A new binary conflict resolution-based MAC protocol for impulse-based UWB ad hoc networks

Ultra wide band (UWB) technology offers a promising high capacity solution for short-range wireless ad hoc networks, as in home networks or in wearable ad hoc networks. In this paper, we propose a novel multi-band MAC protocol for use in small ad hoc networks that deploy an underlying UWB based physical layer. In our approach, we divide the available UWB bandwidth into multiple simultaneously usable bands. In the absence of a sophisticated equalizer, the size of a slot for transmitting a UWB pulse is typically dictated by the delay spread of the channel. Therefore, using a wider frequency band to shorten the transmission time for each pulse does not increase the data rate in proportion to the available bandwidth. A multi-band approach that uses a plurality of bands that adhere to FCC specifications, with slightly elongated pulse durations, provides a solution that can effectively utilize the UWB spectrum. Our approach is based on the idea of conflict resolution using binary ‘something’/‘nothing’feedback, which has not been widely studied in wireless and specifically in UWB networks. Our protocol unites binary conflict resolution and multi-band utilization to effectively utilize the available bandwidth. To ensure that our proposed approach is tightly knit with the underlying physical layer, we discuss physical–layer dependencies and the conformance to FCC-imposed emission limits. We evaluate our approach via extensive simulations. Our simulation results demonstrate the significant advantages of our approach over single-band solutions: the throughput increases significantly, and the number of collisions decreases considerably. Copyright © 2006 John Wiley & Sons, Ltd.