I was reading through one of the papers to which
Konrado5 had posted a link when I came across the following --
For VDSL2 systems that transmit over normal polyethylene-insulated pairs, there is a good
approximation of the attenuation A (in dB) at a certain frequency f:
A = k * l * sqrt(f), where k is a wire-dependant constant and l is the length of the wire.
An
xdslcmd info --Hlog command will provide the attenuation (in dB) for each tone (which can be easily converted to frequency) for any particular circuit. Let us assume that the electrical length of the circuit is known (by a TDR measurement). Rearranging the above equation such that all known parameters are on one side gives us --
k = A / (l * sqrt(f))Could that be a way to obtain a value range for k, given a sufficiently large set of data? Would subsequent manipulation of the data allow us to plot a generic graph of (electrical) line length versus attenuation VDSL2 circuits? At present, I have a number of partial ideas in mind but none will completely come to a conclusion.
From where could such a large set of data be obtained?
Tony's MyDSLWebStats, perhaps?
Can anyone "see" any potential in the above musing and possibly develop something from it?
