G.992.1
Sign in to saveIn telecommunications, ITU-T G.992.1 (better known as G.dmt) is an ITU standard for ADSL using discrete multitone modulation (DMT). G.dmt full-rate ADSL expands the usable bandwidth of existing copper telephone lines, delivering high-speed data communications at rates up to 8 Mbit/s downstream and 1.3 Mbit/s upstream.
~14 min read
Encyclopedic overview
14 sectionsContents
- DMT history and line rates
- DMT technical details
- Bins (carrier channels)
- Coded orthogonal frequency-division multiplexing (COFDM)
- Reducing bit errors with QAM or PSK
- Bin quality and bit rate
- Echo cancellation
- DMT bits-per-bin examples
- Textual
- Graphical with SNR
- Summary
- ADSL statistics
- External links
- References
In telecommunications, ITU-T G.992.1 (better known as G.dmt) is an ITU standard for ADSL using discrete multitone modulation (DMT). G.dmt full-rate ADSL expands the usable bandwidth of existing copper telephone lines, delivering high-speed data communications at rates up to 8 Mbit/s downstream and 1.3 Mbit/s upstream.
DMT allocates from 2 to 15 bits per channel (bin). As line conditions change, bit swapping allows the modem to swap bits around different channels, without retraining, as each channel becomes more or less capable. If bit swapping is disabled then this does not happen and the modem needs to retrain in order to adapt to changing line conditions.
Excerpted from Wikipedia’s “G.992.1” article, available under the CC BY-SA 4.0 licence.