7 Oct
2009
7 Oct
'09
1:46 p.m.
joel jaeggli expunged (joelja@bogus.com):
ADSL systems will retrain to a lower rate as line conditions (SNR) change for the worse. The attentuation characteristics of a given pair will change of time due to a number of factor, including but not certainly limited to physical wear, moisture invasion, localized source of interference, sunspot activity etc.
Are dsl plants subject to localized environmental conditions? Absolutely.
I could be convinced that extremem heat could change a cables velocity factor, but that should only result in slight changes in phase, which I guess would result in a higher BER. Oh, and you forogot about cosmic rays :) -Steve