A New Method for Frequency-Division Multiplexing, and Its Integration with Time-Division Switching

A new method to achieve frequency-division multiplexing has been determined. The basis of this method is a new heterodyning scheme, which operates in conjunction with a generalized concept of resonant transfer. Besides achieving frequency-division multiplexing, these concepts, in combination with time-division switching, are the basis for a system that seems to be more economical than conventional combinations of these capabilities. Such a combination is required to effect time-division switching into and out of frequency-divided trunk lines. The basic reason that this integrated system offers the potential of such economy is that the time-division switches are made to serve two purposes. In addition to performing their normal switching function, they also serve a purpose in the frequency multiplexing and demultiplexing operations. Laboratory analysis and development have thus far validated the feasibility of these concepts.