Triple-Play Service Deployment

126
Locating and resolving coax problems
Existing coaxial home networks present a variety of challenges.
Constructed by the home builder, the owner, or perhaps a previous
service provider, the quality and routing of the network is rarely
known. A high-quality coax installation should provide at least
30dB noise isolation to the outside world. This isolation is referred
to as noise immunity. However, these networks often contain
splitters, pinches, breaks, bad cables, un-terminated ends, bad
connections, or amplifiers—all of which may lead to network
problems and QoS issues. Proper grooming of the network to
remove and repair or replace portions of the network to meet the
triple-play service provider standards is critical to providing
reliable services.
One of the biggest impediments to installing interactive services
that utilize the existing coaxial network is determining the
configuration of the distribution network. Further, the in-home
technician must identify any potential problems with the network
before turning up service. The technician may spend valuable
hours trying to discover the network architecture manually
through process of elimination. Locating faulty or undesired
components is a tedious and lengthy process which often requires
the technician to enter attics, crawlspaces, and/or basements.
Unknown
nested splitter
RG or NID
Crawl space
Modem
Attic
HDTV
Figure 5.6 Complexities of mapping existing networks.
Chapter 5: Troubleshooting the Premises Wiring
STB
Unterminated
port in attic
Open cable end
Pinched cable