This volume presents lectures delivered at a workshop held at the Chinese Academy of Sciences (Bejing). The following articles are included: "Nonlinear Systems Control" by R. Brockett, "Adaptive Control of Discrete-Time Nonlinear Systems with Structural Uncertainties" by L.-L. Xie and L. Guo, "Networks and Learning" by P. R. Kumar, "Mathematical Aspects of the Power Control Problem in Mobile Communication Systems" by C. W. Sung and W. S. Wong, and "Brockett's Problem on Nonlinear Filtering Theory" by S. S.-T. Yau. Basic concepts and current research are both presented in this book. The volume offers a comprehensive and easy-to-follow account of many fundamental issues in this diverse field. It would be a suitable text for a graduate course on wireless communication. Titles in this series are co-published with International Press, Cambridge, MA.