On 10/11/19 9:43 PM, Matt Hoppes wrote:
And this is why the distributed nature of small node’s is detrimental in an
extended power outage.
There is no practical way to back them up with power for an extended period of
time.
How distributed is the power on a typical HFC system in practice? I'm
sure I'm missing some of them, but having walked out most of a small-ish
(~2000 residences) city recently for a FTTx deployment, I think I only
saw 2-3 power nodes on Comcast's plant. There were several times as
many fiber-coax nodes being line-powered off the coax plant though still
surprisingly few (the plant is ancient and hasn't seen a lot of fiber
overbuild).
That's comparable to how many powered RTUs the LEC had in town and many
fewer utility-powered field nodes than would have been present if it had
been in AT&T Lightspeed territory.
Now, I have no idea what the backup line power is in practice on that
Comcast plant. I know that Bright House/Spectrum, in an another area
I've supported, has very little backup on many residential-only parts of
their plant. I've observed that they have, in practice, maybe 15-30
minutes of hold-up before DOCSIS nodes start dropping.
--
Brandon Martin
