Elimination of exposed terminal problem using signature detection

This paper represents the design of Interference Resistant Multiple Access (IRMA), a novel cross layer protocol that can combat exposed terminals and exploit the concurrent transmissions in wireless networks, both helping in achieving higher throughput compared to the 802.11 standard and other recent protocols. By observing that nodes in current protocols waste transmission opportunities in two different scenarios, IRMA exploits the concurrency in two aspects. IRMA proposes a signature detection method in the physical layer to combat control frames´ collisions, thus exploits the concurrency at the transmitter side. IRMA also designs a new NAV update scheme in the MAC layer to differentiate the interference ranges of different transmission links, thus exploits the concurrency of all non-interfering links. In addition, IRMA is based on the 802.11 standard so that it can be implemented into current devices. Experimental results based on USRP2 demonstrate the feasibility of the signature detection method, and simulations based on NS2 show that IRMA outperforms other protocols significantly.