Patent ID: 7574226

Claim:
A mobile communication system comprising: a base station; and a mobile station configured to communicate with said base station, wherein a plurality of state update frames are defined in a time domain in a communication protocol between said base station and said mobile station, said base station can transmit a state update data in each of said plurality of state update frames to instruct which of an active state and a suspended state said mobile station should be set to, and transmits a packet only to said mobile station which has been set to said active state based on said state update data, said base station pre-announces transmission of said packet to said mobile station earlier by a predetermined time period than the transmission of said packet by transmitting a control data containing data necessary to receive said packet, and said mobile station is set to one of said active state and said suspended state in response to said state update data, can receive said control data and said packet when said mobile station has been set to said active state, and cannot receive said control data and said packet when said mobile station has been set to said suspended state.