Janus: A Novel MAC Protocol for Full Duplex Radio

This paper presents Janus, a novel MAC protocol for full–duplex wireless networks. Unlike other full-duplex MACs, Janus allows partially interfering nodes to cooperate by finding the appropriate transmission rates based on interference levels, making better use of the channel. Computing the optimal schedule and transmission rates is NP-Complete, so Janus uses a cheaper heuristic approach. Janus also ensures that channel access time is shared fairly between all nodes. Janus has lower per-packet overhead compared to CSMA/CA because it eliminates random back-off and lets nodes transmit multiple packets with a single set of control packets. We show that for a setup with one access point and three nodes, Janus achieves 2.5X the throughput of half–duplex system based on CSMA/CA.