Radio communication system

Abstract

In a wireless communication system, a central control unit 31 comprises a synchronizing means for synchronizing a frame for an base station-mobile station communication with that for an inter-mobile station direct communication based on control information used for the base station-mobile station communication, when a second frequency is used for the inter-mobile station direct communication which is different from a first frequency used for the base station-mobile station communication. The central control unit 31 also comprises an allocation means for allocating a band and a frequency for the inter-mobile station direct communication in accordance with an allocation request from a base station 30 or a mobile station 40 . Frames for the base station-mobile station communication and the inter-mobile station direct communication are synchronized by utilizing control information 55 for the base station-mobile station communication instead of the conventional control information provided by the mobile station. The system allows a base station-mobile station communication to take place even when an inter-mobile station direct communication is conducted at a frequency other than that of the base station. As the base station controls the inter-mobile station direct communication, the burden on the mobile stations can be reduced, and a single base station can use multiple frequencies simultaneously.

1 . A wireless communication system comprised of a base station and mobile stations wirelessly connected to the base station, wherein the mobile stations can communicate with one another without the intervention of the base station, the system further comprising a synchronizing means, wherein 
 when a second frequency is used for inter-mobile station direct communication that is different from a first frequency used for a base station-mobile station communication, the synchronizing means synchronizes a frame in base station-mobile station communication with that in inter-mobile station direct communication based on control information used in base station-mobile station communication.    
     
     
         2 . A mobile station wirelessly connected to a base station and capable of base station-mobile station communication at a first frequency and inter-mobile station direct communication at a second frequency that is different from the first frequency without the intervention of the base station, the mobile station comprising a synchronizing means for synchronizing a frame in base station-mobile station communication with that in inter-mobile station direct communication based on control information used in base station-mobile station communication.  
     
     
         3 . A base station in a wireless communication system comprised of the base station and mobile stations wirelessly connected to the base station, the base station comprising an allocation means for allocating a second frequency for inter-mobile station direct communication, which is different from a first frequency used for base station-mobile station communication in response to a request from a mobile station.  
     
     
         4 . A base station in a wireless communication system comprised of the base station and mobile stations wirelessly connected to the base station, the system capable of conducting base station-mobile station communication at a first frequency and inter-mobile station direct communication at a second frequency different from the first frequency without the intervention of the base station, the base station comprising: 
 an allocation means for allocating bands in a frame for inter-mobile station direct communication based on a request from a mobile station.    
     
     
         5 . The base station according to  claim 3 , further comprising a carrying means for performing carrier sensing at a plurality of available frequencies and carrying available frequencies other than the frequency used by the base station.