Cross-Layer Optimal Policies for Spatial Diversity Relaying in Mobile Ad Hoc Networks

In order to adapt to time-varying wireless channels, various channel-adaptive schemes have been proposed to exploit inherent spatial diversity in mobile/wireless ad hoc networks where there are usually alternate next-hop relays available at a given forwarding node. However, current schemes along this line are designed based on heuristics, implying room for performance enhancement. Thereby, to seek a theoretical foundation for improving spatial diversity gain, we formulate the selection of the next-hop as a sequential decision problem and propose a general "Optimal Stopping Relaying (OSR)" framework for designing such next-hop diversity schemes. As a particular example, assuming Rayleigh fading channels, we implement an OSR strategy to optimize information efficiency (IE) in a protocol stack consisting of Greedy Perimeter Stateless Routing (GPSR) and IEEE 802.11 MAC protocols. We present mathematical analysis of the proposed OSR together with other strategies in the literatur...

• Type: Journal
• Year: 2008
• Where: TWC
• Authors: Jing Ai, Alhussein A. Abouzeid, Zhenzhen Ye
• Keywords: Forwarding Node, Spatial Diversity, Time-varying Wireless Channels, TWC 2008