Overview
150-388-125-01, Revision 01
2
September 15, 1998
HLU-388 List 2E
A
PPLICATIONS
HiGain systems provide a cost-effective, easy-to-deploy method for delivering T1 High Capacity Digital Service
(HCDS) over metallic pairs.
•
The service is deployed over two unconditioned, non-loaded copper pairs, yet it demonstrates a quality that
is competitive with fiber optics.
•
Conventional, in-line, T1 repeaters are not required.
•
Cable pair conditioning, pair separation and bridged tap removal are not required.
Each loop has no more than 35 dB of loss at 196 kHz, with driving and terminating impedances of 135
Ω
.
provides a “loss” guide for the various cable gauges at 196 kHz and 135
Ω
. The table applies to the HDSL
cable pairs between the HLU, HRU, and HDU modules. In the absence of specific insertion loss measurement
data, add 3 dB for each bridged tap and 1 dB for each cable gauge change.
In general, HiGain systems:
•
operate with any number of other T1, POTS, Digital Data Service (DDS) or other HiGain systems sharing the
same cable binder group
•
can be used with customers requiring DS1 service on a temporary or permanent basis
•
provide a means of quickly deploying service in advance of fiber-optic transmission systems
With a HiGain system, service can be provided within hours. Fiber-optic systems can be installed incrementally
and cut-over from the installed HiGain system when convenient to do so.
Applications Without HiGain Doublers
For applications without doublers, the HLU-388 is directly connected to the HRU by the two HDSL cable pairs.
The HLU-388 is compatible with all HiGain HRUs.
Applications With HiGain Doublers
For doubler applications, one or two doublers may be used in the HDSL loops between the HLU and HRU. When
using two doublers, the HRU must be locally powered.
Table 1.
HDSL Loss Over Cables
Cable Gauge (AWG/mm)
Loop Loss at
196 kHz (dB/kft)
Loop Resistance
(
Ω
per kft)
26 / 0.4
3.88
83
24 / 0.51
2.84
52
22 / 0.61
2.18
32
19 / 0.91
1.54
16
For compatibility guidelines on mixing newer doublers with older HRU and HLU models, refer
to
“Doubler Deployment” on page 54
.
