"John Navas" <spamfilter0@navasgroup.com> wrote in message news:gbial2l5n3obv20987bu98je83edjegpbd@4ax.com...
> On 10 Nov 2006 16:22:43 -0800, scharf.steven@gmail.com wrote in
> <1163204563.543900.216750@b28g2000cwb.googlegroups .com>:
>
>>Nessnet wrote:
>>> #1 - you have shown NOTHING before... opinion yes, facts - no.
>
> I've actually posted authoritative citations.
>
>>> #2 number of towers IS a function of frequency used. Physics me boy...
>
> Physics has nothing to do with it. Try again.

Physics says that RF path propagation loss consists of two components:
Free Space Loss, and loss caused by absorption and scattering from
buildings and vegetation (trees) in the path.

Free Space loss is proportional to the operating frequency:
http://en.wikipedia.org/wiki/Free-space_loss

Using one of the commonly available online calculators, it is evident that
free space loss is increased approximately 7dB when changing the
operating frequency from 850MHz to 1900MHz:
http://www.terabeam.com/support/calc...space-loss.php

Loss attributed to trees in the RF path is also proportional to
operating frequency:
http://en.wikipedia.org/wiki/Weissberger's_Model

I haven't researched RF loss attributed to buildings in the path, but
there is no reason to believe that it would be substantially different
than losses from trees in the path.

--
John Richards (retired RF engineer)