Patent ID: 8412195

Claim:
A method for simultaneously communicating data via a first base station supporting a first radio access technology (RAT) and a second base station supporting a second RAT in a radio access system supporting multiple RAT (multi-RAT), the method comprising: allowing the first base station to perform a registration procedure with the second base station; and allowing the first base station to transmit control information required for accessing the second base station to a terminal supporting multi-RAT (multi-RAT terminal), wherein the control information comprises beacon frame transmission timing information for the second base station, and the beacon frame transmission timing is maintained in transmission timing of a downlink frame or downlink sub-frame of the first base station with relative timing offset interval, wherein the relative timing offset interval indicates an interval between a downlink frame or downlink sub-frame of the first RAT and a beacon frame of the second RAT to synchronize the downlink frame or downlink sub-frame of the first RAT and the beacon frame of the second RAT, wherein the simultaneous communication of data via the first base station and the second base station occurs under control of a cellular network without switching mechanism in the multi-RAT terminal, and wherein the first RAT is a radio access technology supporting a cellular system, and the second RAT is a radio access technology supporting a wireless local area network (WLAN).