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<XML><RECORDS>
<RECORD>
	<REFERENCE_TYPE>0</REFERENCE_TYPE>
	<AUTHORS>
		<AUTHOR>Jing Ai, A. A. Abouzeid, Zhenzhen Ye</AUTHOR>
	</AUTHORS>
	<YEAR>2008</YEAR>
	<TITLE>Cross-layer Optimal Policies for Spatial Diversity Relaying in Mobile Ad Hoc Networks</TITLE>
	<SECONDARY_TITLE>IEEE Transactions on Wireless Communications</SECONDARY_TITLE>
	<PUBLISHER>IEEE</PUBLISHER>
	<VOLUME>7</VOLUME>
	<NUMBER>8</NUMBER>
	<PAGES>2930-2939</PAGES>
	<DATE>08/2008</DATE>
	<ABSTRACT>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. 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 &quot;optimal stopping relaying (OSR)&quot; 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 literature for a single forwarding node. In addition, we perform extensive simulations (using QualNet) to evaluate the end-to-end performance of these relaying strategies in a multi-hop network. Both the mathematical and simulation results demonstrate the superiority of OSR over other existing schemes.</ABSTRACT>
	<URL>http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4600206</URL>
</RECORD>
</RECORDS></XML>