Newsletter
The Black Box website uses cookies.
By continuing the use of the Black Box website, or by pressing the agree button on the right, you consent to the use of cookies on this website. More information.
Home > Resources > Technical Resources > Black Box Explains > WAN > Some line encoding techniques used by DSL.
Navigation
 
Some line encoding techniques used by DSL.

2B1Q — 2 Binary 1 Quaternary; for ISDN DSL (IDSL); sends two bits of data to every one cycle of an analogue waveform. Uses frequencies of up to 80,000 Hz; same encoding is used on ISDN lines.

QAM — Quadrature Amplitude and Phase Modulation; used in modems for more than 20 years.

CAP — Carrierless Amplitude and Phase modulation. Similar to QAM.

DMT — Discrete MultiTone; patented by AT&T Bell Labs more than 20 years ago.

Share |