Frequency vs Attenuation per KM in local loop

Does anyone know where I could get data(ideally a graph) regarding the
attenuation per KM (or other unit) vs frequency of the 'normal'(I realise
that many different cable types and ages are in use) local loop.

I have looked on google but can only find data on CAT 5 cables and the
data starts at 1Mhz

Thanks
Martin Warby


Martin Warby

"Martin Warby" <(E-Mail Removed)> wrote in message
news(E-Mail Removed)...
> Does anyone know where I could get data(ideally a graph) regarding the
> attenuation per KM (or other unit) vs frequency of the 'normal'(I realise
> that many different cable types and ages are in use) local loop.
>
> I have looked on google but can only find data on CAT 5 cables and the
> data starts at 1Mhz

Is this the sort of thing you want?

http://www.dslforum.org/PressRoom/Vienna_Summit/BT.ppt (go through the
slides - some are relevant)

http://xdsl.ftw.at/docs/papers/Nords...TM6_021t32.pdf

Here's an attenuation table based on the BTm model on the at 300kHz for 1km
length - from the second url..

Gauge mm Attenuation dB
0.32 12.348
0.4 11.55
0.5 10.301
0.63 9.297
0.9 7.86

Regards
Sunil

On Mon, 23 Aug 2004 04:03:06 +0100, Sunil Sood wrote:

>
> Is this the sort of thing you want?
>
> http://www.dslforum.org/PressRoom/Vienna_Summit/BT.ppt (go through the
> slides - some are relevant)
>
> http://xdsl.ftw.at/docs/papers/Nords...TM6_021t32.pdf
>
> Here's an attenuation table based on the BTm model on the at 300kHz for 1km
> length - from the second url..
>
> Gauge mm Attenuation dB
> 0.32 12.348
> 0.4 11.55
> 0.5 10.301
> 0.63 9.297
> 0.9 7.86
>
> Regards
> Sunil

Yes thats great thanks

Martin

In article <(E-Mail Removed)>,
"Sunil Sood" <(E-Mail Removed)> writes:
>
>
>
> "Martin Warby" <(E-Mail Removed)> wrote in message
> news(E-Mail Removed)...
>> Does anyone know where I could get data(ideally a graph) regarding the
>> attenuation per KM (or other unit) vs frequency of the 'normal'(I realise
>> that many different cable types and ages are in use) local loop.
>
> Is this the sort of thing you want?
>
> http://www.dslforum.org/PressRoom/Vienna_Summit/BT.ppt (go through the
> slides - some are relevant)
>
> http://xdsl.ftw.at/docs/papers/Nords...TM6_021t32.pdf
>
> Here's an attenuation table based on the BTm model on the at 300kHz for 1km
> length - from the second url..
>
> Gauge mm Attenuation dB
> 0.32 12.348
> 0.4 11.55
> 0.5 10.301
> 0.63 9.297
> 0.9 7.86

That's very interesting. The other data it would be useful to know is
what guages of wires are typically encountered on the local loop on BT's
network.

Following what BT have claimed for the likely distance reach of ADSL, as
restrictions are relaxed, there seems to have been a sudden shift from
using 10 dB per km, to using 7 dB per km. Without any data to base it
on, I'd always assumed BT were craftily jumping from using a figure
which might be typical of the average line (perhaps 10 dB per km) to
using one more typical of the best cases (perhaps 7 dB per km). I'd say
the data above provides a little crumb of support for my case.

In practice, of course there might be a mixture of guages along
the path, with the junctions adding to the loss.

Armed with the above attenuation data, what do those who have a
knowledge of the mix of cable on the local loop reckon would be
a likely average loss per km, on a typical line?

--
Tim Clark