Opportunistic Relays in 802.11 Networks

We propose a new lightweight mechanism called Forwarding By Retransmission, that allows 802.11 stations to opportunistically relay overheard frames toward a destination. When a destination does not receive a frame, any other receiver that has better radio conditions than the source of the frame could participate in the retransmission process along with the source. This reduces the number of retransmissions made by stations with poor connectivity. We show by NS-2 simulations that our mechanism allows to fairly share the bandwidth among stations, even for those with poor radio quality and high packet error rates. Our solution comes with only a few modifications to the frame structure and a change in the acknowledgement semantic.