Triple-Play Service Deployment

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Chapter 3: Deploying and Troubleshooting Fiber Networks
Stage 3: PON Frame Installation and Connection
After feeder and distribution cable construction, frame installation
can be performed. For PONs, several frame types are installed.The
first frame is the fiber distribution hub (FDH), housed in an outside
cabinet which also contains the splitters used in the network.
While other splitter combinations may be used, FTTH networks
frequently employ a single FDH with a 1x32 splitter structure or
multiple FDHs with 1x8 and 1x4 cascaded splitters. At the FDH all
fibers coming from the CO are spliced to the splitters.
An OTDR measurement, performed from the CO, is recommended
to verify splice quality. All connectors from the splitter output
should be placed in the parking lot to store the pigtails in a
separate path to reduce fiber congestion. All fibers going to the
distribution network are connectorized. A measurement at
1310/1550 nm is then performed from the hub to check the splice
quality.
The second frame, the access terminal, is located close to the
customer premises, and it consists of a splice enclosure located
either on a pole or in a manhole. A set of fibers (usually 4, 6, 8, or
12) coming from the cable are extracted and spliced to be
connectorized to drop cables. An OTDR measurement from the
hub is recommended to check the splice quality.
The third frame to be installed is usually the fiber distribution
frame (FDF) cabinet which is located at the CO. Like the other
frames, the fiber is spliced to a pigtail in order to be connected to
the patch panel. An OTDR measurement is then performed from
the CO to check the splice quality. For large networks, other FDFs
may be located on the feeder in order to distribute the different
cables. The same process applies to those frames.