An apparatus and method for an improved sleep mode in a mobile terminal are provided. The apparatus includes a transceiver for communicating with a base station, a modem for modulating and demodulating signals for transmission via the transceiver or received via the transceiver, and a controller for controlling a sleep cycle of the mobile terminal, the sleep cycle including a listening window and a sleep window. The controller controls the sleep cycle based on an Advanced Mobile Station (AMS) timer, a Hybrid Repeat Request (HARQ) Downlink (DL) Retransmission timer, a HARQ DL Gap timer, and a HARQ Uplink (UL) Gap timer.