T
T1
Definition
An AT&T Bell Labs term originally used in 1962 for the first digitally multiplexed transmission system for voice signals. Present day use indicates a digital carrier facility used to transmit a digital signal 1 or DS1 formatted digital signal at 1.544 megabits per second. This is equivalent to 24 analog lines. T1 transmission uses a bipolar Return To Zero alternate mark inversion line coding scheme.