700-712-100-01, Revision 01
Overview
UTU-712 and ETU-762 List 1
May 10, 1999
3
HDSL T
ECHNOLOGY
HDSL is the core technology for PairGain’s HiGain-ETSI line of LTUs, UTUs, and ETUs. Rate selectable HDSL
enables these units to transmit and receive digital data at various rates over various distances on one twisted-pair
of copper wire. Both outbound and inbound signals are delivered on the same pair of wires by using echo
cancellation techniques. The transmitted signal is canceled at the receiver by precisely predicting the amount of
signal echo, then subtracting it from the overall input signal. PairGain’s market leading HDSL-based products
tolerate crosstalk, and operate not only on continuous unobstructed pairs of wires, but also on cables with mixed
wire gauges and bridged taps.
T
RANSMISSION
R
ANGES
Transmission ranges assume the presence of noise according to the ETSI model described in TS 101 135. The
expected Bit Error Rate (BER) under this noise model is 1x10
-7
. The transmission ranges in such a noise
environment at the various HDSL line rates over one twisted-pair of 0.4 mm and 0.51 mm copper wire are listed
in
. The no noise transmission ranges are listed in
.
‘
Table 2.
Transmission Ranges with ETSI Noise
Wire Size and Transmission Range (with ETSI Noise)
HDSL Line
Rate (kbps)
(a)
0.4 mm (26 AWG)
Single Twisted-Pair
Copper Wire
0.51 mm (24 AWG) Single
Twisted-Pair Copper Wire
128
5.0 km (16,404 ft.)
6.3 km (20,669 ft.)
256
4.1 km (13,451 ft.)
5.1 km (16,732 ft.)
384
3.9 km (12,795 ft.)
4.7 km (15,420 ft.)
512
3.5 km (11,483 ft.)
4.5 km (14,764 ft.)
768
3.2 km (10,499 ft.)
4.2 km (13,779 ft.)
(a) A selected HDSL line rate of 64 kbps is transmitted at 128 kbps.