The design goal of communication networks is to transport information from a generating source to an intended destination. Of the many ways this can be accomplished, there are networks designed to maximize properly selected optimality criteria. This talk is concerned with basic principles governing the associated optimization problem for wireless communication networks in the presence of fading. While it is widely believed that the conventional protocol stack results in poorly performing wireless networks it will be shown that in the presence of fading separating the design of wireless networks in layers can be optimal. This result is a consequence of the fact that even though the associated optimization problem is generally non-convex the gap with its Lagrange dual problem is zero. Further consequences of this latter property pertaining to physical layer optimization will also be discussed.
Alejandro Ribeiro has been an Assistant Professor at the department of Electrical & Systems Engineering at the University of Pennsylvania, Philadelphia, PA since July 2008. He received his B.Sc. degree in Electrical Engineering from Universidad de la Republica Oriental del Uruguay, Montevideo, Uruguay in 1998. Between 2003 and 2008 he was at the Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN where he received his M.Sc. and Ph. D. degrees in Electrical Engineering in May 2005 and May 2007. From 1998 to 2003 he was a member of the Technical Staff at Bellsouth Montevideo. His research interests lie in the areas of communication, signal processing and networking. His current research focuses on wireless communications and networking, distributed signal processing and wireless sensor networks. Dr. Ribeiro received best student paper awards at ICASSP 2005 and ICASSP 2006. Mr. Ribeiro is a Fulbright Scholar.