Cross Layer Multirate Adaptation Using Physical Capture

In this paper, to improve the performance of multihop wireless networks, we explore a cross layer multirate adaptation scheme (we call it CROMA) that uses the phenomenon of physical capture at the physical layer for effectively distinguishing losses due to collisions from those due to channel-error. We first estimate the number of packets dropped due to collisions, at each node by counting the number of packets that are not successfully retrieved by physical capture. Next, using a simple algorithm, we assign this collision loss to neighboring sources of packets that might have generated the colliding packets. Using extensive ns-2 simulations, we show that our multirate adaptation scheme consistently outperforms the existing schemes.