US Patent 7486928 Methods and apparatus for wireless communications

The present invention provides a system for wireless data communications that allows, in P-MP wireless data communications, equally giving communications opportunities to mobile stations that directly communicate with a wireless base station and mobile stations that indirectly communicate therewith via a relay station and a communications method thereof. In comparison with the OFDM frame configuration prescribed in IEEE802.16, an OFDM frame configuration is characterized in that, in an uplink subframe, a ranging period and BW (bandwidth) request periods for a relay station are provided, and furthermore, a remaining message number notice period for which each relay station notifies the wireless base station of the number of remaining messages is provided. These periods are not of a contention base but bandwidths dedicated to the relay station.