Exact throughput capacity in MANETs with directional antenna and transmission power constraint

A major obstacle stunting the application of mobile ad hoc networks (MANETs) is the lack of a general throughput capacity theory for such networks. Available works in this area mainly focused on exploring the order sense scaling laws of throughput capacity in MANETs with omnidirectional antennas or that of static ad hoc networks with directional antennas. Although the order sense results can help us to understand the general scaling behaviors, it tells us little about the exact throughput capacity. Another limitation of available works is that the impact of transmission power constraint on the throughput capacity is largely neglected. In most MANET applications, however, the mobile nodes are usually powered by batteries and have limited transmission power. In this paper, we study the exact throughput capacity of MANETs with directional antenna and transmission power constraint, where a generalized twohop relay algorithm with limited packet redundancy is adopted for packet routing. For given transmission power constraint, we first develop a model to map the omnidirectional transmission range to that of the directional one. We then explore the exact throughput capacity under directional transmission and group-based scheduling. Finally, numerical studies are provided to demonstrate the efficiency of these models and validate our theoretical results.