Roger L. Freeman is founder and Principal of Roger Freeman Associates, independent consultants in telecommunications, specializing in systems engineering in the United States, Canada, and Hispanic America. In the course of over forty-five years' experience in telecommunications operations, maintenance, and engineering, he has served as principal engineer for advanced system planning at the Raytheon Company, technical manager for ITT Marine Europe, and regional planning expert for the International Telecommunications Union (ITU), among other positions. In addition to the previous edition of Radio System Design, Mr. Freeman has written six other popular books on various aspects of telecommunications engineering: Reference Manual for Telecommunications Engineering, Third Edition; Fiber-Optic Systems for Telecommunications; Telecommunication System Engineering, Fourth Edition; Fundamentals of Telecommunications, Second Edition; Practical Data Communications, Second Edition; and Telecommunications Transmission Handbook, Fourth Edition, all published by Wiley. A senior life member of the IEEE, Mr. Freeman has lectured at numerous professional conferences and published widely in international telecommunication journals.