Symmetric Digital Subscriber Line allows broadband data
services to be carried on conventional copper pair telephone cables.
Symmetric Digital Subscriber Line is a single-pair alternative to HDSL, providing
data rates (or speed) up to 1 Mbps duplex (i.e.
for both upstream and downstream traffic).
The term "symmetric" in ADSL
refers to the difference in uplink and downlink capacities; the
same capacity is provided for the downlink as for the
uplink. This means that the same number of tones are
allocated for downlink data as for uplink data.
Symmetric Digital Subscriber Line
is based on an adaptive, multi-tone modulation system. Each tone
carries a part of either the uplink or the downlink
bitstream. Because the bitstreams are split across a number of
tones, the symbol rate on the link is much less
than the bit rate.
Other topics in our resources on Broadband Internet related to Symmetric Digital Subscriber Line include: