The T1 Carrier System

The rapid expansion in the telephone network that has occurred since 1950 has stimulated a thorough investigation of methods for reducing the cost of additional trunk facilities. The desire to improve the quality of telephone service has given additional emphasis to studies of improved trunking arrangements. One way to obtain additional trunks for growth is to increase the utilization of existing conductors by using them to transmit more than one voice signal. For such an arrangement to be economical, the savings from the more efficient use of the transmission line must more than offset the cost of the terminal equipment required to multiplex a number of voice channels. On trunks between cities, carrier systems (systems transmitting a number of voice channels) have been economical for many years. The lower terminal costs achieved in the Tl carrier system 1405 ( TERMINAL SPAN I REPEATER S E C T I O N LINE I REPEATER SECTION H