Considerations for a new military radio relay system

PRIOR to World War II, the Armed Forces' need for multitelephone channel trunk circuits was satisfied by the use of metallic wire circuits. Early in the war, it was demonstrated that the fluidity of movement which accompanied blitz-type warfare required a more rapid means of providing multichannel trunk facilities than could be had with wire circuits. As a result, military radio relay equipment operating in the very-high-frequency range was developed early in 1942, capable of providing rapidly installable transmission facilities for four frequency-division multiplexed voice channels. This equipment was used successfully in all theaters of operation throughout World War II, conclusively demonstrating the tactical advantages of this type of transmission facility. In addition, 8-channel microwave equipment, using time-division principles of multiplexing, was developed for use at high echelons of command.