A channel-aware adaptive control to the MAC protocol in rate adaptive wireless LANs

LANGUAGE
English
SOURCE
Wireless Communications & Mobile Computing archive Volume 5, Issue 8 (December 2005)
Published Date:2005-12-01
ABSTRACT
Due to the low efficiency of legacy IEEE 802.11 MAC protocol, it has been the main bottleneck of wireless local area networks (WLANs). In this paper, we focus on multi-rate WLANs and propose an adaptive transmission control scheme, which adapts the transmission probability according to the number of active stations, transmission rates, and channel conditions. At first, an analytical model is built in terms of the proposed scheme to explore the throughput of the network. Then, by means of the characteristics of practical system, a heuristic algorithm is developed to approach the maximum throughput on-line. Extensive numerical calculations and simulations based on NS-2 are implemented to evaluate the performance of the proposed algorithm and the impact of inaccurate estimation of parameters. The results show that our algorithm outperforms the existing adaptive algorithms in imperfect channel, and insensitive to inaccurate estimation of parameters.
KEYWORDS
multi-rate WLANs; DCF; rate adaptive transmission control; heuristic algorithm