Abstract:
The present invention relates to a method and an equipment for controlling the mobile station to switch between different wireless communication systems and belongs to the technical field of data transmission in the wireless communication systems. In order to resolve the problem that there are no means in the prior art to effectively control the mobile station to switch between different wireless communication systems at specified position, the present invention uses different network identifications to distinguish different wireless communication systems, and a set of wireless transceiver modules is mounted on the mobile station to associate with wireless communication system, and a set of independent receiving modules is mounted to receive the switch command from the ground sending device, the ground sending device sends the switch command when the mobile station passes the switching point; after receiving this switch command, the mobile station modifies its network identification according to the network identification comprised in the switch command for the target switching wireless communication system, and cuts off the link with the current wireless communication system and establishes the link with the target switching wireless communication system. This solution could realize the controlled switching for the mobile station between multiple overlapping wireless communication systems, and reduce the rate of wrong switching.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is a U.S. National Phase Application under 35 U.S.C. §371 of International Application No. PCT/CN2011/001254, filed Aug. 1, 2011, entitled METHOD AND EQUIPMENT FOR CONTROLLING MOBILE STATION TO SWITCH BETWEEN DIFFERENT WIRELESS COMMUNICATION SYSTEMS, which claims priority to Chinese Patent Application No. 201010245275.3, filed Aug. 4, 2010. 
     TECHNICAL FIELD 
     The present invention relates to data transmission technology used in the wireless communication system, and in particular to a method and equipment for controlling mobile station to switch between different wireless communication systems. 
     BACKGROUND ART 
     In application, a mobile station is required to be controlled at the specified position for switching from one wireless communication system to another specified wireless communication system, and then communicates with the equipment connected with the aforesaid specified wireless communication system; the wireless communication system before and after switching may share the same backbone network, or may be connected to different backbone networks. 
     As shown in  FIG. 1 , the direction of the movement of the mobile station is indicated by an arrow in  FIG. 1 . Mobile station is required to be associated with wireless communication system  1  before reaching point A, at this time the data is transmitted between terminal K and terminal M by means of wireless network  1  and backbone network  1 ; the mobile station is required to be associated with wireless communication system  2  when reaching point A, at this time the data is transmitted between terminal K and terminal M by means of wireless network  2  and backbone network  1 ; the mobile station is required to be associated with wireless communication system  3  when reaching point B, at this time the data is transmitted between terminal K and terminal N by means of wireless network  3  and backbone network  2 . 
     When compared with the current signal intensity received, the signal intensity received from another wireless communication system by mobile station is higher enough to reach a specified threshold value, the mobile station will choose to switch to the said wireless communication system. Because the mobile station randomly receives the wireless signal, at any point within the overlapping region of wireless communication system  1  and wireless communication system  2 , it is possible for the mobile station to switch between wireless communication system  1  and wireless communication system  2  when moving in the direction as indicated by the arrow in  FIG. 1 ; for the same reason, at any point within the overlapping region of wireless communication system  2  and wireless communication system  3 , it is also possible for the mobile station to switch between wireless communication system  2  and wireless communication system  3 . There is no effective means at the present for controlling the mobile station to switch to a specified wireless communication system at a specified position. 
     SUMMARY 
     The Technical Problem to be Resolved 
     The objective of the present invention is to resolve the problem that there is no effective means in the prior art for controlling the mobile station to switch at a specified point between different wireless communication systems, and to realize the controlled switch between multiple overlapping wireless communication systems. 
     Technical Solution 
     To resolve the problem said above, the present invention provides a method for controlling the mobile station to switch between different wireless communication systems, the said method comprising: 
     step 1 setting different network identifications respectively for multiple wireless communication systems involved in the communication process; setting the same network identification for the mobile station and the wireless communication system specified to be linked with the mobile station; 
     step 2 mounting ground sending device at the specified switching position; 
     step 3 the said ground sending device sending the switch command to the mobile station when the mobile station passes the specified switching position; the said switch command comprising the network identification for the current wireless communication system; 
     step 4 after receiving the switch command, the mobile station determining whether its network identification is the same as that comprised in the switch command for the current wireless communication system; if they are the same, the mobile station modifies its network identification according to the switch command; 
     step 5 the mobile station cutting off the link with the current wireless communication system; 
     step 6 the mobile station establishing the link with the target wireless communication system. 
     Wherein the said method further comprising the following prior to step 3, an independent receiving device for switch command is mounted at the mobile station, which is used for receiving the switch command sent by the ground sending device. 
     The said switch command comprises the network identification for the target switching wireless communication system. 
     Wherein the details of step 4 comprising are as follow: 
     step 4.1 after receiving the switch command, the mobile station would determine whether the network identification comprised in the switch command for the current wireless communication system is the same as that for the mobile station itself; 
     step 4.2 if the comparison result of step 4.1 is they are the same, the mobile station would modify its network identification; if the comparison result of step 4.1 is they are not the same, the mobile station would terminate the subsequent switching operation. 
     In the said step 4, after receiving the switch command, the mobile station modifies its network identification to the one comprised in the said switch command for the target switching wireless communication system. 
     In addition, an equipment for controlling the mobile station to switch between different wireless communication systems is further provided by the present invention, comprising: 
     wireless transceiver module, which is used for establishing association with the wireless communication system, receiving the business data sent by ground sending device via the wireless communication system, and sending the business data to the control module, the business data sent by the control module to the wireless communication system simultaneously; it is also used to receive the switch instruction from the control module and set the network identification for the mobile station itself according to the switch instruction; 
     independent receiving module for switch command, which is used to receive the switch command sent by the ground sending device and transmit the switch command to the control module; 
     control module, which is used to receive the business data transmitted by the wireless transceiver module and send the business data to the wireless transceiver module; it is also used to receive the switch command transmitted by the independent receiving module and determine whether the network identification for the mobile station is the same as that comprised in the switch command for the current wireless communication system, and send the switch instruction to the said wireless transceiver module according to the said switch command if they are the same. 
     Wherein, said control module comprising: 
     matching determination module, which is used to determine whether the network identification comprised in the switch command for the current wireless communication system matches with the network identification for the mobile station, and then send the said switch command to the module for generating the switch instruction if the match is confirmed; 
     module for generating the switch instruction, which is used to generate the switch instruction comprising the network identification for the target wireless communication system according to the said switch command, and send the said switch instruction to the said wireless transceiver module. 
     Beneficial Effects 
     Compared to the prior art, the technical solution in the present invention has the following beneficial effects. 
     1) using different network identifications to distinguish different wireless communication systems and setting the same network identification for the mobile station and the currently associated wireless communication system, which eliminates the problem of the identification conflict in the prior art caused by that the data are sent simultaneously to the mobile station from multiple wireless communication systems within the overlapping region; 
     2) the mobile station modifies its network identification to the network identification for the target wireless communication system according to the switch command sent by the ground sending device, which accomplishes the controlled switching for the mobile station at the overlapping region; 
     3) by comparing the network identification for the mobile station itself with the one comprised in the switch command for the current wireless communication system, the mobile station modifies its network identification only when they are the same, which prevents the ground sending device from controlling the switch of non-switch target mobile station which entering the switching position and reduces the rate of wrong switching. 
    
    
     
       DESCRIPTION OF THE FIGURES 
         FIG. 1  is an illustrative drawing showing the mobile station in the prior art switching between different wireless communication systems; 
         FIG. 2  is an illustrative drawing showing the structure of the switch command involved in one embodiment of the present invention; 
         FIG. 3  is an illustrative drawing showing the structure of equipment according to one embodiment of the present invention; 
         FIG. 4  is an illustrative drawing showing the mobile station according to embodiment 1 of the present invention switching between different wireless communication systems; 
         FIG. 5  is an illustrative drawing showing the mobile station according to embodiment 2 of the present invention switching between different wireless communication systems. 
     
    
    
     DETAILED DESCRIPTION 
     For making the subject, content and advantages of the present invention more clear, a detailed description of the present invention is provided hereinafter with reference to the attached drawings and embodiments. 
     First, the method for controlling the mobile station to switch between different wireless communication systems is described according to the solution of the present invention, with which different wireless communication systems are distinguished by network identifications, and the network identification for the mobile station is modified according to the switch command sent by the ground sending device so as to be associated with the corresponding wireless communication system. A wireless transceiver module is mounted on the mobile station, which is used to be associated with the wireless communication system so as to transmit the data, and an independent receiving module for the switch command is also mounted on the mobile station, which is used to receive the switch command sent by the ground sending device. The ground sending device is mounted at the specified switch position, and when the mobile station passes the switch point, the ground sending device sends switch command to the mobile station which comprises both of the network identifications for the wireless communication system before and after the switch. The mobile station modifies its network identification when receiving the right switch command, and then switches to the target wireless communication system. 
     The said method comprises the following steps. 
     1) setting different network identifications for multiple wireless communication systems, the mobile station is associated with the corresponding wireless communication system so as to send/receive data only when its network identification is the same as that for the wireless communication system; at the beginning, the network identification for the mobile station is set to be the same as that for the wireless communication system desired to be associated with, and then the mobile station is associated with this wireless communication system by which the data is sent/received; 
     2) mounting an independent receiving module for switch command on the mobile station to receive the switch command sent by the ground sending device; 
     3) mounting the ground sending device at the specified position; 
     The sequence among step 1), step 2) and step 3) can be subject to any change; furthermore, a wireless transceiver module is first arranged at the mobile station for associating with the wireless communication system to receive/send the business data, and for setting the network identification for the mobile station itself according to the switch instruction from the control module within the mobile station simultaneously; the function of the said control module is to generate switch instruction according to the switch command received by the said independent receiving module for switch command and to send the switch instruction to the said wireless transceiver module; 
     4) the ground sending device sends the switch command when the mobile station passes the specified switching position, the switch command comprising the network identification for the currently associated wireless communication system and the network identification for the switch target wireless communication system, as shown in  FIG. 2 ; 
     5) after receiving the switch command sent by the ground sending device, the mobile station examines the content of the information, and modifies its network identification to the network identification for the switch target wireless communication system only when the network identification for the mobile station is the same as that comprised in the switch command for the current wireless communication system, and cuts off the link with the original wireless communication system and establishes the link with the target wireless communication system so as to send/receive data; the mobile station terminates the subsequent switching operation when the network identification for the mobile station is different from that for the current wireless communication system, and continues to communicate with the currently associated wireless communication system. 
     An equipment for the aforesaid method of controlling the mobile station to switch between different wireless communication systems is described in detail as follows, as shown in  FIG. 3 , the equipment comprising: 
     wireless transceiver module, which is used to be associated with the wireless communication system, to receive the business data sent by the ground sending device via the wireless communication system, to send the business data to the control module, to send the business data sent by the control module to the wireless communication system simultaneously; it is also used to receive the switch instruction from the control module and set the network identification for the mobile station itself according to the switch instruction; 
     independent receiving module for switch command, which is used to receive the switch command sent by the ground sending device and transmit the switch command to the control module; 
     control module, which is used to receive the business data transmitted by the wireless transceiver module and send the business data to the wireless transceiver module; it is also used to receive the switch command transmitted by the independent receiving module for switch command and send the switch instruction to the said wireless transceiver module according to the said switch command. 
     Wherein, the said control module comprises: 
     matching determination module, which is used to determine whether the network identification comprised in the switch command for the current wireless communication system matches with the network identification for the mobile station, and then send the said switch command to the module for generating the switch instruction if the match is confirmed; 
     module for generating the switch instruction, which is used to generate the switch instruction comprising the network identification for the target wireless communication system according to the said switch command and send the said switch instruction to the wireless transceiver module. 
     Example 1 
     As shown in  FIG. 4 , there are three different wireless communication systems, wireless communication system  1 , wireless communication system  2  and wireless communication system  3 ; terminal equipment M is connected with wireless communication system  1  by means of backbone network  1 , terminal equipment N is connected with wireless communication system  2  by means of backbone network  2 , terminal equipment P is connected with wireless communication system  3  by means of backbone network  3 , backbone networks  1 ,  2  and  3  are either inter-linked with each other or independent of each other, terminal equipment K is connected with the mobile station. There are overlapping regions among wireless communication system  1 , wireless communication system  2  and wireless communication system  3 ; now the mobile station is desired to switch from wireless communication system  1  to wireless communication system  2  at point A within the overlapping region of the wireless communication system  1  and the wireless communication system  2 ; the mobile station is also desired to switch from wireless communication system  2  to wireless communication system  3  at point B within the overlapping region of the wireless communication system  2  and the wireless communication system  3 . 
     Firstly, the aforesaid wireless communication systems are distinguished by different network identifications; the network identification for wireless communication system  1  is “CBTC_ 1 ”, the network identification for wireless communication system  2  is “CBTC_ 2 ”, the network identification for wireless communication system  3  is “CBTC_ 3 ”; only when the network identification for the wireless transceiver module of the mobile station is the same as that for the wireless communication system, the link between the wireless transceiver module of the mobile station and the wireless communication system will be established so as to send/receive the data. 
     In the beginning, the wireless transceiver module of the mobile station is within the range covered by wireless communication system  1 , with its network identification set as “CBTC_ 1 ”. The wireless transceiver module of the mobile station is associated with wireless communication system  1 , the link between terminal equipment K and terminal equipment M is established via the mobile station, wireless communication system  1  and backbone network  1 , before sending/receiving data. 
     The ground sending device is mounted at the specified position A and B; 
     The ground sending device sends the switch command to the independent receiving module for switch command of the mobile station when the mobile station passes point A; the said switch command comprising network identification “CBTC_ 1 ” for the current wireless communication system and network identification “CBTC_ 2 ” for the target switching wireless communication system. 
     After receiving the switch command, the independent receiving module for switch command of the mobile station sends this switch command to the matching determination module within the control module, the matching determination module determines whether the network identification for the current wireless communication system comprised in this switch command is the same as its network identification or not, when the network identification comprised in this switch command for the current wireless communication system is “CBTC_ 1 ”, i.e. the same as its network identification, the matching determination module sends this switch command to the module for generating the switch instruction; and then the module for generating the switch instruction orders the wireless transceiver module to modify its own network identification to the network identification “CBTC_ 2 ” for the target wireless communication system; the mobile station will terminate the subsequent operation when the network identification comprised in the switch command for the current wireless communication system is different from its network identification and continue to communicate with the currently associated wireless communication system. 
     After the wireless transceiver module of the mobile station modifies its network identification to “CBTC_ 2 ”, it cuts off the link with wireless communication system  1  and establishes the link with wireless communication system  2 . 
     The ground sending device sends the switch command to the independent receiving module for switch command of the mobile station when the mobile station passes point B; the said switch command comprising network identification “CBTC_ 2 ” for the current wireless communication system and network identification “CBTC_ 3 ” for the target switching wireless communication system; 
     After receiving the switch command, the independent receiving module for switch command of the mobile station sends this switch command to the matching determination module within the control module, the matching determination module would determine whether the network identification for the current wireless communication system comprised in this switch command is the same as its network identification, if the network identification comprised in this switch command for the current wireless communication system is “CBTC_ 2 ”, i.e. the same as its network identification, the matching determination module sends this switch command to the module for generating the switch instruction; and then the module for generating the switch instruction orders the wireless transceiver module to modify its own network identification to the network identification “CBTC_ 3 ” for the target wireless communication system; the mobile station would terminate the subsequent operation when the network identification comprised in the switch command for the current wireless communication system is different from its network identification, and continue to communicate with the currently associated wireless communication system. 
     After the wireless transceiver module of the mobile station modifies its network identification to “CBTC_ 3 ”, the link with wireless communication system  2  is cut off, while the link with wireless communication system  3  is established. 
     Thus the mobile station accomplishes all desired switch operation. 
     Example 2 
     As shown in  FIG. 5 , there are three different wireless communication systems, wireless communication system  1 , wireless communication system  2  and wireless communication system  3 ; the regions covered by wireless communication systems  1 ,  2 ,  3  are entirely overlapped. In the beginning, the mobile station is associated with wireless communication system  1 , now the mobile station is desired to switch to wireless communication system  2  at point A, to wireless communication system  3  at point B, and to wireless communication system  1  at point C. 
     First, three wireless communication systems said above are distinguished by different network identifications; the network identification for wireless communication system  1  is “DCS_ 1 ”, the network identification for wireless communication system  2  is “DCS_ 2 ”, the network identification for wireless communication system  3  is “DCS_ 3 ”; only when the network identification for the wireless transceiver module of the mobile station is the same as that for the wireless communication system, the wireless transceiver module of the mobile station establishes the link with the wireless communication system so as to send/receive data. 
     In the beginning, the wireless transceiver module of the mobile station sets its network identification as “DSC_ 1 ”, it is associated with wireless communication system  1  so as to send/receive data. 
     Ground sending devices are mounted at specified positions A, B and C; 
     The ground sending device sends the switch command to the independent receiving module for switch command of the mobile station when the mobile station passes point A; the said switch command comprising network identification “DCS_ 1 ” for the current wireless communication system and network identification “DCS_ 2 ” for the target switch wireless communication system. 
     After receiving the switch command, the independent receiving module for switch command of the mobile station sends this switch command to the matching determination module within the control module, the matching determination module would determine whether the network identification for the current wireless communication system comprised in this switch command is the same as its network identification, if the network identification comprised in this switch command for the current wireless communication system is “DCS_ 1 ”, i.e. the same as its network identification, the matching determination module would send this switch command to the module for generating the switch instruction; and then the module for generating the switch instruction orders the wireless transceiver module to modify its own network identification to the network identification “DCS_ 2 ” for the target wireless communication system; the mobile station would terminate the subsequent operation when the network identification comprised in the switch command for the current wireless communication system is different from its network identification and continue to communicate with the currently associated wireless communication system. 
     After the wireless transceiver module of the mobile station modifies its network identification to “DCS_ 2 ”, it cuts off the link with wireless communication system  1  and establishes the link with wireless communication system  2 . 
     The ground sending device sends the switch command to the independent receiving module for switch command of the mobile station when the mobile station passes point B; the said switch command comprising network identification “DCS_ 2 ” for the current wireless communication system and network identification “DCS_ 3 ” for the target switching wireless communication system. 
     After receiving the switch command, the independent receiving module for switch command of the mobile station sends this switch command to the matching determination module within the control module, the matching determination module would determine whether the network identification for the current wireless communication system comprised in this switch command is the same as its network identification, if the network identification comprised in this switch command for the current wireless communication system is “DCS_ 2 ”, i.e. the same as its network identification, the matching determination module would send this switch command to the module for generating the switch instruction; and then the module for generating the switch instruction orders the wireless transceiver module to modify its own network identification to the network identification “DCS_ 3 ” for the target wireless communication system; the mobile station would terminate the subsequent operation when the network identification comprised in the switch command for the current wireless communication system is different from its network identification, and continue to communicate with the currently associated wireless communication system. 
     After the wireless transceiver module of the mobile station modifies its network identification to “DCS_ 3 ”, it cuts off the link with wireless communication system  2  and establishes the link with wireless communication system  3 . 
     The ground sending device sends the switch command to the independent receiving module for switch command of the mobile station when the mobile station passes point C; the said switch command comprising network identification “DCS_ 3 ” for the current wireless communication system and network identification “DCS_ 1 ” for the target switch wireless communication system. 
     After receiving the switch command, the independent receiving module for switch command of the mobile station sends this switch command to the matching determination module within the control module, the matching determination module would determine whether the network identification for the current wireless communication system comprised in this switch command is the same as its own network identification, if the network identification comprised in this switch command for the current wireless communication system is “DCS_ 3 ”, i.e. the same as its network identification, the matching determination module would send this switch command to the module for generating the switch instruction; and then the module for generating the switch instruction orders the wireless transceiver module to modify its own network identification to the network identification “DCS_ 1 ” for the target wireless communication system; the mobile station would terminate the subsequent operation when the network identification comprised in the switch command for the current wireless communication system is different from its network identification, and continue to communicate with the currently associated wireless communication system. 
     After the wireless transceiver module of the mobile station modifies its network identification to “DCS_ 1 ”, it cuts off the link with wireless communication system  3  and establishes the link with wireless communication system  1 ; 
     Thus the mobile station accomplishes all desired switch operation. 
     It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention, such modifications and arrangements are also understood to be within the scope of the present invention. 
     INDUSTRIAL APPLICABILITY 
     The present invention eliminates the problem of identification conflict caused by that the data are sent simultaneously by multiple wireless communication systems at the overlapping region in the prior art, realizes the controlled switch for the mobile station at the overlapping region, and prevents the ground sending device controlling the switch of non-switch target mobile station entering the switching position and reduces the rate of wrong switching.