A Spatial Backoff Algorithm UsingtheJoint Control of Carrier SenseThreshold andTransmission Rate

Traditional mediumaccess control (MAC) protocols utilize temporal mechanisms suchasaccess probability orbackoff interval adaptation forcontention resolution. Temporal contention resolution aimstosepa- ratetransmissions fromdifferent nodesintimetoachieve successful transmissions. We explore analternative ap- proach forwireless networks-named "spatial backoff"- thatadapts the"space" occupied bythetransmissions. By adapting thespaceoccupied bytransmissions, the setof"locally" competing nodes, andthus, thechannel contention level, canbeadjusted toreachasuitable level. Therearedifferent waystorealize spatial backoff. Inthis paper, we propose a dynamic spatial backoff algorithm usingthejoint control ofcarrier sensethreshold and transmission rate. Ourresults suggest thatspatial backoff ispromising toimprove thechannel utilization.