Differentiate Backoff Mechanisms for Transmission Directions in IEEE 802.11 Multihop WLANs

Distributed Coordinate Functions (DCF) is the mandatory medium access method for IEEE 802.11 Wireless Local Area Networks (WLANs), which is designed for infrastructure WLANs where all end users connect with Access Point (AP) with single-hop links. DCF doubles its Contention Window (CW) before each retransmission. However, in multi-hops WLANs, a node may encounter different kinds of transmission failures from different transmission directions. In this paper, we will point out that, in some situations doubling CW before retransmitting makes DCF exploit the medium inefficiently. We also propose a method to resolve this problem by employing different backoff mechanisms for different transmission directions. NS-2 simulations demonstrate a significant throughput improvement of our enhanced MAC over the native MAC.

[1]  Pramod K. Varshney,et al.  Tuning the carrier sensing range of IEEE 802.11 MAC , 2004, IEEE Global Telecommunications Conference, 2004. GLOBECOM '04..

[2]  Biplab Sikdar,et al.  Improving spatial reuse of IEEE 802.11 based ad hoc networks , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).

[3]  Yiwei Thomas Hou,et al.  Exploiting Location Information for Concurrent Transmissions in Multihop Wireless Networks , 2009, IEEE Transactions on Vehicular Technology.

[4]  Yiming Wang,et al.  Performance investigation of IEEE 802.11 MAC in multihop wireless networks , 2005, MSWiM '05.

[5]  Charles E. Perkins,et al.  Ad hoc On-Demand Distance Vector (AODV) Routing , 2001, RFC.

[6]  David Starobinski,et al.  Performance of wireless networks with hidden nodes: a queuing-theoretic analysis , 2005, Comput. Commun..

[7]  Frank H. P. Fitzek,et al.  Design and performance of an enhanced IEEE 802.11 MAC protocol for multihop coverage extension , 2003, IEEE Wireless Communications.

[8]  Shugong Xu,et al.  Does the IEEE 802.11 MAC protocol work well in multihop wireless ad hoc networks? , 2001, IEEE Commun. Mag..

[9]  Alexander L. Stolyar,et al.  Joint Scheduling and Congestion Control in Mobile Ad-Hoc Networks , 2008, IEEE INFOCOM 2008 - The 27th Conference on Computer Communications.

[10]  G. Mazzini,et al.  Design and Performance of an Enhanced IEEE 802 . 11 MAC Protocol for Ad Hoc Networks , 2003 .

[11]  Jing Zhu,et al.  Leveraging spatial reuse in 802.11 mesh networks with enhanced physical carrier sensing , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).