Micro Power Management of Active 802.11 Interfaces

Authors: J. Liu, L. Zhong

Submitted to MobiSys 2008

Abstract

Wireless interfaces are major power consumers on mobile systems. Considerable research has improved the energy efficiency of elongated idle periods or created more elongated idle periods in wireless interfaces, often requiring cooperation from applications or the network infrastructure. With increasing wireless mobile data, it has become critical to improve the energy efficiency of active wireless interfaces. In this work, we present micro power management (μPM), a solution inspired by the mismatch between the high performance of state-of-the art 802.11 interfaces and the modest data rate requirements by many popular network applications. μPM enables an 802.11 interface to enter unreachable power-saving modes even between MAC frames, without noticeable impact on the traffic flow. To control data loss, μPM leverages the retransmission mechanism in 802.11 and controls frame delay to adapt to demanded network throughput with minimal cooperation from the access point. Based on a theoretical framework, we employ simulation to systematically investigate an effective and efficient implementation of μPM. We have built a prototype u Pm on an open-access wireless hardware platform. Measurements show that more than 30% power reduction for the wireless transceiver can be achieved with μPM for various applications without perceptible quality degradation.

        {Liu:2008,
	Author = {J. Liu, L. Zhong},
	Journal = {MobiSys'2008,
	Title = {Micro Power Management of Active 802.11 Interfaces},
	Year = {2008}}