Wideband Data on T1 Carrier

Since its manufacturing began in 1962, the T1 Carrier System 1 has been widely accepted by Bell System operating companies as an economic system of high performance for the transmission of voice signals in interoffice trunks. Although its use is growing and will continue to grow for voice transmission, it is significant that the T1 carrier regenerative repeatered line 2 with its 1.544 megabit per second transmission capability is introducing into the Bell System the first common carrier high-speed digital transmission facility. Its potential use as a facility for the growing market of wideband data transmission is apparent. Because the T1 carrier system was primarily developed for interoffice trunks of the exchange and toll connecting type its repeatered line design has been optimized for comparatively short haul use from the standpoint of the economics of installation and maintenance. Although distances of 200 miles or more may be obtainable, repeatered line installations have generally not exceeded 50 miles. Thus, it may be expected that initial use of T1 carrier as a wideband data facility will be emphasized for two general applications: (i) As an extension of interexchange wideband circuits into the exchange plant, and 1567