An Adaptive Backoff Algorithm for IEEE 802.11 DCF with Cross-Layer Optimization

Based on the analysis of TCP performance of over the two ways of IEEE 802.11 DCF (RTS/CTS and CSMA/CA), TCP flows becomes unstable when WLAN is in high load. In this paper, we propose a novel backoff algorithm for IEEE 802.11 DCF named as ACWB (adaptive contention window backoff) with cross-layer optimization. Its basic idea is to dynamically adjust the size of the contention window by the estimation of the number of active nodes in the network according to information interaction between MAC-layer and transport-layer to avoid the hidden node problem in WLAN and alleviate the bad influence of MAC access mechanism on TCP congestion control. Simulation results show that ACWB algorithm can improve the TCP throughput and stability effectively.

[1]  Milosh V. Ivanovich,et al.  On TCP performance enhancing proxies in a wireless environment , 2008, IEEE Communications Magazine.

[2]  Hyoung-Nam Kim,et al.  Estimation of Number of Tags in ALOHA-based RFID Systems , 2007 .

[3]  Van Jacobson,et al.  Congestion avoidance and control , 1988, SIGCOMM '88.

[4]  T. V. Lakshman,et al.  Design considerations for supporting TCP with per-flow queueing , 1998, Proceedings. IEEE INFOCOM '98, the Conference on Computer Communications. Seventeenth Annual Joint Conference of the IEEE Computer and Communications Societies. Gateway to the 21st Century (Cat. No.98.

[5]  Xiaodong Wang,et al.  TCP performance over wireless MIMO channels with ARQ and packet combining , 2006, IEEE Transactions on Mobile Computing.

[6]  Kee Chaing Chua,et al.  A Capacity Analysis for the IEEE 802.11 MAC Protocol , 2001, Wirel. Networks.

[7]  Kai Xu,et al.  TCP-Jersey for wireless IP communications , 2004, IEEE Journal on Selected Areas in Communications.

[8]  Panganamala Ramana Kumar,et al.  A cautionary perspective on cross-layer design , 2005, IEEE Wireless Communications.

[9]  Marco Conti,et al.  IEEE 802.11 protocol: design and performance evaluation of an adaptive backoff mechanism , 2000, IEEE Journal on Selected Areas in Communications.

[10]  Baowen Xu,et al.  TCP Performance Dynamics and Link-Layer Adaptation Based Optimization Methods for Wireless Networks , 2007, IEEE Transactions on Wireless Communications.