Section 150-611-103
Revision 01
Page 2
A. PRODUCT OVERVIEW
1. DESCRIPTION AND FEATURES
1.01
PairGain’s HiGain-2 Line Unit Model HLU-
611 Issue 1, List 3 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 Mb/s transmission on 1
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.
Revision 01 — July 14, 1995
a) Initial release.
1.03
HLU-611, List 3 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 & brdg access
•
Lightning and power cross protection on
VHDSL interfaces
•
1568 kb/s full-duplex 2B1Q VHDSL
Transmission on 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 1 metallic pair.
The fiber-like quality service is deployed over 1
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 have less than 35
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-2 VHDSL LOOP LIMITS
Cable Gauge
Loss @ 392
kHz dB/kft
Ohms per kft
Maximum Loop For
35 dB Loss
Ohms @ Maximum
Loop Length
26/0.4 mm
4.97
83.3
7.0 kft / 2.13 km
583
24/051mm
3.87
51.9
9 kft / 2.74 km
467
22/0.61mm
3.01
32.4
12 kft / 3.66 km
389
19/0.91mm
2.17
16.1
16 kft / 4.87 km
258
