GUADALUPE VALLEY DEPLOYS FIBER TO THE PREMISE

INTRODUCTION
Guadalupe Valley Telecommunications Cooperative, Inc. (GVTC) was formed in
1951 and today is the largest telephone cooperative in the state of Texas.
Spanning 2,000 square miles in eleven counties to the north and east of San
Antonio, GVTC serves over 30,000 customers with more than 43,000 access lines.
The company is a local exchange carrier, operates its own long distance company
and cable television subsidiary, and offers high speed Internet access as well as
security systems and monitoring for medical and alarm applications.
All GVTC subscribers are also members and owners of the cooperative, making
service and quality more important than with public companies without such firm
ties to the communities they serve. This unwavering commitment to service is an
important differentiator as GVTC battles a large MSO for subscribers. In addition,
the non-profit co-op must operate efficiently because members are used to
receiving the annual distribution of profits each June.
Creating an efficient, high performance infrastructure that can deliver a low cost
of ownership for many years to come was one of the main reasons GVTC decided
to implement fiber-to-the-premise (FTTP) for new construction. Riding the steady
building boom in their serving areas, GVTC has laid fiber to over 2,500 homes in
2004 and has started work on the fiber infrastructure on new subdivisions for over
5,000 housing units. In existing subdivisions that are copper-fed, the long-range
plan is to implement FTTP when copper is retired.
GUADALUPE VALLEY DEPLOYS
FIBER TO THE PREMISE
CASE STUDY
CENTRALIZED SPLITTERS REDUCE COSTS
Early in the planning phases for its FTTP projects, GVTC aligned itself with a centralized splitter
architecture in the PON (passive optical network). “There were at least a couple of different ways to
take fiber from our switching equipment to the customer. We found centralizing splitters in one location
to be the most efficient and cost effective design,” said Randy Lefler, engineering supervisor who
manages GVTC’s three staff design engineers.
To support the design, GVTC has deployed ADC’s OmniReach™ Fiber Distribution Hub (FDH) for

centralization of splitters in the field. Instead of deploying splitters at a hub as well as at access terminals
closer to premises, GVTC equipped each FDH with 1x32 splitters to mirror port capacity of optical line
terminal (OLT) cards in their central office. Ensuring easy, lower-cost technology upgrades in the future
was one important reason for centralizing splitters.
“By centralizing splitters in one location, it allows us to do simple upgrades and keep up to changes in
technology,” said Lefler. “If I had splitters in different locations in the field, any upgrades would be
massive cabling projects. Using the (ADC) PON cabinet, I only have to upgrade one single point to keep
up with the technology.”
Yet there were also immediate and near-term savings and efficiencies realized by GVTC due to the
unique design of the OmniReach FDH. Because of the way GVTC was taking distribution fiber from the
field, having the cabinet stubbed-out at the ADC factory helped splicers work more efficiently. The
design cut fiber termination time in half and resulted in better splices, according to Lefler.
In addition, the OmniReach “parking lot” feature that allows pre-terminated splitter output fibers to be
stored until needed for service activation allows service turn-up by mating connectors in the distribution
field, work that can be performed more quickly and by a technician rather than by a highly skilled
splicer. This feature cuts the time required for service activation, according to Lefler.
CASE STUDY
Randy Lefler of GVTC demontrates the procedure for service turn-up in
the field using ADC's OmniReach FDH (Fiber Distribution Hub). He moves
a preterminated splitter output jumper from the parking lot at the
bottom of the cabinet and mates it with a connector in the distribution
field that corresponds with the residence. Reducing the time required for
service activation was just one reason why GVTC deployed a passive
optical network (PON) with splitters centralized in the FDH.
FIBER DISTRIBUTION HUB DESIGNED FOR GVTC
GVTC continues to order OmniReach Fiber Distribution Hubs because ADC has proven enormously
responsive to the company’s changing requirements.
“I have found ADC easy to work with and very responsive,” said Lefler. “They (ADC) have provided
everything we have asked for and made adjustments to fit our operation,” he said.
For example, the distribution field for the 360-fiber-count FDH houses five separate fiber panels. Each

panel supports 72 fiber terminations. However, labels on the doors were numbered one through 72,
one through 72, and so on, to match individual distribution panels. This was a confusing labeling
scheme that was going to cause problems, according to Lefler. By request of GVTC, ADC immediately
changed the numbering scheme on labels for GVTC’s 360-count FDH cabinet to 1 through 360. The
same change was made to 576-count FDH cabinets deployed by GVTC.
GVTC also wanted factory-terminated connectors on the incoming fibers on splitters so that adding
another splitter to a FDH cabinet could be done without sending out a splice truck. ADC made that
change for GVTC, too.
“The labeling change and having connectors on incoming (splitter) fibers were not trivial changes for us.
These changes save time, eliminate confusion, and help us improve service for our member-
subscribers,” said Lefler.
GVTC and countless other service providers have benefited over the years from ADC’s highly flexible
manufacturing processes. “Our customers have long valued our commitment to quality on our
manufacturing floor,” said Tom Kampf, director of product management. “They also know our flexibility
to quickly make changes to standard products to better meet the needs of their operation. By providing
FDH cabinets that meet GVTC’s unique operational requirements, we become more than just a
manufacturer. We become their partner in efficiency and profitability,” said Kampf.
CASE STUDY
An ADC Fiber Distribution Hub (FDH) for a GVTC site is
shown mounted on the templated side of the
fiberglass/concrete composite below ground handhole.
Because GVTC orders stubbed cabinets, the 100 feet of
fiber cable stub is uncoiled to reach the splice trailer for
a proper splicing environment. Once the splices are
complete, the fiber stub cable and splice case is safely
stored in the handhole.
MAKING THE CHOICE BETWEEN CASCADING AND CENTRALIZED SPLITTERS IN THE PON
Once the decision is made to utilize PON architecture in FTTP deployments, the two basic splitter
configurations are centralized and cascaded.
With centralized splitters, each 1x32 splitter in the outside plant enclosure is connected to an optical line

terminal (OLT) card in the headend, CO or data center. It is important to note that today’s OLTs support up
to 32 subscribers. Within the OSP enclosure, each of the 32 split fibers are routed from the splitter to a
distribution panel where each port appearance represents a home or business.
In a cascaded splitter arrangement, 1x4 or 1x8 splitters reside in the OSP enclosure and are connected
directly to an OLT in the headend, CO or data center. Each of the four or eight fibers from the splitter are
routed to an access terminal near the premise where either 1x4 or 1x8 splitters reside.
ADC can provide guidance on the appropriate splitter configuration for your project. Considerations such
as conservation of capital, craft efficiency, and long-term cost of ownership are evaluated. In general, when
comparing centralized and cascaded splitter configurations, the pros and cons line-up roughly as follows:
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CASE STUDY
Cascaded Splitters
Pro
• Lower distribution cable costs.
• Better for widely scattered areas.
• Good if high take rates are quick and certain.
Con
• More OSP cabinets in neighborhoods.
• Can strand OLT capacity and waste capital.
• More expensive when electronics are
upgraded.

• Can require additional upfront capital for
OLT cards.
• Higher overall loss due to multiple splitters.
• Difficult to troubleshoot through multiple
splitters.
• Prone to higher network outage rate.
Centralized Splitters
Pro
• Best for OLT port utilization.
• Best for lower upfront OLT capital costs.
• Easier and less costly when electronics
are upgraded.
• Fewer cabinets in neighborhoods.
• Better for limited take rate builds.
• Provides centralized troubleshooting point.
• Lower overall splitter loss.
Con
• More investment in distribution fiber.
• Not ideal for widely scattered areas.