t several of these kinds of systems, using different wide-band carriers, could operate simultaneously in the same band with little effect on each other. This concept, which, it is noted, would eliminate the cooperative synchronization required in time-division multiple-access (TDMA) systems, is one of the earliest references to CDMA operation. While the authorship of Appendix G is not indicated explicitly in the Hartwell report, it is clear that the main contributors to this portion of the study effort were Jerome B. Wiesner, Edward E. David, Harald T. Friis, and Ralph K. Potter. Wiesner and David went on from M.I.T. to become science advisers to President Kennedy and Nixon, respectively. Friis and Potter were already well-known for their accomplishments at BTL, the latter being a prime innovator of the X-System [58]. There is considerable evidence that Wiesner, then professor of electrical engineering and Associate Director of RLE at M.I.T., was the author of Appendix G, and most likely the source of the TR-SS and SS-CDMA concepts set forth in this report [3]. Concerning Wiesner's place in the development of modern communica- tions, it was later said by an M.I.T. professor [133], "Perhaps one might put it that Wiener preached the gospel and Wiesner organized the church. Jerry's real strength lies in his ability to spot the potential importance of an idea long before others do." Certainly Wiesner appreciated the possibilities of the wide-band commu- nication systems discussed at Hartwell. Shortly after Hartwell, Wiesner met Robet Fano in a hallway near the Building 20 bridge entrance to the RLE secret research area and told Fano of a "Navy study idea" for using a noise- modulated carrier to provide secure military communications. Even though Fano was familiar with Shannon's precepts and had been an early contrib- utor to the new field of information theory, this made a profound impres- sion on him. He in turn discussed the concept with Wilbur Davenport, a then recent recipient of the Sc.D. degree from M.I.T. They