Patent attributes
A mobile communication system includes a plurality of RAT (Radio Access Technology) and can eliminate the need of a control channel for reporting RAT information. An LTE relay station has a cover area identical to a cover area owned by a WLAN host station and relays/transmits the signal received from an LTE base station to a mobile station in the cover area of the LTE relay station. The LTE relay station adds to the signal received from the LTE base station, one of the offsets: a frequency offset, a time offset, and a power offset as information indicating that the mobile station which receives a relay signal from the local station is located in the cover area of WLAN and transmits the signal after offset addition to the mobile station located in the cover area of the LTE relay station (i.e., the cover area of WLAN).