WSN05-1: A Dual Busy-Tone MAC Scheme Supporting Voice/Data Traffic in Wireless Ad Hoc Networks

In wireless ad hoc networks, in addition to the well-known hidden terminal and exposed terminal problems, the location-dependent contention may cause serious unfairness and priority reversal problems. These problems can severely degrade network performance. In this paper, a new busy- tone based medium access control (MAC) scheme supporting voice/data traffic is proposed to address these problems. Via two separated narrow band busy-tone channels with different carrier sense ranges, the proposed scheme completely resolves the hidden terminal and exposed terminal problems. Furthermore, by extending busy-tones in the transmitter busy-tone channel, the proposed scheme ensures guaranteed priority access for delay-sensitive voice traffic independent of the user locations. The long- term and short-term fairness performance for data traffic in a multi-hop environment is also greatly improved as compared with the popular IEEE 802.11e MAC scheme.