Wireless communication system, its base station and mobile station, communication synchronization management method and timer control program therefor

Abstract

A wireless communication system is provided for reducing the probability that latency before data transmission increases when a mobile station that is actually in sync is judged to be out of sync. A base station causes the timing calculation part to calculate the timing advance (TA) of a transmit timing from the mth mobile station; causes the timer adaptive control part to obtain the traveling speed or the time variation in TA of the mth mobile station and, adaptively determines and outputs as the timer update information the length of the mth first timer within an M number in total of synchronization timers and the length of the second timer of the mth mobile station and update the length of the mth first timer; and transmits from the downlink transmission part a downlink signal which contains timer update information.

What is claimed is: 
     
       1. A base station of a wireless communication system which performs communication between a mobile station and the base station, the base station comprising:
 a timer unit which sets a period for judging whether an uplink signal from the mobile station is synchronized; and   a timer control unit which determines the set period for each of mobile stations and notifies the set period to each of the mobile stations.   
     
     
       2. The base station of  claim 1 , wherein the base station notifies said set period via a message which is related to a RRC connection. 
     
     
       3. A mobile station of a wireless communication system which performs communication between the mobile station and a base station, the mobile station comprising:
 a unit which judges whether an uplink signal to the base station is synchronized based on a set period which is determined for each of a plurality of mobile stations and notified to each of the mobile stations.   
     
     
       4. The mobile station of  claim 3 , wherein the mobile station received the set period via a message which is related to a RRC connection. 
     
     
       5. A method executed by at least one processor of controlling a base station of a wireless communication system which perfumes communication between a plurality of mobile stations and the base station, the method comprising:
 setting a period for judging whether an uplink signal from one of the mobile stations is synchronized; and   determining the set period for each of the mobile stations and notifies the set period to each of the mobile stations.   
     
     
       6. A method executed by at least one processor of controlling a mobile station of a wireless communication system. which performs communication between the mobile station and a base station, the method comprising:
 judging whether an uplink signal to the base station is synchronized based on a set period which is determined for each of a plurality of mobile stations and notified to each of the mobile stations.   
     
     
       7. A wireless communication system which performs communication between a mobile station and a base station, wherein the base station comprises:
 a timer unit which sets a period for judging whether an uplink signal from the mobile station is synchronized,   a timer control unit which determines the set period for each of a plurality of mobile stations and notifies the set period to each of the mobile stations; and   wherein the mobile station comprises:
 a unit which judges whether an uplink signal to the base station is synchronized based on a set period which is determined for each of the mobile stations and notified to each of the mobile stations. 
   
     
     
       8. A method executed by a mobile station among a plurality of mobile stations in a cell managed by a base station, the method comprising:
 receiving a cell specific timer value of a timer, wherein the cell specific timer value of the timer is common to all of the plurality of mobile stations in the cell;   receiving a mobile station dedicated timer value of the timer after receiving the cell specific timer value, wherein the mobile station dedicated timer value of the timer is transmitted by the base station to the mobile station dedicatedly;   receiving a timing advance to control uplink synchronization; and   determining if one or more uplink signals is synchronized by using the mobile station dedicated timer value of the timer after receiving the mobile station dedicated timer value of the timer.    
     
     
       9. The method of claim 8, wherein the method further comprises:
 receiving the cell specific timer value of the timer included in system information; and   receiving the mobile station dedicated timer value of the timer included in a message which is related to a RRC connection.    
     
     
       10. A mobile station among a plurality of mobile stations in a cell managed by a base station, the mobile station comprising:
 a receiver configured to:
 receive a cell specific timer value of a timer before receiving a mobile station dedicated timer value of the timer, wherein the cell specific timer value of the timer is common to all of the plurality of mobile stations in the cell; 
 receive the mobile station dedicated timer value of the timer, wherein the mobile station dedicated timer value of the timer is transmitted by the base station to the mobile station dedicatedly; and 
 receive a timing advance to control uplink synchronization; and 
   a processor configured to determine if one or more uplink signals is synchronized by using the mobile station dedicated timer value of the timer after the receiver receives the mobile station dedicated timer value of the timer.    
     
     
       11. The mobile station of claim 10, wherein the receiver is configured to receive the cell specific timer value of the timer included in system information and to receive the mobile station dedicated timer value of the timer included in a message which is related to a RRC connection.  
     
     
       12. A mobile station among a plurality of mobile stations in a cell managed by a base station, the mobile station comprising:
 a receiver configured to:
 receive a cell specific timer value of a timer, wherein the cell specific timer value of the timer is common to all of the plurality of mobile stations in the cell; 
 receive a mobile station dedicated timer value of the timer after receiving the cell specific timer value, wherein the mobile station dedicated timer value of the timer is transmitted by the base station to the mobile station dedicatedly; and 
 receive a timing advance to control uplink synchronization; and 
   a processor configured to determine if one or more uplink signals is synchronized by using the mobile station dedicated timer value after the receiver receives the mobile station dedicated timer value of the timer.    
     
     
       13. The mobile station of claim 12, wherein the receiver is configured to receive the cell specific timer value included in system information.  
     
     
       14. The mobile station of claim 13, wherein the receiver is configured to receive the cell specific timer value included in system information broadcast to the plurality of mobile stations.  
     
     
       15. The mobile station of claim 12, wherein the receiver is configured to receive the mobile station dedicated timer value of the timer included in a message which is related to a RRC connection.  
     
     
       16. The method of claim 8, wherein the method further comprises transmitting, to the base station, the one or more uplink signals.  
     
     
       17. The mobile station of claim 10, wherein the mobile station further comprises a transmitter, wherein the transmitter is configured to transmit, to the base station, the one or more uplink signals.  
     
     
       18. The mobile station of claim 12, wherein the mobile station further comprises a transmitter, wherein the transmitter is configured to transmit, to the base station, the one or more uplink signals.  
     
     
       19. The method of claim 8, wherein the method further comprises determining if one or more uplink signals is synchronized by using the cell specific timer value of the timer if the mobile station does not receive the mobile station dedicated timer value of the timer.  
     
     
       20. The mobile station of claim 10, wherein the processor is configured to determine if one or more uplink signals is synchronized by using the cell specific timer value of the timer if the receiver does not receive the mobile station dedicated timer value of the timer.  
     
     
       21. The mobile station of claim 12, wherein the processor is configured to determine if one or more uplink signals is synchronized by using the cell specific timer value of the timer if the receiver does not receive the mobile station dedicated timer value of the timer.