L5 system: Centralized transmission surveillance

A centralized and automated transmission surveillance system has been developed for the L5 Coaxial-Carrier Transmission System as a means for attaining desired transmission reliability. Additional benefits are extensive and include accurate data-processing capabilities plus substantial cost and time economies. The system consists of two basic measuring and control facilities: (i) a transmission surveillance center, located at a designated main station, originates all control operations and accumulates and processes all measured data through use of a small computer, and (ii) transmission surveillance auxiliaries, located at all other main stations, perform measurement functions as directed and return the resulting raw data to the controlling transmission surveillance center. Digitally operated test equipment makes desired measurements under local or remote programmed control, and the E2 Status Reporting and Control System provides interstation transmission of commands and data through time-sharing of a four-wire data transmission link.