Chapter 2
17
2.11 ADSL Transmission
The ADSL transmission is based on ITU G.dmt, UAWG, G.lite and ANSI
T1.413 standard DMT line codes. The device’s DMT line rate is up to 8 Mbps
downstream and up to 1 Mbps upstream. The DMT transceiver is rate adaptive
and capable of providing faster rates over shorter distances and slower rates
over longer distances. The ADSL device’s transceiver can adjust to changing
line conditions to maximize the data throughput over the given distance. Rate
adaptation is supported in increments of 32 kbps.
A Service Provider will set the ADSL device’s data-rates at the DSLAM
network interface depending on the service contract the subscriber buys. The
upstream and downstream rates can be set in various ways:
• Maximum bit rate
• Minimum bit rate
• A range between minimum and maximum bit rates
• Maximum bit rate with a threshold in Decibels (dB)
2.12 ATM Transmission
ATM over ADSL transmission is based on ITU G.DMT, UWAG, G.Lite and
ANSI standard T1.413, Issue 2, standards incorporating ADSL Forum TR-0002
“ATM over ADSL Recommendations”.
