Addressing Deafness Problems in Wireless Ad-hoc Networks with Directional Antennas
Kai Chen, Fan Jiang · 2007
Directional antennas have tremendous potential for improving the performance of wireless ad-hoc networks. While offering higher spatial reutilization and larger transmission range, they also pose new challenges. Deafness is one of such problems that hard to be treated. This paper proposes a new Rotary DMAC with Deafness Mitigation (RDMAC/DM) protocol to address the deafness in directional systems. We first make a relatively comprehensive exploration about the deafness problems arisen in directional scenarios. Equipped with the newly introduced Start Of Transmitting/Receiving (SOT/SOR) packets and Deafness Allocation Vector (DAV), RDMAC/DM can better deal with the difficulties, such as early-reservation and unnecessary lock, when inheriting the traditional IEEE 802.11 schemes into directional MAC protocols, which are left poorly addressed previously. Moreover, we propose a smart Forwarding Message (FM) to alleviate the stalwart deafness problem due to the unheard RTS-CTS. Simulation results indicate that RDMAC/DM can effectively mitigate the identified deafness problems, and outperform the existing directional MAC protocols and IEEE 802.11.