Section 150-219-100-02
December 22, 1997
Page 2
HDU-217/219 and
HCC-239 List
1
The HDU-217 and HDU-219 HiGain doubler units (HDUs) extend the
delivery of fractional T1 High-Capacity Digital Service (HCDS) to
customers over metallic cable pairs. The HDUs are installed between
a HLU-D41 List 2D (HiGain line unit) and a HRU-512 (HiGain
remote unit).
The HDU-217 and HDU-219 allow 784 Kbps transmission over twice
the normal Carrier Serving Area (CSA) range to 24,000 feet
(7.315 km) of 24 AWG or 18,000 feet (5.486 km) of 26 AWG copper
loops. Two doubler units can triple the CSA range to 36,000 feet
(10.97 km) of 24 AWG loops or to 27,000 feet (8.22 km) of 26 AWG
loops.
The HCC-239 (HiGain Cut-through Card) is provided with the
HDU-219. The HDU-219 mounts into two adjacent slots of a
standard 239 mini-T1 repeater apparatus case and blocks one slot.
The HCC-239 allows pair cut-through on the blocked repeater slot.
The HDU-217 doubler units occupy one slot of the original DDS or
ISDN repeater apparatus case—these slots are about twice the width
of a 239 T1 repeater. All HiGain modules comply with the applicable
requirements of Network Equipment Building System (NEBS)
Generic Equipment requirements TR-TSY-000063 and Transport
System Generic Requirements TSGR TR-TSY-000499.
About the Mini Doubler
HiGain uses PairGain’s Two-Binary, One-Quaternary (2B1Q) High-
bit-rate Digital Subscriber Line (HDSL) transceiver systems to
establish a full-duplex, 784 kbps data channel between the line units
and the remote units. Each HDU-217 and HDU-219 increases the
maximum range of a new doubler circuit by approximately 12,000
feet (3.66 km) for 24 AWG cable or 9,000 feet (2.74 km) for 26 AWG
cable.
A block diagram of the HDU-217 and HDU-219 with pinouts is
shown in Figure 2. The HDU-217 and HDU-219 power supplies use
the 200 Vdc power feed voltage received on the HDSL pair to
produce the +5 Vdc and –5 Vdc required by the HDU-217 and
HDU-219 electronics. The power feed continues through the HDSL
output pair to a second doubler or to the remote HRU-512.
