1. A radio terminal which intermittently receives beacons transmitted from a radio base station at regular intervals and beacons each having a delivery traffic indication map transmitted from the radio base station at intervals of certain beacon intervals, in which, having recognized that its packets are buffered in the radio base station by extracting information elements included in a received beacon, the radio terminal sends the radio base station a control packet to request delivery of the packets, thereby receiving the packets buffered in the radio base station, including: a timer value changing section for dynamically changing one or more timer values according to the operation mode of each communication application running on the radio terminal.