Tài liệu Extending DS3/STS-1 Signals to the Demarc and Beyond ppt

case study
Situation
For a major service provider in Canada providing services both as an ILEC and CLEC, DS1 remains a
viable business—not a growth business, but one with a large number of circuits and operating effi-
ciency that helps DS1s remain profitable. Recently, however, demand for DS3 services both to and
beyond the demarc has become a more common service request. For this service provider, finding
solutions for these applications was not the challenge. The challenge was to deploy extended-reach
DS3 solutions today that would not threaten operating efficiency and network reliability as the
number of DS3 circuits in the network grows.
Solution
The service provider’s standards committee selected ADC’s Extend
™
Optical/Electrical Line Extender
solution for applications that require DS3/STS-1 signals over distances up to 15 km (9.375 mi) without
use of repeaters. Where the 900 foot distance limitation prohibits use of copper, the predominant
uses of the Extend solution are as follows: extending DS3 service beyond the demarc within buildings
or multiple buildings in a campus; and delivering DS3 from the central office to the customer site.
The Extend O/E Line Extender is a carrier-class system that includes a rack-mount chassis for up to
24 DS3/STS-1 modules as well as a wall mount chassis that holds one or two DS3/STS-1 module.
Both the rack-mount and wall mount chassis use the same bidirectional, plug-in style DS3/STS-1
module. A/B power feeds support redundant power and full alarm capability. Each module also pro-
vides status LEDs for power, transmit failure and receive loss-of-signal for each channel.
Operationally, the Extend system is a simple product — a factor that greatly appealed to the service
provider in solving distance issues associated with DS3 services. On one end of a circuit, the
DS3/STS-1 module converts an electrical signal into an optical signal for transport over singlemode
fiber. At the far end of the circuit, the DS3/STS-1 module converts the optical signal back to electrical.
One local and one remote module together serve as a dual regenerator to extend the distance of a
single DS3/STS-1 circuit.
Extending DS3/STS-1 Signals
to the Demarc and Beyond
Rack-Mounted Chassis

Wall-Mount Chassis
with extension brackets
2
Selection Criteria
When compared to competitive products, the Extend O/E Line Extender excelled in several aspects.
First, it was apparent that ADC offered a superior system for cable management. Copper and fiber
cables are clearly separated — DS3/STS-1 input and output terminations are on the rear of modules;
optical transmit and receive connectors are located on the front. In addition, the minimal-profile wall
mount unit includes an integrated fiber storage spool that prevents haphazard looping and coiling of
fiber cables in remote locations that shorten service life of fibers and disrupt service. The integrated
fiber storage also adds a more professional appearance for such remote locations as closets, base-
ments, CEVs, and other tight spaces.
The rack-mount chassis includes cable support bars on the rear for coax cables and radius limiters on
the front for protection of fibers terminated at SC connectors. With installation of vertical cable guides
on the front of the rack, guides that use no rack space, optical fibers can be safely routed to splice
decks and storage trays.
The second factor that helped gain approval of the Extend O/E Line Extender was density of the rack
mount chassis, a feature that affords greater flexibility in providing service to customers. The Extend
chassis supports 24 plug-in modules and, with advanced heat dissipation features, does not require
use of valuable rack space for such external devices as cooling fans and air filters to maintain proper
operating temperature. Reliance on fans to cool DS3 modules was deemed too risky for such high-
value circuits. In addition, integrated cable management features of the Extend O/E Line Extender use
no additional rack space and present a minimal rack profile that does not impede closing of cabinet
doors.
Finally, field trials confirmed that the Extend O/E Line Extender was simple to install and configure.
With no training or complex software administration required, the operations department was able to
reduce installation time and ease turn-up of service.
Conclusion
With ADC fiber frames already deployed across the network, the service provider was already well
aware that proper management of fiber cables breeds reliability and operational efficiency into the net-

work. The features that characterize all ADC fiber solutions — including high density, superior cable
management, modularity, and ease of service turn-up — carried over to the Extend O/E Line Extender.
The ADC solution was the preferred product for building reliability and operational efficiency into the
growing inventory of DS3 circuits.
3
Network
Element
DSX
O/E
Line Extender
Singlemode Fiber Optic Cable
up to 15 Kilometers
(9.375 miles)
Network
Element
DSX
O/E
Line Extender
Central Office or High-Rise
Business Office Building
E3/DS3/STS-1 Optical Line Extender Used in Multi-floor
Central Office and Collocation Environments
Network
Element
DSX
O/E
Line Extender
Singlemode Fiber Optic Cable
up to 15 Kilometers
(9.375 miles)

Network
Element
O/E
Line Extender
Centralized Campus Headquarters
Remote Building
Remote Building
Remote Building
E3/DS3/STS-1 Optical Line Extender Used in Building Local
Exchange Carrier (BLEC) and Campus Environments
ADC Telecommunications, Inc., P.O. Box 1101, Minneapolis, Minnesota USA 55440-1101
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reserves the right to change specifications without prior notice. At any time, you may verify product specifications by contacting our headquarters
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1274852 10/03 Original © 2003 ADC Telecommunications, Inc. All Rights Reserved
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