Handling Asymmetry in Gain in Directional Antenna Equipped Ad Hoc Networks

Conference: PIMRC 2005 - 16th Annual IEEE International Symposium on Personal Indoor and Mobile Radio Communications
09/11/2005 - 09/14/2005 at Berlin, Germany

Proceedings: PIMRC 2005

Pages: 5Language: englishTyp: PDF

Personal VDE Members are entitled to a 10% discount on this title

Jakllari, Gentian; Broustis, Ioannis; Krishnamurthy, Srikanth V. (Department of Computer Science & Engineering, University of California, Riverside, Riverside, CA 92521, USA)
Korakis, Thanasis; Tassiulas, Leandros (Department of Computer Engineering and Telecommunications, University of Thessaly, 38221 Volos, Greece)

The deployment of traditional higher layer protocols (especially the IEEE 802.11 MAC protocol at the MAC layer) with directional antennae could lead to problems from an increased number of collisions; this effect is primarily seen due to three specific effects: (i) an increase in the number of hidden .terminals; (ii) the problem of deafness and, (iii) a difficulty in determining the locations of neighbors. In this work we propose a new MAC protocol that incorporates circular RTS and CTS transmissions. We show that the circular transmission of the control messages helps avoid collisions of both DATA and ACK packets from hidden terminals. Our protocol intelligently determines the directions in which the control messages ought to be transmitted so as to eliminate redundant transmissions in any given direction. We perform extensive simulations and analyze the obtained results in order to compare our scheme with previously proposed protocols that have been proposed for use in directional antenna equipped ad hoc networks. Our simulation results clearly demonstrate the benefits of incorporating both circular RTS and CTS messages in terms of the achieved aggregate throughput.