Inventors:
John W. Hicks - Boston MA
International Classification:
H04B 900
Abstract:
An optical communications systems, e. g. a telephone system, comprising means to accept even electrical communication signals from transmitting stations, modulate an optical signal with said signal from the transmitting station and, using time-division-multiplexing (TDM), provide a resultant optical communication signal to a central station which utilizes a frequency-division-multiplexing (FDM) system for handling incoming optical signals before passing the optical communication signals on to a receiving station which utilizes time-division-demultiplexing means and, where necessary, reconverts the optical signal to an electrical communication signal. Particular advantages of the system are that it can handle and switch a very large number of signals and that it can be utilized in a hybrid communications system wherein, for example, users of the system can maintain conventional electrical entrance wiring connections and conventional non-optical telephones and yet interface readily with optical street lines of the system. Particular aspects of the invention are novel modulating and signal-selection devices.