As these next-generation services de-mand higher levels of bandwidth, high-am-perage power protection becomes increas-ingly critical for network integrity.. But as ca-ble networks delve
Trang 1Net working A D V A N C E D N E T W O R K I N G T E C H N O L O G Y More power to the bottom line
Next-generation services require high-amperage power protection
By David Schomaker, Senior Product
Manager, Connectivity Business
Unit, ADC Telecommunications
Cable television has changed No
longer just a medium for delivering
television signals, it has evolved to
de-liver the most advanced multimedia services
in communications Multiple system
opera-tors (MSOs) are building and rebuilding
their networks to compete with local
telecommunication companies for
revenue-generating high-speed data and primary line
services As these next-generation services
de-mand higher levels of bandwidth,
high-am-perage power protection becomes
increas-ingly critical for network integrity
Integrating new, current-hungry,
high-speed data network elements into a cable
network can cause havoc for cable
televi-sion operators With manufacturers
incor-porating higher density electronics and
components into smaller-sized packages,
custom-configured power distribution
plat-forms are necessary to accommodate not
only the high amperages, but specific
re-quirements of various applications
A well-conceived powering platform
will save money, resources, and customers,
especially when using cable modem
ter-mination systems (CMTS), laser
transmit-ters and receivers to deliver enhanced data
and carrier-class primary line telephone
services Keeping customers happy and
reducing churn is critical for operators
And an effective power distribution
plat-form can produce immediate results
Power to the people
MSOs have traditionally used AC
pow-er at the headend, while their telephony
counterparts have used DC power But as
ca-ble networks delve into the telephony realm,
operators are powering much of their
re-vamped network with DC power to preserve
services even during power outages
Telephony is a lifeline service–subscribers de-mand immediate, always-on services When 99.999 percent service reliability is not only expected, but also required, preemptive troubleshooting is critical in maintaining customer satisfaction
Missing the sec-ond half of a fa-vorite television program may be an-noying for cable viewers, but failing
to complete a 911 call can have grave consequences for telephony subscri-bers That is why ca-ble operators now take extra precau-tions to protect and distribute power in their networks by installing high-am-perage protection platforms
In today’s busi-ness environment, every decision af-fects the bottom line Cable operators must make prudent, proactive decisions
The impact of power protection and dis-tribution platforms on network integrity can no longer be overlooked A reliable platform minimizes operational costs, pro-tects vital, revenue-generating equipment, and ensures the delivery of advanced mul-timedia services to customers
Pump up the amperage
Today’s critical cable network elements re-quire power Lots of it Manufacturers are packaging more complex components and electronics into smaller network elements
Asked to do more, do it in less space, and do
it more efficiently, operators are
incorporat-ing high-amperage power distribution plat-forms into the headend to preserve rack space, slow network expansion and optimize the functionality of high-density equipment Cable telephony is potentially the most lucrative piece in the converged triple play
of data, voice and video services A crit-ical element to its ul-timate success re-sides in the perfor-mance of CMTS units Designed to handle the opera-tional, management and service demands
of today’s competi-tive cable television marketplace, this technology serves both high-speed data and telephony traf-fic It is a perfect ex-ample of a high-den-sity network element designed to meet to-day’s high-band-width requirements Cable operators can increase their profitability by increas-ing the number of throughput ports in a CMTS Many of the newest, most effective CMTS units have twice the number of ports from previous architectures This technological breakthrough has also dou-bled the amount of power required Whether it’s the electronics, components or the fans required to cool it, contemporary CMTS units require a high-amperage pro-tection and distribution platform to en-sure continuous revenue growth
Distributed power
Cable television operators are beginning
to deploy cable network solutions com-prised of several technologies incorporated
Figure 1: Varying amp equipment.
Trang 2into a single rack to accelerate the delivery
of high-value broadband services This trend
has led to a greater reliance on flexible
pow-er distribution platforms Most of these rack
solutions feature CMTS units and RF
trans-mitters and receivers that require amperage
protection Even though routers,
demarca-tion points, lasers, amplifiers and transport
equipment may not be included in these
cable network solution racks, they still
re-quire DC power distribution and protection
And all the network elements feature
dis-parate amperage allotments
Some applications now require more than
70 amps of distributed DC current per
net-work element Previously, a battery
distribu-tion fuse bay (BDFB) may have provided
this amperage directly to each network
ele-ment in the rack This method wastes
pre-cious BDFB positions Each run from the
BDFB creates another expense for
opera-tors Running one cable from the BDFB to a
power distribution panel can save expenses
The best power distribution platforms
now provide up to 200 amps in a single rack
unit and include various output amperage
ca-pabilities to ensure each network element is
fed sufficient current–at a cost commensurate
with the requirements Most installations
re-quire both high and low amperage Effective
power distribution platforms deliver various
amperages to accommodate the specific
re-quirements of each network element, helping
improve network integrity and efficiency
Reliable power
Power is often treated as a commodity, at least until disaster strikes A power outage can be devastating to a cable television op-erator Without power, key network ele-ments become inoperable and service is jeopardized Subscribers are quick to jump
to another provider if they are dissatisfied with the quality and reliability of their current service Cable television operators are sub-sequently revamping existing headends and hubs with DC-powered functionality in an at-tempt to shore up and maintain reliability
Each cable network is unique, but the most reliable and cost-effective networks use combinations of AC and DC power to
ensure compatibility with specific elements and applications AC powers television programming hardware Enhanced data and telephony elements tend to rely on
DC power There is no hard-and-fast rule–operators often go with the method that they are most comfortable with or the one that delivers the best-perceived
val-ue DC power costs more to deploy, but it better accommodates the specific require-ments of advanced services such as cable telephony more effectively
Many cable operators regard DC
pow-er as an investment that minimizes failure points and speeds repair time The more time it takes to repair, upgrade and install equipment, the more profit margins are eroded Personnel costs skyrocket and
cus-tomer satisfaction wanes Designed to
lim-it failure points and improve redundancy,
a DC-powered network helps foster con-tinuous service, resulting in lowered oper-ational costs and increased revenue
Heading to DC
DC power begins the same way AC does, as an alternating current from a gen-erator It is then converted to DC at the headend through the use of rectifiers Eventually DC power is fed to the
prima-ry power panel, which in turn feeds the bat-tery distribution fuse bay (BDFB) If ex-ternal power were to fail, the batteries con-tinue to power network elements without
a service lapse The rectifiers also keep the battery banks charged in case of an AC power failure at the initial feed destina-tion This built-in redundancy enables net-work elements connected to multiple feeds
to preserve service integrity, even if a par-ticular power source fails
A higher power
The cable television industry is boom-ing And as it ramps up to meet subscriber demands, its service offering is becoming more complex, requiring increasing amounts of power Advanced services, new technological innovations and revenue-generating opportunities are readily avail-able But all can be lost with the flick of a switch unless a reliable and flexible power distribution platform protects the vital ca-ble equipment in the headend
With many CMTS units featuring twice the throughput capacity of previous models; laser, amplifier, transport and routing equip-ment transitioning to DC power; and cable television networks now delivering lifeline telephony services–absolute reliability is critical Revenue-generating equipment must
be powered and protected to maintain and grow continuous revenue streams Subscribers demand always-on service Successful cable operators provide it ■
Figure 2: Power distribution scenarios.
E-mail: David_Schomaker@adc.com
Reprinted from CED, June 2002 by Reprint Services.
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