Steven R. & Larry Brew,
Great write-up Steven! Thanks for helping Larry out....
Hope you don't mind if I make one small correction.
As you may know the bandwidth limitations are not caused from the transmission lines themselves, but in fact are limited by filters at the edge of the voice network, as well as loss associated with splicing.
Actually Bandwidth limitation is caused by the transmission lines, The size of the pipe and distance, the copper twisted pair having 1.1 Mhz, of which we only utilize 4Khz for voice.
Most Loading Coils are at 18,000ft from the CO which were put in place to boost the voice signal for extended distances.
Apprx 80% of the POTS in the U.S. is capable of ADSL transmission, as surveys have shown 80% have Loading Coils at 18,000ft.
60% of the U.S is within 12,000ft of the Company Office
A problem I seem to have trouble resolving with ADSL is all that
copper. Maybe you or another can put it to rest. Copper, being a
crude transmission line seems to me that it would offer significant
Xl and resistive losses during transmission. Won't the inductive
properties of these lines offer a problem over longer distances at higher frequencies?
Transmission lines have long since left these aged memory banks. :-)
Larry
Larry,
I thought you might like to know how the Magic works.
This may help if it's not to technical.
Message 555777
And for VDSL
Message 2274306
And from the Man Himself or A Word from our Sponsor!
internettelephony.com
techweb.com
internettelephony.com
Best Regards,
JW@KSC |
