Abstract

ABSTRACT The key aspect in the design of any contention-based medium access control (MAC) protocol is the mechanism to measure and resolve simultaneous contention. Generally, terrestrial wireless MACs can only observe success or collision of a contention attempt through carrier sense. An implicit estimate of the number of contenders occurs through repeated observation and changing back-o contention window. Recent work in underwater MAC protocols suggest there it is possible to directly count the number of contenders by exploiting the spatio-temporal uncertainty inherent to high-latency underwater acoustic medium. Prior work has shown how to use counting in underwater MACs, and how to optimize contention windows in radio MACs. In this paper, we quantify bounds to convergence time for MAC protocols employing exact contender counting. We show that perfect counting allows contention to converge quickly, independent of network density, with an asymptotic limit of 3.6 contention rounds on average. We conrm this analysis with simulation of a specic underwater MAC protocol, and suggest the opportunity for the results to generalize for any radio-based MACs that estimate contenders.