this extra step can save a cable system
time, labor, and money as a result of
on-site detection/repair. In addition,
undetected, on-going ingress and
egress leakage contribute to the com-
bined interference that already affects
the quality of service provided to the
customer. Unless the field technician
adopts a standard ingress prevention
procedure, the quality of service provid-
ed to the advanced cable system sub-
scriber would always be in question.
With the growing demand for digital
carrier transmissions, the need to pre-
vent all potential sources of ingress
leakage into the cable system is critical.
Eliminating egress sources and reduc-
ing the potential for ingress into the
cable system will not be a quick fix.
Egress and ingress leakage sources
exist everywhere and will remain at vari-
ous frequency levels. The FCC requires
that leakage sources with a minimum of
20 µV/m must be repaired for the cable
system to remain compliant. If a cable
system’s goal is to reduce egress and
ingress levels in their overall cable sys-
tem, a minimum acceptable level of
egress and ingress leakage should be
suggested to the technician by their
cable system procedures.
Ingress is considered to be one of the
biggest obstacles in deploying inter-
active services over the return path of
the cable network. Most ingress (up to
95% of all ingress) originates in the
home and distribution network. Each
home's ingress is combined to accu-
mulate the total ingress noise level of
the entire network of homes serviced
by a node. Therefore, it's important
to keep each individual home under a
certain ingress threshold. You can get
the total ingress signature of a single
home at the tap.
(for more detailed infor-
mation refer to the ACTERNA Wallchart: RF
Signal Leakage “Find & Fix” Guide)
During in-home installation or inspec-
tions, the minimum requirements of the
cable technician should include:
• Follow your cable system’s stan-
dard on minimum acceptable lev-
els of egress and ingress.
• Always use and check for good stan-
dard cable installation practices.
• After cable installation/inspection,
walk through the subscriber’s resi-
dence to check for egress leakage
sources
• Complete all egress testing first
(In-home testing is preferred to
testing outside the home).
• Complete an ingress test at the
ground block
4-13
For the first year, I got to run
behind the truck...
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