ADC ETU-751C - Manual (Page 13)

700-701-100-02 Overview
UTU-701 and ETU-751 List 1 August 9, 2002 3
Figure 1. Leased Line Data Application on a Single-pair G.703 Network
HDSL T
ECHNOLOGY
HDSL is the core technology for ADC’s WorldDSL 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. ADC’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) using this 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 Table 2 .
The no noise transmission ranges are listed in “Specifications” on page 9 .
‘
Table 2. Transmission Ranges with 0 db ETSI Noise
RS G.703 HDSL Payload Rate Wire Size and Transmission Range (with 0 dB ETSI Noise)
User Selected
HDSL Payload
Rate (kbps)
Actual
HDSL Payload
Rate (kbps) (a)
0.4mm (26 AWG)
Single Twisted-Pair
Copper Wire
0.51mm (24 AWG) Single
Twisted-Pair Copper Wire
64/128 256 4.1 km (13,451 ft.) 5.1 km (16,730 ft.)
256 384 3.6 km (11,811 ft.) 4.7 km (15,420 ft.)
384 512 3.4 km (11,155 ft.) 4.5 km (14,760 ft.)
640 768 3.0 km (9,842 ft.) 4.2 km (13,779 ft.)
1024 1152 2.6 km (8,530 ft.) 3.4 km (11,155 ft.)
1408 1536 2.2 km (7,218 ft.) 2.9 km (9,515 ft.)
1920/1984/2048 2048 (b) 2.0 km (6,562 ft.) 2.4 km (7,874 ft.)
(a) See “G.704 Framing and Rate Selectable HDSL” on page 17 .
(b) System operates in unstructured mode when 32 time slots are selected.
(b) The maximum no-noise transmission range is approximately 7.1 km (4.4 miles). See
“Specifications” on page 9 .
Network Side
Customer Side
Exchange
Office
DTE
HDSL
Single Pair
HDSL loop
UTU-701
(LTU)
UTU-701
(NTU)
G.703
HDSL
Customer
DTE
Time Slots 1 through 4
+Time Slots 0 and 16
G.703
(256 kbps)
4 Time Slots
(256 kbps)
4 Time Slots
(384 kbps)
PC