@INPROCEEDINGS {qun_infocom06,
	author = {Lei Guo and Xiaoning Ding and Haining Wang and Qun
	Li and Songqing Chen and Xiaodong Zhang},
	booktitle = {{IEEE} Infocom 2006},
	PAGES = {},
	TITLE = {Exploiting Idle Communication Power for Improving Wireless Network Performance and Energy Utility}, 
	Address ={Barcelona, Spain},
	Month={April},
	YEAR = {2006}
	}


Abstract:

As a family of wireless local area network (WLAN)
protocols between physical layer and higher-layer protocols,
IEEE 802.11 has to accommodate the features and requirements
of both ends. However, current practice has addressed the
problems separately and is far from being satisfactory. On one
end, due to varying channel conditions, WLANs have to provide
multiple data channel rates to support various signal qualities.
A low channel rate station not only suffers low throughput, but
also significantly degrades the throughput of other stations. On
the other end, TCP is not energy efficient running on 802.11.
In a TCP session, a wireless network interface (WNI) has to
stay awake to generate timely acknowledgments, and hence, the
energy is wasted by channel listening during idle awake time.
In this paper, considering the needs of both ends, we utilize the
idle communication power of the WNI to improve the throughput
and energy efficiency of stations in WLANs with multiple channel
rates. We characterize the energy efficiency as energy per bit,
instead of energy per second. Based on modeling and analysis,
we propose a data forwarding mechanism and an energy-aware
channel allocation mechanism. In such a system, a high channel
rate station relays data frames between its neighboring stations
with low channel rates and the Access Point, improving their
throughput and energy efficiency. Different from traditional
relaying approaches, our scheme compensates for the energy
consumption for data forwarding. The forwarding station obtains
additional channel access time from its beneficiaries, leading to
the increase of its own throughput without compromising its
energy efficiency. We implement a prototype of our proposed
system and evaluate it through extensive experiments. Our results
show significant performance improvements for both low and
high channel rate stations.