Alleviating Self-Interference in MANETs

Alex Varshavsky, Eyal de Lara

th International IEEE Workshop on Wireless Local Networks (WLN), Tampa, FL, November 2004



The interference range in multi-hop ad hoc networks (MANETs) is typically twice as large as the transmission range. This phenomena causes packets of a multi-hop flow to interference with each other as they are relayed over the multi-hop route. This interference, an instance of the notorious hidden terminal problem, is caused by simultaneous transmissions by down-stream nodes unaware of ongoing transmissions by up-stream nodes. DMAC is a novel MAC protocol that alleviates the hidden terminal problem by deferring further transmissions until the previously transmitted packets travel far enough to avoid interference with the newly transmitted packets. For simple chain topologies, DMAC improves the throughput of CBR and TCP flows by up to 100% and 60%, respectively. For random mobile topologies with up to 40 simultaneous flows, DMAC improves the throughput of TCP flows by up to 30%.