A joint solution for the hidden and exposed terminal problems in CSMA/CA wireless networks

It is well-known that the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)-based wireless networks suffer seriously from the hidden terminal problem and the exposed terminal problem. So far, no satisfactory solutions that can resolve both problems simultaneously have been found. In this paper, we present a joint solution to the two problems. Our approach avoids the drawback of lessening one problem but aggregating the other. It is compatible with the IEEE 802.11 MAC and requires no protocol change. Analysis and simulations show that the proposed scheme can significantly reduce the hidden and exposed terminal problems. Not only it can significantly improve the throughput of the network and the fairness among different flows, it can also provide a much more stable link layer. In simulated scenarios under heavy traffic conditions, compared to the conventional IEEE 802.11 MAC, the new method can achieve up to 1.8 times gain in network throughput for single-hop flows and up to 2.6 times gain for multihop flows. (C) 2012 Elsevier B.V. All rights reserved.