PairGain PRL-770, Manual

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950-770-100 March 14, 1997 Revision 01
PG-Plus PRL-770 PairGain Engineering-Plant Series Page 1
A. PRODUCT OVERVIEW
1. Description and Features
1.1
This practice describes the PairGain
®
PG-Plus
™ PRL-770 List 1A, a Remote Terminal (RT)
enclosure that houses one Remote Line Unit (RLU) and provides interfaces for up to four Plain Old
Telephone Service (POTS) subscribers.
1.2 PG-Plus Systems.
A PairGain PG-Plus system provides bi-directional transport of multiple DS0s
over a single, unconditioned wire pair using High-bit-rate Digital Subscriber Line (HDSL)
technology. Using existing cable, PG-Plus provides for higher bandwidth needs of residential and
business customers by providing multiple POTS interfaces on a single HDSL twisted-pair wire.
Figure 1 shows a minimally configured PairGain PG-Plus system that consists of:
•
One Central Office Terminal (COT) shelf
•
One Central Office Line Unit (COLU)
•
One RLU (housed in an RT)
Figure 1. Typical PG-Plus System
Each COLU housed in a COT shelf interfaces with a corresponding RT. Using one pair of 24 gauge
wire, the RT may be located up to 21.7 kft from the COT. POTS or digital lines from a Central
Office (CO) switching system connect to the COT and are sent via the COLU and the HDSL wire
pair to an RT. As an example, a 23" COT shelf can interface with 16 different PRL-770 RTs
providing four POTS lines each, for a total of 64 subscriber lines. The COT operates on standard -48
V dc CO battery and supplies power to the RT, eliminating the need and expense of providing local
power. A PG-Plus system with HDSL transmission and line powered RTs therefore results in fast,
cost-effective solutions to POTS deployment over minimal copper facilities.
1.3 HDSL. PairGain HDSL technology provides the equivalent of 256 kbps digital transmission rate
without the need for repeaters, loop conditioning, or pair selection. The PRL-770 motherboard
terminates the HDSL line with secondary surge protection, provides power converters and
microprocessor circuitry, and synchronizes to the HDSL line rate from the COT. The PRL-770 maps
the four DS0 channels from the HDSL line to the individual subscriber circuits, and can be located
up to 31.2 kft (22 gauge wire) from the COT shelf. The PRL-770 operates at a nominal HDSL line
rate of 261.3 kbps.