The n2 carrier terminal — objectives and analysis

The N2 carrier terminal, a 12-channel, double-sideband, amplitude modulated multiplex, is the first of a new family of short-haul carrier facilities. The new carrier family is designed to take advantage of improvements possible with solid-state technology and to meet changing needs of the growing Bell System toll network. Increased demands on the short-haul trunks have resulted from the growth of voice and nonvoice services on the DDD network, tightening requirements such as those for over-all net loss variations between channels and gain variations across the channel frequency band. Maintenance and operational features of short-haul facilities also are affected by the increase in complexity and size of the Bell System carrier network: newer equipment must have fewer adjustments, and the design must provide built-in margins to permit longer maintenance intervals and more effective alarm and trunk processing features in case of failure. The new carrier family must compete economically with existing short-haul systems, yet work with in-place carrier systems and facilities. The new terminal meets the above objectives. In addition, improvements in the performance of N-carrier repeatered lines are indicated as a result of the systems analysis of short-haul carrier systems which led to the requirements for the N2 terminal.