E3 line (E3)
The E3 line (E3) is an E- transmission interface based on the PDH multiplex structure, which is 64 kbit/s in Europe and determines the data rates in a four-fold multiplex hierarchy.
The E3 channel corresponds to four times the value of the lower- order line E2, and so on. E3 has a data rate of 34.368 Mbit/s, which results from quadrupling E2's data rate of 8.448 Mbit/s. E2, in turn, results from quadrupling E1 's data rate of 2.048 Mbit/s. The E3 data transmission frame is 1536 bits long and consists of 4 subframes of 384 bits each.