In this paper we present an previous term adaptive application-driven power managementnext term (AADPM) strategy with online idle period length distribution learning capability for the IEEE 802.11b previous termWLAN.next term We discuss its design and evaluate the performance in comparison with other previous termpower managementnext term strategies using the network simulator NS2. We simulated both the single user and multiple user scenarios. Experimental results have shown that, compared with other previous termpower managementnext term methods examined in this paper, AADPM achieved the highest energy saving in all cases and it demonstrated strong adaptability to network congestion.