Communications. I. Fiber optics

The Bell System has made major commitments to both the manufacture and installation of fiber-optic systems as an economic alternative to wire cable. These digital systems, operating mainly at 44.7 Mb/s, transmit voice, data, and video at 820-nm wavelengths over trunk lines that connect to central offices. They are being tested by the telephone operating companies of Bell in Chicago, New York City, Trumbull, Conn., and elsewhere.