The Lost 20%: A Hidden Network Cost6/27/2011 12:01 AM Eastern
Cable operators at the Cable Show in
Chicago earlier this month saw a vast array of technology
and equipment, all promising to deliver some level of financial gain, many through network-capacity upgrades
for interactive applications. But network performance
can be dramatically improved without
an upgrade — and with a significant payback
— through what we call “The Lost 20%.”
The Lost 20% are disconnected set-tops that
can amount to a small fortune in network overhead
and costs, yet can boost an operator’s revenue
if brought under control. Compare the
number of set-tops in your inventory to the number
of paying set-tops. On most systems, we see
a 20% difference. The details show that some
are inventory, but most are unrecovered disconnects.
You may have written most of these
off . But they’re still out there, costing you bandwidth
An inactive set-top continues to affect your network because
it’s usually still defined in your addressability system.
It’s being polled during weekly chronic nonresponder cycles,
over multiple downstreams, in a futile attempt to find
it. On a system with 500,000 set-tops, that 20% represents
100,000 units, and we’ve seen chronic poll cycles last more
than five days. So much for quick overnight polls.
And what about an operator’s on-account set-tops? Many
have a last-reported transmit level at the top of the allowed
range. For a chronic or power-level poll, these units will generate
several messages, starting at the lowest level, and increase
their transmit power until they’re acknowledged
— or ultimately give up. At the margins, these set-tops may
be generating multiple retries in their ordinary communication
for video on demand, switched digital video, pay-perview
reporting or network-address acquisition. Added up,
it’s a network cacophony most systems don’t measure.
How many set-tops can a return path
Our audits show an average of about 1,000
set-tops per return demodulator, and we see
operators building out to lower this number.
Capacity planning is a black art, with operators
wishing for some kind of analyzer to show
them what’s happening on the plant side. But
we’ve seen a system with 2,000 set-tops per
path, an excellent nonresponse rate, no perceptible
problem with VOD or capacity, and a
happy subscriber base. It’s no coincidence that
when this system disables a set-top, its polling is
turned off . Field techs are trained to check and
correct transmit-level issues whenever they enter a home,
with automated, post-call verification and reporting by tech
With the right tools and processes, the payback is clear.
Cleanups have reduced chronic non-responder poll cycles
from five days to 12 hours. When deactivation commands
are sent to each set-top, tracking results shows units coming
back to paying status after being allegedly disabled for
months — in some cases, as many as 1%. When a new account
is valued at $1,000 the first year, and you’ve avoided
some node splits by reducing unnecessary traffic, this has
a major impact on the bottom line.
R.J. Juneau is chief technology officer of Maxxian.