1. two-binary, one-quaternary 2B1Q A physical layer encoding used for Integrated Services Digital Network basic rate interface. 2B1Q represents two bits 2B - a "dibit" using one of four signal levels 1Q - a "quadratude". The first bit of the dibit is indicated by polarity: positive indicates a binary 1 and negative indicates a 0. The second half of the dibit is indicated by voltage magnitude: 1 Volt indicates a binary 1 and 3 Volts indicates binary 0.
two-binary, one-quaternary |
