A Distributed Directional-to-Directional MAC Protocol for Asynchronous Ad Hoc Networks

The use of directional antennae in ad hoc networks has received growing attention in recent years. However, most existing directional MAC protocols assume interchangeable directional and omni-directional modes of operation. Such operation reduces the spatial gain and introduces the asymmetry-in-gain problem. In this paper, the authors propose a Directional-to-Directional (DtD) MAC protocol for ad-hoc networks that operates in the directional mode exclusively. The protocol is fully distributed, does not require any synchronization, eliminates the asymmetry in-gain problem, and alleviates the deafness problem.