A Hidden Node Aware Network Allocation Vector Management System for Multi-hop Wireless Ad hoc Networks

Document Type : Research Paper


Department of Electrical Engineering, K. N. Toosi University of Technology


Many performance evaluations for IEEE 802.11
distributed coordination function (DCF) have been previously
reported in the literature. Some of them have clearly indicated
that 802.11 MAC protocol has poor performance in multi-hop
wireless ad hoc networks due to exposed and hidden node
problems. Although RTS/CTS transmission scheme mitigates
these phenomena, it has not been successful in thoroughly
omitting these drawbacks. We argue that when eliminating
hidden node effect with a given protocol is not feasible, one
may sometimes earn more throughput by controlling or even
wisely creating this phenomenon. In this paper we propose a
novel solution to improve the performance of IEEE 802.11
MAC protocol in multi-hop networks through modifying NAV
timer. We may call this method Dynamic NAV (DNAV) since
the NAV timer operation changes dynamically with the change
of environment variables. Simulation results show that our
approach noticeably increases the throughput in multi-hop
wireless ad-hoc networks.