Patent ID: 7953458

Claim:
A method for controlling a sleep mode operation by a mobile station in a communication system, the method comprising: after entering a sleep mode, transitioning to an awake state in a listening interval; when there is data to transmit to or receive from a base station in the awake state, causing a neutral interval following the listening interval to transition to the awake state, and transmitting or receiving the data; and when there is no data to transmit to or receive from the base station in the awake state, transitioning to the sleep state in the neutral interval, wherein the neutral interval is an interval where transition to the awake state and sleep state in the sleep mode is available according to the data transmission or data reception of the mobile station operating in the sleep mode, and wherein a length of the listening interval and a length of a sleep interval following the neutral interval in the sleep mode are determined through an exchange of a SLP-REQ message and a SLP-RSP message between the mobile station and the base station, and are changed according to a state transition of the neutral interval.