what is that something missing for the difference

[#1]

using the formula
line length(km) =attenuation divided by 13.8.

b)then  this linkto get from my telephone exchange
the distance away I am from the exchange in Kilometers information
using the first calculation to  calculate attenuation
line length(km) =attenuation divided by 13.8.
using result from b)
2.7km = attenuation  / 13.8
rearranging gives
2.7k * 13.8 = ~37.8 dB

then thislink  to calculate speeds  after
inputting(or imputing) the Downstream Attenuation (in dB)
in the downstream attenuation box
it confirms distance
and types of ADSL speeds
confirming my theoretical max internet speeds
noted in my account area
what makes my actual(in reality speeds what they really are)
for information only purposes
(note)  i'm more than happy with my line speed @3MB

[#2]

I shall jot down a note -remember to look in at the library
to read something on electronic communications  

----------------------------------------end of part---------------------------------------

[#3]

that something
is the  ADSL signal power and  the SNR between my ISP,  the BT phone system  and my home's master socket
is that the answer ?
does anyone know whether
BT guarantee their ADSL signal voltage (max losses as a percentage) between ISP and anyone's home master socket
(is there a loss of signal clarity or interruptions by noise etc)between these  two points
that could make a BT  system  slow down  its line speed  to correct for bit errors
I just dont understand yet the calculations
is it the  inputting of  total dB  =  dB(attenuation)  + dB(SNR) that gives my real  max speed ?
this can be left for another day

[#4]

Hi giro,
and here was I going to tell you all the answers, but no, you don't want to know
Have you been on kitz website? It's a goldmine of information, what that girl doesn't know isn't worth knowing.
Jojo

[#5]

good evening jojo  
nice of you to say hi
you can tell me if you want to sometime
things are getting clearer in my mind
i know little  about BB and computers
have fun, you've  already  been working too hard  today
goodnight

[#6]

Does comparing broadband communications between you and the exchange with speaking to someone across the road help?
If there is no traffic you might be able to hear each other without shouting. With light traffic you might need to shout (increasing power a bit). With further increase in traffic noise you can't shout any louder, but might find speaking more slowly helps (lower speed, fewer high frequency tones used).
Even without traffic noise it is more difficult to hear if the other person is further away (increased attenuation).
Mix them all together and one might regard it a marvel that broadband works at all.

[#7]

Sorry but traffic has nothing to do with sync speed or attenuation.
If Giro does their research they will find attenuation is down to frequency and impedance.  With impedance being a product of frequency and  pure resistance  ???. So the copper is the pure resistance, the greater the length the higher is the resistance. Because attenuation is frequencies based the value which the router return is the average across the spectrum used. This is the reason that most users see an increase in attenuation when ADSL2+ is used.