An intelligent hybrid spread spectrum MAC protocol for increasing the transmission capacity of wireless ad-hoc networks

Abstract

Unmanaged interference is a threat to reliable communication in ad hoc networks. Currently, ad hoc networks suppress or inhibit interferers around an active receiver to meet a minimum required signal-to-interference-plus-noise ratio threshold. Techniques like carrier sensing, random back-offs, spread spectrum, guard zone based inhibition, etc. are being used for interference management. We have developed a MAC protocol that works on the principle of not inhibiting any interferer near an active receiver. The proposed scheme uses Direct Sequence Spread Spectrum network-wide and intelligent Frequency Hopping within a zone around the receiver. Mathematical model based on stochastic geometry is validated through simulation. It is observed that proposed MAC protocol shows performance improvement over other MACs, in terms of Transmission Capacity normalized by the used spectrum.