FT3—A metropolitan trunk lightwave system

FT3 is a 44.7 Mbit/s (DS3) digital lightwave transmission system intended primarily for metropolitan trunking. The system terminal includes a new multiplex, MX3, which provides interfaces for lower rate DS1, DS1C, or DS2 signals. The multiplex and lightwave line terminal are integrated into a single equipment configuration. Regenerators, containing laser transmitters and APD receivers, are spaced at approximately 4-mi intervals. A ribbon structured cable, containing up to 144 fibers, provides a maximum system capacity of about 40000 voice circuits. System parameters, maintenance, and performance features are consistent with requirements imposed by metropolitan digital trunk networks. The first fully standard application is planned for Atlanta, GA in December 1980, with several early follow-on applications already committed.