2B1Q

From Wikipedia, the free encyclopedia

Two-binary, one-quaternary (2B1Q) is a physical layer encoding used for Integrated Services Digital Network (ISDN) basic rate interface. 2B1Q uses four signal levels, which are -450 mV, -150 mV, 150 mV and 450 mV, each (1Q) equivalent to two bits (2B). A competing encoding technique, also used for ISDN basic rate interfaces, is 4B3T.

This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.