Godfrey Tan, John Guttag
IEEE INFOCOM, Miami, FL, March 2005
Wireless local area networks (WLANs) based on the family of 802.11 technologies are becoming ubiquitous. These technologies support multiple data transmission rates. Transmitting at a lower data rate (by using a more resilient modulation scheme) increases the frame transmission time but reduces the bit error rate. In non-cooperative environments such as public hot-spots or WLANs operated by different enterprises that are physically close to each other, individual nodes attempt to maximize their achieved throughput by adjusting the data rate or frame size used, irrespective of the impact of this on overall system performance.
In this paper, we show both analytically using a game theoretic model
and through simulation that the existing 802.11 distributed MAC
protocol, DCF (for Distributed Coordination Function), as well as its
enhanced version, which is being standardized at part of 802.11e, can
lead non-cooperative nodes to undesirable Nash equilibriums, in which
the wireless channel is inefficiently used. We show that by establishing
independence between the allocation of the shared channel resource and
the transmission strategies used by individual nodes, an ideal MAC
protocol can lead rational nodes to arrive at equilibriums in which all
competing nodes achieve higher throughputs than with DCF.
[PDF (180KB)] [PostScript (394KB)]
Bibtex Entry:
@inproceedings{tan2005802.11,
author = "Godfrey Tan and John Guttag",
title = "{The 802.11 MAC Protocol Leads to Inefficient Equilibria}",
booktitle = {IEEE INFOCOM},
year = {2005},
month = {March},
address = {Miami, FL}
}