No, I did not read the article . . . But, . . .
Yes, DSL speed varies by season . . . or rather, temperature.
But, this is really only the case for _aerial_copper_plant. Buried
plant is nearly the same temperature year round.
Yes, but it is more susceptible to long-term water infiltration, which
leads to longer-term speed drops. This is actually more difficult to
work with and test for.
Copper pair resistance changes with temperature. And, therefore, the
link speed of DSL will change depending upon the time of the year
(temperature) and geographic location.
If there is a difference of but a few degrees of temperature year round,
then no there will be no difference. But, if you live in the desert
southwest or even the mid-west where the temperatures can be 70-120
degrees different between seasons or even 40-70 degrees different
between night and day . . . you are going to have pronounced differences
in link speed.
You might. Or you might not. Around here, it's not unusual to see a
difference of a hundred degrees between summer and winter. Speaking
from a few decades of experience working with telecom up here, I'd be
tempted to say that either a circuit tends towards being problematic
or towards being reliable, and that where I've been able to ascertain
enough facts, there's a correlation with the age of the outdoor plant-
but that's only a loose correlation.
Worst cast, your link speed might vary 10-20%. The longer the cable
length from the central office, the more the variance will be. But,
this is something that must be measured on a case by case basis. And,
since much of the aerial plant has been replaced with buried plant, this
really isn't much of a problem anymore.
Buried plant mostly has more consistent (maybe less severe) problems,