From 1977 to 1982 he was an Assistant Professor, and from 1982 to 1984 an Associate Professor, in the Department of Mathematics at the University of Maryland, Baltimore County. Since 1985 he has been at the University of Illinois, Urbana-Champaign, where he is currently Franklin W. Woeltge Professor of Electrical and Computer Engineering, and a Research Professor in the Coordinated Science Laboratory.
He has worked on problems in game theory, adaptive control, stochastic systems, simulated annealing, neural networks, machine learning, queuing networks, manufacturing systems, scheduling, and wafer fabrication plants. His current research interests are in wireless networks, sensor networks, and the convergence of control, communication and computation.
He serves as Editorial Board of many foundations and as Editor and Associate Editor of a large number of international journals. He has presented plenary lectures at international conferences (IEEE, SIAM) and he is a coauthor of the book, Stochastic Systems: Estimation, Identification and Adaptive Control, with Pravin P. Varaiya, and the monograph, Scaling Laws for Ad Hoc Wireless Networks: An Information Theoretic Approach, co-authored with Feng Xue.
He is a Fellow of the IEEE since 1988, a recipient of the Donald P. Eckman Award of the American Automatic Control Council in 1985, the 2006 IEEE Field Award in Control Systems, the 2007 IEEE Communications Society Fred W. Ellersick Prize, and a member of the National Academy of Engineering, U.S.A. since 2007.