E1 line (E1)

The E1 line (E1) is an E- transmission interface based on the PDH multiplex structure. It has the primary rate of 2048 kbit/s in Europe.

E1 is also known as CEPT1 and has 30 user channels at 64 kbit/s for the transmission of voice and data, plus a signaling channel at 64 kbit/s and a service and maintenance channel also at 64 kbit/s.

The further multiplex hierarchy is based in each case on a quadrupling of the data rates. Thus, the E2 transmission interface has a data rate of 8.448 Mbit/s, E3 one of 34.368 Mbit/s, that of E4 is 139.264 Mbit/s, and that of E5 565.148 Mbit/s.