To see the relationship between the E-carrier system, the T-carrier
system, and DS0 multiples, see digital
signal X.
E1 (or E-1) is a European digital transmission format devised by the
ITU-TS and given the name by the Conference of European Postal and Telecommunication
Administration (CEPT). It's the equivalent of the North American T-carrier
system format. E2 through E5 are carriers in increasing multiples of
the E1 format.
The E1 signal format carries data at a rate of 2.048 million
bits per second and can carry 32 channels of 64 Kbps*
each. E1 carries at a somewhat higher data rate than T-1
(which carries 1.544 million bits per second) because,
unlike T-1, it does not do bit-robbing and
all eight bits per channel are used to code the signal. E1 and T-1
can be interconnected for international use.