Performance enhancement of DQMAN-based wireless ad hoc networks in multi-hop scenarios

Two mechanisms to improve the performance of wireless ad hoc networks in multi-hop scenarios wherein the Distributed Queuing MAC protocol for Mobile Ad Hoc Networks (DQMAN) is executed are proposed and evaluated in this paper. DQMAN organizes the network into dynamic clusters forming spontaneous master-slave architectures to manage the radio resources. In multihop settings its performance is hampered by intercluster interference (interference caused between adjacent clusters) and the presence of isolated nodes that cannot get associated to any cluster. The Three Hop Master minislot (3HMS) and the Active Listening (AL) mechanisms are presented in this paper to cope with these problems. It is worth noting that these mechanisms could be indeed applied to any centralized network or any clustered ad hoc network. Computer simulations show an overall improvement of the system performance in terms of throughput and average packet transmission delay in comparison to both the basic definition of DQMAN and the legacy IEEE 802.11. MAC protocol in ad hoc mode (DCF) when the enhanced mechanisms are used.