Section 150-611-100
Revision 02
Page 2
A. PRODUCT OVERVIEW
1. DESCRIPTION AND FEATURES
1.01
PairGain’s HiGain-2 Line Unit Model HLU-
611 Issue 1, List 1 (Figure 1), is the Central
Office side of a single pair repeaterless T1
transmission system. When used in conjunction
with an HRU-612 HiGain-2 Remote Unit, the system
provides 1.544 Mbps transmission on one
unconditioned copper pair over the cable ranges
shown in Table 1. The HiGain-2 system uses
VHDSL (Very High-bit-rate Digital Subscriber Line)
transmission technology. HiGain-2 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
Revision History of this practice.
Release 02 — September 7, 1995
a) Revised format.
1.03
HLU-611, List 1 features:
•
Selectable DSX-1 Pre-equalizer
•
-170 Vdc Line Power for HRU-612
•
Front Panel VHDSL S/N Margin Display
•
Selectable Loopback activation codes
•
RS-232 maintenance port
•
Non-volatile front-panel operator setup
•
Front Panel DS1 splitting and bridge
access
•
Lightning and power cross-protection on
VHDSL interfaces
•
1.568 Mbps full-duplex 2B1Q VHDSL
Transmission on a single pair
•
Front panel status indicating LED
•
On/Off front-panel display power cycling
•
DS1 LOS detector (125 consecutive
zeros)
•
Margin threshold alarm
•
Smart-Jack AIS option
•
Easy return-to-factory-default user
settings
•
Circuit ID option
2. APPLICATIONS
2.01
HiGain-2 provides a cost-effective, easy-
to-
deploy method for delivering T1 High
Capacity Digital Service (HCDS) over one metallic
pair. The fiber-like quality service is deployed over
one unconditioned, non-loaded copper pair.
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 on which the range
deployment rules in Table 1 are based
require that each HiGain-2 loop has less than 38 dB
of loss at the 2B1Q line rate of 392 kHz, with 135
ohm driving and terminating impedances.
Adherence to this rule will result in an operating
margin of at least 6 dB. The HiGain-2 system
operates with any number of other T1, POTS, Digital
Data Service (DDS) or other HiGain-2 Systems
sharing the same cable binder group. HiGain-2
systems can be used with customers requiring DS1
service on a temporary or permanent basis.
HiGain-2 also provides a means of quickly deploying
service in advance of fiber-optic transmission
systems. With HiGain-2, service can be provided
within hours. Fiber optic systems can be installed at
a leisurely pace and cut-over from HiGain-2 when
convenient to do so. The HiGain-2 system can then
be easily removed and utilized elsewhere.
TABLE 1. HIGAIN-1 VHDSL LOOP LIMITS
Cable Gauge
Loss at 392
kHz dB/kft
Ohms per kft
Maximum Loop For
35 dB Loss
Ohms at Maximum
Loop Length
26/0.4 mm
4.97
83.3
7 kft / 2.13 km
583
24/051 mm
3.87
51.9
9 kft / 2.74 km
467
22/0.61 mm
3.01
32.4
12 kft / 3.66 km
389
19/0.91 mm
2.17
16.1
16 kft / 4.87 km
258
