LTE network. The step of controlling the terminal to switch to the target cell may be: the acquiring terminal sends a handover cell message, and then the network side receives the handover cell message sent by the terminal, the network side sends the target cell to the terminal, and finally the terminal continues in the target cell. Perform voice services.

In addition, the cell in the optimal cell list is a variable amount, and each time the cell is deleted, the non-compliant cells are deleted, and finally it is possible to judge all the cells in the optimal cell list.

If the cell in the measurement result does not meet the access requirement, the cell in the measurement result has been judged to be complete, and the entire process needs to be completed or the terminal does not need to perform cell handover. Therefore, the method for selecting a different system cell in the embodiment of the present invention is used. In step 13, step 13 further includes:

Step 135: When the current number of remaining cells in the optimal cell list is 0, the entire process ends.

In this embodiment, in order to prevent the network side from having a switchable terminal, it is necessary to end the entire process, and then the terminal may not be able to respond if the handover request is not sent, or may continue to perform step 11 to resend the hetero-system cell. The result of the cell measurement (it is possible that some cells have not received access due to congestion, and now the terminal can switch access). The simplest implementation method is that there is no need to switch without the target cell terminal, and the time for unnecessary interaction is reduced. The practicability of the embodiment of the present invention is improved, and the redundant action on the network side is also reduced.

Of course, there are multiple implementation manners for selecting a candidate cell from the cell in the optimal cell list:

Embodiment 1

1) selecting, from the cell in the optimal cell list, any cell as a candidate cell;

2) determining whether the candidate cell satisfies the access condition with the terminal handover, and determining the candidate cell as the target cell when the condition is met;

3) when the candidate cell does not have the access condition of the terminal handover, the candidate cell is deleted from the optimal cell list, and the number of remaining cells in the optimal cell list is determined;

4) When the number of the current remaining cells in the optimal cell list is greater than 0, the candidate cell may be selected from the cell in the optimal cell list, and the foregoing step 132 and step 133 of the embodiment of the present invention are repeatedly performed. And step 134, finally selecting the matching terminal switching condition and belonging to the optimal small The cell in the zone list serves as the target cell.

Embodiment 2

1) Sorting the cells in the optimal cell list according to the performance of the different system signal performance, and obtaining the sorting result, wherein the different system signal performance includes the different system signal strength and the different system signal quality;

2) selecting, in the sorting result, an optimal candidate cell with the best performance of the different system signal;

3) When the determination result is no, the candidate cell is deleted from the optimal cell list, and the number of remaining cells in the optimal cell list is determined:

4), when the current number of remaining cells in the optimal cell list is greater than 0, selecting the candidate system signal performance is lower than the candidate cell of the optimal candidate cell, until determining that the candidate cell has the terminal to switch When the condition is accessed, the candidate cell is used as a target cell. (In this case, the candidate cell whose signal performance is different from the optimal candidate cell in the different system is called the second candidate cell, and when the second candidate cell does not have the access condition for switching the terminal, the selection will be selected. The candidate system cell of the second candidate cell is called the third candidate cell, and the cell that is previously determined does not meet the terminal access condition, so until all the cells in the optimal cell list are determined The cell ends the entire process if there is no cell that meets the terminal access conditions.)

In the first embodiment and the second embodiment, when the current number of remaining cells in the optimal cell list is 0, the entire process ends. Of course, the above is only an example and is not intended to limit the invention.

For the first embodiment, by directly selecting any cell in the optimal cell list as the candidate cell, the time for selecting the candidate cell is saved. For the second embodiment, the optimal cell in different standards is followed. The signal performance is sorted, so that the cell with the best signal performance starts to find the target cell, and the target cell is found as soon as possible under the premise of the strongest signal performance, which reduces the number of repeated searches and improves the efficiency of selecting the target cell. Reduce the load on the network side.

The embodiment of the present invention can also avoid the problem that the cell with the best signal performance in the optimal cell in different systems can not be used, and find the next cell with good signal performance according to the sorting result, thereby improving the terminal switching. Feasibility, reducing the load on the network side.

For the user who performs the VoLTE service, the network side notifies the user terminal of the non-LTE network information, and the terminal performs signal quality measurement on multiple different systems while maintaining the service, and reports the measurement result. The network side judges the best signal by comprehensively evaluating the measurement results. When the handover condition is met, the best signal information is sent to the user terminal, and the handover is required, so that the user terminal switches to the best signal of non-LTE and continues the voice service. An example is as follows.

Example 1: In TD-LTE, WCDMA (Wideband Code Division Multiple Access) and GSM (Global System for Mobile Communication) hybrid networks, after LTE users initiate VoLTE services, they are in LTE. When the network edge needs to be switched to the different system, the selection method of the embodiment of the present invention can be used to optimize between the WCDMA network and the GSM network, so as to obtain the best call quality after the handover.

Example 2: In TD-LTE, TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) and GSM hybrid network, after the LTE user initiates the VoLTE service, at the edge of the LTE network, it needs to be different. When the system is switched, the selection method of the embodiment of the present invention can be used to optimize between the TD-SCDMA network and the GSM network, so as to obtain the best call quality after the handover.

As shown in FIG. 3, the method in the embodiment of the present invention enables a user who is a VoLTE service to use a wireless network with the best signal quality after a different handover in a wireless network adopting the TD-LTE technology, thereby obtaining an optimal call. An example of the overall implementation of quality is as follows.

Step S11: preparing;

Step S12: LTE (Long Term Evolution) user initiates a service;

Step S13: The network side determines whether the LTE user service is a VoLTE service, and when it is not a VoLTE service, restarts step S11;

Step S14: The network side sends the different system information to the user terminal UE;

Step S15: After receiving the different system information, the user terminal UE starts the heterogeneous system measurement;

Step S16: The user terminal UE reports the measurement result to the network side.

Step S17: The network side collects the measurement result of the UE, and selects the cell with the best signal performance in the same system;

Step S18: The network side stores the received measurement result, and between the optimal signals, determines an optimal signal screening and comparison, and determines an optimal signal;

Step S19: determining whether the switching condition of the different system is satisfied, and if not, returning to step 16;

Step S20: When different system switching needs to be performed, the network side selects the optimal signal related information to prepare the handover for the relevant network element;

Step S21: After the handover preparation is completed, the handover information of the target cell of the optimal signal is sent to the user terminal UE;

Step S22: The user terminal UE initiates a handover, and specifies a cell that is properly switched and has good signal performance, and continues the voice service;

Step S23: End.

Correspondingly, as shown in FIG. 4, an embodiment of the present invention provides a device for selecting a different system cell, which is applied to a network side, and the selecting device includes:

The receiving module 41 is configured to receive a cell measurement result of the different system cell sent by the terminal;

The selecting module 42 is configured to select an optimal cell in each wireless communication system according to the cell measurement result, to obtain an optimal cell list of different wireless communication systems;

The selection control module 43 is configured to select a target cell to be switched according to the optimal cell list, and control the terminal to switch to the target cell when it is required to perform inter-system cell handover for the terminal.

In the embodiment of the present invention, the hetero-system cell is sent to the terminal, and the terminal measures the cell, and then receives the cell measurement result sent by the terminal by the receiving module 41, and then the selecting module 42 selects each radio communication in the cell measurement result. The optimal cell in the system obtains an optimal cell list for the optimal cell. Finally, when it is necessary to switch for the terminal, the selection control module 43 selects the cell belonging to the optimal cell list as the target cell for switching, so that the selection is made. A good cell and an improvement in the user's call quality experience.

In the selection device of the different system cell of another embodiment, the selection control module 43 includes:

As shown in FIG. 5, in the selection device of the different system cell of another embodiment, the selection control module 43 includes:

The second selection submodule 431 is configured to select a candidate cell from the cell in the optimal cell list;

The determining sub-module 432 is configured to determine whether the candidate cell satisfies a preset terminal access condition, and obtain a determination result;

The processing sub-module 433 is configured to: when the determination result is yes, use the candidate cell as the target cell; when the determination result is no, delete the candidate cell from the optimal cell list. And when the current number of remaining cells in the optimal cell list is greater than 0, the second selection sub-module 431 is notified to continue to perform the step of selecting a candidate cell from the cell in the optimal cell list.

In the selection device of the different system cell of another embodiment, the selection control module 43 further includes:

In the selection device of the different system cell of another embodiment, the second selection submodule 431 includes:

It should be noted that, the apparatus provided by the embodiment of the present invention is a device that applies the foregoing method for selecting a different system cell, and all embodiments of the foregoing method for selecting a different system cell are applicable to the device, and both can achieve the same or similar Beneficial effect.

For convenience of understanding, the selection method and apparatus of the embodiments of the present invention are described in a wireless network using TD-LTE technology, but are not limited to a wireless network using TD-LTE technology, and may also be applied to FDD-LTE (Frequency division). In the wireless network of duplex-Long Term Evolution, frequency division duplex-long term evolution technology, here is not an example.

The embodiment of the invention further provides a base station, which comprises the selection device of the different system cell as described above.

The apparatus for selecting a different system cell according to the embodiment of the present invention is applied to the network side. Therefore, the embodiment of the present invention further provides a network side, where the implementation embodiments of the selecting apparatus of the different system cell are all The same technical effects can also be achieved in the embodiment applicable to the network side.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be accomplished by a program that instructs the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware or in the form of a software function module. Embodiments of the invention are not limited to any specific form of combination of hardware and software.

Industrial applicability

Claims

A method for selecting a different system cell is applied to the network side, and the selection method includes:

Receiving a cell measurement result of a different system cell sent by the terminal;

Determining an optimal cell in each wireless communication system according to the measurement result of the cell, and obtaining an optimal cell list of different wireless communication systems;

And selecting, according to the optimal cell list, the target cell to be handed over, and controlling the terminal to switch to the target cell when performing the inter-system cell handover for the terminal.
The selection method according to claim 1, wherein

The selecting a target cell to be switched according to the optimal cell list includes:

From the cells in the optimal cell list, any cell is selected or a cell with optimal signal performance is selected as the target cell.
The selection method according to claim 1, wherein

The selecting a target cell to be switched according to the optimal cell list includes:

Selecting a candidate cell from a cell in the optimal cell list;

Determining whether the candidate cell satisfies a preset terminal access condition, and obtains a determination result;

When the determination result is yes, the candidate cell is used as the target cell; when the determination result is no, the candidate cell is deleted from the optimal cell list, and the optimal When the current number of remaining cells in the cell list is greater than 0, the step of selecting the candidate cell from the cell in the optimal cell list is returned.
The selection method according to claim 3, further comprising:

When the current remaining cell number of the optimal cell list is 0, the entire process ends.
The selection method according to claim 3, wherein

The step of selecting a candidate cell from a cell in the optimal cell list includes:

Sorting the cells in the optimal cell list according to the performance of the different system signals, and obtaining the sorting result, wherein the different system signal performance includes the different system signal strength and the different system signal quality;

In the sorting result, an optimal candidate cell with the best performance of the different system signal is selected.
The method according to claim 5, wherein after the determining result is negative, after the candidate cell is deleted from the optimal cell list, the method further includes:

When the current number of remaining cells in the optimal cell list is greater than 0, selecting the candidate system signal performance is lower than the candidate cell of the optimal candidate cell, until it is determined that the candidate cell has the access to switch the terminal. When the condition is met, the candidate cell is used as the target cell.
A device for selecting a different system cell is applied to the network side, and the selecting device includes:

a receiving module, configured to receive a cell measurement result of a different system cell sent by the terminal;

a selection module, configured to select an optimal cell in each wireless communication system according to the measurement result of the cell, to obtain an optimal cell list of different wireless communication systems;

The selection control module is configured to select a target cell to be switched according to the optimal cell list, and control the terminal to switch to the target cell when it is required to perform the inter-system cell handover for the terminal.
The selection device according to claim 7, wherein the selection control module comprises:

The first selection submodule is configured to select any cell from the cells in the optimal cell list or select a cell with optimal signal performance as the target cell.
The selection device according to claim 7, wherein the selection control module comprises:

a second selection submodule, configured to select a candidate cell from a cell in the optimal cell list;

a determining sub-module, configured to determine whether the candidate cell satisfies a preset terminal access condition, and obtain a determination result;

The processing submodule is configured to: when the determining result is yes, use the candidate cell as the target cell; when the determining result is no, the candidate cell is deleted from the optimal cell list, And when the current number of remaining cells in the optimal cell list is greater than 0, the second selection submodule is notified to perform an operation of selecting a candidate cell from the cell in the optimal cell list.
The selection device according to claim 9, wherein the selection control module further comprises:

The control submodule is configured to end the entire process when the current number of remaining cells in the optimal cell list is 0.
The selection device according to claim 9, wherein the second selection sub-module comprises:

a sorting unit, configured to sort the cells in the optimal cell list according to the performance of the different system signal performance, and obtain a sorting result, wherein the different system signal performance includes the different system signal strength and the different system signal quality;

And a selecting unit, configured to select, in the sorting result, an optimal candidate cell with the best performance of the different system signal.
The selection device according to claim 11, wherein the selection control module further comprises:

Selecting a control submodule, configured to select, when the current number of remaining cells in the optimal cell list is greater than 0, selecting the candidate cell with the different system signal performance lower than the optimal candidate cell, until determining that the candidate cell has When the access condition of the terminal is switched, the candidate cell is used as a target cell.
A base station comprising the apparatus for selecting a different system cell according to any one of claims 7 to 12.
A computer readable storage medium storing program instructions that, when executed, can implement the method of any of claims 1-6.