Tele-Communication (Telecom) Terms Glossary and Dictionary
Bipolar encoding is a type of line code (a method of encoding digital information to make it resistant to certain forms of signal loss during transmission). A binary 0 is encoded as zero volts as in unipolar encoding. A binary 1 is encoded alternately as a positive voltage and a negative voltage. This prevents a significant build-up of DC, as the positive and negative pulses average to zero volts. Little or no DC-component is considered an advantage because the cable may then be used for longer distances and to carry power for intermediate equipment such as line repeaters. The DC-component can be easily and cheaply removed before the signal reaches the decoding circuitry.