E1

from The Free On-line Dictionary of Computing (8 July 2008)

E1

   <communications> A European {framing specification} for the
   transmission of 32 {DS0} (64 kb/s) data streams.  By
   extension, it can also denote the transmission rate required
   (2.048 Mb/s = 2048 kb/s).  Unlike {DS1} it is free of
   {bit-robbing}.

   (2002-03-22)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

E1
       European digital transmission format 1 [2.048 Mbps]