Channels and transmission rates

T1 and E1 are four-wire digital transmission links. T1 is used mainly in the United States, Canada, Hong Kong, and Japan. E1 is used in Europe.

Data on a T1 or E1 trunk is transmitted in channels. Each channel carries information digitized at 64,000 bits per second (b/s). This transmission rate is called the digital signal level 0 (DS-0) rate.

T1 carries 24 channels. E1 carries 32 channels. The total throughput rate (called digital signal level 1 or DS-1) is: