The use of directional antennas in support of ad hoc networks has been considered a promising alternative to improve spatial division multiple access and throughput. In general, directional Medium Access Control (MAC) protocols are based on IEEE 802.11 standard, which was designed for omnidirectional communication. When applied to di- rectional communication, the standard imposes a number of constraints to the directional MAC protocol. In order to harvest the benefits of directional communications, MAC pro- tocols tailored for directional antennas have to be devised. In particular, MAC protocols that are able to deal with deafness and channel reservation latency are highly desirable. This work proposes a technique that enables channel reservation and mitigates deafness using pulse/tone signals in the context of directional communications. At its heart, the proposed technique incorporates a deafness predictions scheme that helps nodes to over- come its effects. Analytical results show that the proposed technique is able to improve throughput up to 40% when compared to other prominent directional MAC protocols. Simulation results show that the proposed scheme improves fairness and throughput up to 350% and 76%, respectively.
Directional Pulse/Tone Based Channel Reservation with Deafness Avoidance