digital converter box -- surprising performance

Robert S Chase
Wed Jun 18 13:37:25 EDT 2008

Okay, as radio people we need to know all about telco connections since at 
one time before the advent of microwave links, etc, this was all we had to 
do remotes. I can remember having to bridge into a pay phone pair with our 
emergency backup pair of capacitors to send a remote when telco failed to 
make the central office connections on the other pair back to the studio. 
(They were using yellow and black pair on the pay phone to get to the 
central office, sent someone out and installed it at the site, then failed 
to make the patch at the CO on time. (shift change) Since the pair in the 
box I was supposed to use didn't work I had the studio call me on the pay 
phone and used the other pair, red and green which was sitting right there 
also. Think we bridged in there also so we wouldn't have the beep tone.  CO 
wasn't too impressed with my output levels when they looked at it but as I 
told them "what's a guy to do when they fall down!"  and they accepted the 
situation grudgingly. Don't remember if we got a refund on the remote charge 
but they didn't respond to our calls for help until the remote was nearly 
over. <grin>).

So back to the query, when they pull the fiber out to the subscriber loop, 
will they leave copper in place for all those who keep their POTS? Will it 
be on the existing cable pairs or will they do a conversion process at the 
pole or some local distribution point? I understand that copper cables have 
a pair for each subscriber from the central office and then they go through 
junction box near the subscriber where they branch off. (correct me if I am 
wrong) They are going to have to do a similar thing with fiber won't they or 
will there be a decoder at the network interface at each subscriber? Won't 
that have to be powered anyway? And if that is so, why not simply run a dc 
pair either in the fiber cable, wrapped with it, or along side it to provide 
the dc? Does anybody know a good URL that can explain old POTS and new fiber 
service (plain old vanilla as well as FIOS or other?)

Bob Chase

> Perhaps because they will still have to provide power over copper at the
> subscriber's premises.  Now, instead of relying on just the central
> office big bank o'batteries,  power must be derived locally to the
> subscriber.  Necessitating either another set of batteries or when local
> power dumps, the subscriber is out of luck.  Many people rely on POTS
> for a reliable, low-tech connection between the CO and their alarm 
> systems.

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