PERFORMANCE ANALYSIS OF ULTRA WIDEBAND MEDIA ACCESS CONTROL PROTOCOL PROVIDING TWO CLASS TRAFFIC

Abstract

UWB (Ultra wideband) technology has a huge potential for revolutionizing the world of digital communications, particularly wireless communications that based primarily on the impulse radio paradigm. UWB technology was originally seen purely as a physical layer technology, with no or little protocol to control the communication. It is now clear that Media Access Control (MAC) features play a major role in UWB communication systems. In this paper, a communication system is considered with a small number of geographically separated nodes in UWB ad hoc networks. An active node can be in one of two possible classes (H,L); high priority or low priority class, depending on its nature and / or the type of information that it desires to transmit. Nodes in class-H are given some priority over those in class-L. The motivation comes from the observation that, 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 which amounts to 60 ns in indoor environments. Therefore, using a wider frequency band to shorten the transmission time for each pulse may not increase the data rate in proportion to the available bandwidth. Thus, a multiband approach is considered to better utilize the available spectrum, where each transmitter sends longer pulses in one of many narrower frequency bands. Measures of system performance including throughput, average delay and bit error rate will be presented in single band and multiband approaches. Additionally, there is a comparison between numerical results and how they are achieved by simulation of the entire system providing two priority classes.