Section 150-431-114
Release 01
Page 2
A. PRODUCT OVERVIEW
(Doubler and Non-Doubler)
1. DESCRIPTION AND FEATURES
1.01
PairGain’s HiGain Line Unit Model HLU-431
List 1D (see Figure 1) is the Central Office side of
a repeaterless T1 transmission system. When used in
conjunction with an HRU-412 HiGain Remote Unit, the
system provides 1.544 Mbps transmission on two
unconditioned copper pairs over the full Carrier Serving
Area (CSA) range. The CSA includes loops which are up
to 12,000 feet of AWG 24 or 9,000 feet of AWG 26 wire,
including bridged taps. The HiGain system uses HDSL
(High bit rate Digital Subscriber Line) transmission
technology as recommended by Bellcore TA-TSY-001210.
HiGain complies with TR-TSY-000063 (Network
Equipment Building System (NEBS) Generic Equipment
requirements) and TR-TSY-000499 (Transport System
Generic Requirements—TSGR) common requirements.
1.02
The HLU-431 is compatible with any mounting
that accepts 400 mechanics including the
following PairGain mountings:
•
HRE-420, Single Slot
•
HRE-422, Dual Slot
•
HRE-427, Seven Slot
•
HRE-450, Single Slot Outdoor
•
HRE-454, Four Slot Outdoor
1.03
Revision History of this practice.
Revision 01—October 28, 1996
a) Initial release
1.04
HLU-431, List 1D features:
•
Selectable DS-1 pre-equalizer
•
130 to 200 Vdc HDSL line power for doubler
and HRU-412
•
Optional bipolar (
±
65 or
±
100 Vdc) or
unipolar (-130 or -200 Vdc) HDSL line power
voltage via switch S2
•
Front panel HDSL S/N margin display
•
Compatible with any 400 mechanic shelf
•
Selectable loopback activation codes
•
RS-232 maintenance port
•
Shelf Management interface
•
Non-volatile front panel operator setup
•
Front panel DS1 splitting and bridge access
•
Lightning and power cross protection on HDSL
interfaces
•
784 kbps full duplex 2B1Q HDSL transmission
on two pairs
•
Front panel status indicating LED
•
On / Off front panel display power cycling
•
DS1 LOS detector (125 consecutive zeros)
•
Margin threshold alarm
•
HDSL AIS and Smart-Jack AIS options
•
Easy return to factory default user settings
•
Circuit ID option
•
Low power consumption
2. HIGAIN SYSTEM APPLICATIONS
2.01
The HiGain system provides a cost-effective,
easy-to-deploy method for delivering T1 High
Capacity Digital Service (HCDS) over metallic pairs. The
fiber-like quality service is deployed over two
unconditioned, non-loaded copper pairs. Conventional in-
line T1 repeaters are not required. Cable pair
conditioning, pair separation and bridged tap removal are
not required.
2.02
The general guidelines require that each loop
have less than 35 dB of loss at 196 kHz, with 135
ohms driving and terminating impedances.
2.03
Table 1 (below) provides a guide for the loss of
various cable gauges at 196 kHz and 135 ohms.
The table applies to the HDSL cable pairs between the
HLU and HRU. Add 3 dB for each bridged tap and 1 dB
for each gauge change.
TABLE 1. HDSL LOSS OVER CABLES
Cable Gauge
Loss at 196 kHz
(dB/kft)
Ohms per kft
26/0.4mm
3.88
83
24/0.51mm
2.84
52
22/0.61mm
2.18
32
19/0.91mm
1.54
16
2.04
The HiGain system operates with any number of
other T1, POTS, Digital Data Service (DDS), or
other HiGain systems sharing the same cable binder group.
HiGain systems can be used with customers requiring DS1
service on a temporary or permanent basis. The HiGain
system also provides a means of quickly deploying service
in advance of fiber-optic transmission systems. With the
HiGain system, service can be provided within hours.
Fiber optic systems can be installed at a leisurely pace and
cut over from the installed HiGain system when
convenient to do so. The installed HiGain system can then
be easily removed and utilized elsewhere
.
