Sharp Kabushiki Kaisha Corporation

Minoru Kosaka

Katsuyuki Machino

Shigetaka Noguchi

A wireless communication system that includes a base station and one or more terminals carries out wireless data communication by use of a first frequency band. The wireless communication system includes a wireless access system that employs a CSMA/CA and/or TDMA/TDD system as the wireless access system of the wireless communication system and a control signal at the first frequency band is periodically broadcasts from the base station, where the control signal includes a control information configured to manage wireless data transmission by the one or more terminals. In addition to the first frequency band, one or more frequency bands different from the first frequency band for the wireless data transmission by the one or more terminals can be allocate by the base station, where the control signal at the first frequency band indicate the location of the one or more frequency bands which can be used.

Wireless communication system

A wireless communication system broadcasts a control signal at a first frequency band from a base station and allocates additional frequency band(s) for transmitting data by terminal(s). A control signal at the first frequency band indicates the location of the additional frequency band(s) and is not transmitted over the additional frequency band(s). Wireless data transmission is simultaneously performed over the first frequency band and the additional frequency band(s). Each terminal receives the control signal, which is used in time-synchronizing frames between the wireless data transmission at the first frequency band and the wireless data transmission at the additional frequency band(s). The control signal also includes control data for managing wireless data transmission of the terminal(s) at the first frequency band, and is utilized instead of a control signal at the additional frequency band(s).

A wireless communication system broadcasts a control signal at a first frequency band from a base station and allocates additional frequency band(s) for transmitting data via terminal(s). A control signal at the first frequency band indicates the location of the additional frequency band(s) and is not transmitted over the additional frequency band(s). Wireless data transmission is simultaneously performed over the first frequency band and the additional frequency band(s). Each terminal receives the control signal, which is used in time-synchronizing frames between the wireless data transmission at the first frequency band and the wireless data transmission at the additional frequency band(s). The control signal also includes control data for managing wireless data transmission between the base station and the terminal(s) at the first frequency band, and is utilized instead of a control signal at the additional frequency band(s).

In a wireless communication system, a central control unitcomprises 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 unitalso 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 stationor a mobile station. Frames for the base station-mobile station communication and the inter-mobile station direct communication are synchronized by utilizing control informationfor 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.

A second wireless communication system comprises reception means for receiving a control signal transmitted by a first wireless system which defines its own communication-enabled period based on the control signal, and communication control means for determining, based on the control signal, a vacant time region in the communication-enabled period that is not utilized by the first wireless communication system, and allocating the vacant time region as its own communication time region.

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Chiba, Japan

Minoru Kosaka