A new high-capacity microwave relay system

The increase in demand for communication service throughout the world has exceeded the rate of growth in population and the tremendous expansion of industrial activities.1 Both civilian and military requirements have grown beyond the expectations of those associated with the communication field. Along with this need for increased capacities in communication networks, the need has developed for more reliable, higher quality communication service. Military operations and the defense of a country are dependent on the ability to communicate rapidly and accurately. Likewise the operations of large industrial organizations are controlled by signals transmitted over long distances. With these factors in view the MM-600 radio relay system described in this paper was developed. It is intended for use in major communication networks to transmit large numbers of signals from one central location to another over distances up to 4,000 miles. It was designed for common-carrier-type applications where reliability, excellence of performance, and ease of maintenance are of paramount importance. New components such as travelling-wave tubes and solid state devices plus new concepts such as computer techniques have been integrated into proven methods to fulfill these requirements.