Abstract

A novel wireless MAC protocol named MACA-BI (MACA By Invitation) is introduced. MACA-BI is a simplified version of the well known MACA (Multiple Access Collision Avoidance) protocol, which is based on the Request to Send/Clear to Send (RTS/CTS) handshake and which has inspired the IEEE 802.11 wireless LAN standard. In MACA-BI, the RTS part of the RTS/CTS handshake is suppressed, leaving only the Clear to Send control message which can be viewed as an "invitation" by the receiver to transmit. This reduction greatly improves efficiency when radio turn-around time is significant with respect to packet transmission time. Yet, it preserves the "data" collision free property of MACA. Simulation results for various multihop topologies show that, when traffic characteristics are stationary or predictable, MACA-BI outperforms several known multiple access protocols, especially when "hidden terminal" conditions are predominant.

Citations