PAWP: a power aware Web proxy for wireless LAN clients

The relative power consumed in the WLAN interface of a mobile device is rising due to significant improvements in the energy efficiency of the other device components. The unpredictability of the incoming WLAN traffic limit the effectiveness of existing power saving techniques. This paper introduces a power aware Web proxy (PAWP) architecture designed to schedule incoming Web traffic into intervals of high and no communication. This traffic pattern allows WLAN interfaces to switch to a low power state after very short idle intervals. PAWP uses a collection of HTTP-level techniques to compensate any negative impact that traffic scheduling may have. PAWP does not require any client or Web server modifications. In this paper, we describe our initial experiences with a PAWP implementation for 802.11b WLANs. Our experiments show savings of more than 50% in the energy consumed by the WLAN interface. Finally, our experiences give us insights into possible browser improvements when power consumption is taken into account.