Channel-Adaptive Relaying in Mobile Ad Hoc Networks with Fading

Published

October 1, 2005

Author(s)

Michael R. Souryal, Nader Moayeri

Abstract

This paper describes an approach for relaying in multihop networks that adapts to the time-varying channel and exploits spatial diversity to mitigate multipath fading. Ignored in some simulation-based performance analyses, fading arises from multipath propagation and causes fluctuations in the signal strength in mobile networks, adversely affecting communication performance. Our approach uses limited cross-layer interactions between the physical, link and routing layers to provide adaptivity to both large and small-scale channel effects and to achieve spatial diversity gain without the use of multiple antennas. The routing layer uses long-term measurements of link quality in the form of the average signal-to-noise ratio (SNR) to opportunistically select next-hop relays on a hop-by-hop basis. Small-scale variations are overcome at the MAC layer through efficient multicast polling of multiple next-hop candidate relays prior to data transmission. A performance analysis for networks employing geographic routing and an IEEE 802.11-based MAC (i) demonstrates significant improvements in network capacity and end-to-end delay achieved with these channel-adaptive techniques in Rayleigh and Ricean fading environments, (ii) shows that most of the small-scale diversity gain is obtained through the use of only two next-hop relay choices, and (iii) assesses the practical limit of the short-term adaptive component in terms of maximum node velocity.

Proceedings Title

Proceedings of the IEEE Conference on Sensor and Ad Hoc Communications and Networks (SECON)

Conference Dates

September 26-29, 2005

Conference Location

September 26-29,

Conference Title

IEEE Conference on Sensor and Ad Hoc Communications and Networks

Pub Type

Conferences

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Keywords

ad hoc network, adaptive routing, cross-layer, fading, IEEE 802.11

Citation

Souryal, M. and Moayeri, N. (2005), Channel-Adaptive Relaying in Mobile Ad Hoc Networks with Fading, Proceedings of the IEEE Conference on Sensor and Ad Hoc Communications and Networks (SECON), September 26-29, , [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=150119 (Accessed April 18, 2024)