Mr. John C. Wohlstetter, a Washington attorney, is director of technology affairs for GTE Service Corporation. His primary responsibility at GTE is strategic assessment of technology, regulatory, and market trends. From 1986 to 1988, he served as senior advisor to the Committee on Review of Synchronization, Switching, and Network Control in National Security Telecommunications. Its report, Growing Vulnerability of the Public Switched Networks: Implications for National Security Emergency Preparedness, was issued by the National Research Council, the operating arm of the National Academy of Sciences. He has 20 years of experience in the telecom industry with Contel and then with GTE.