> Bill wrote:
>> You also have to add in receiver senseivity/antenna gain on each band.
>> Your test is still good because it is testing the raw coverage for that
>> phone model to a single tower over two bands. It may be that the
>> phone is optimized for 1900 Mhz and will give equal results on both
>> bands.

Actually you can ignore receiver sensitivity as long as the phone is
well designed and limited by the system noise - which is what I was
suggesting. I also mentioned antenna gains, as part of ERP on transmit
and as part of effective aperture in the handset (receiving).

decaturtxcowboy wrote:
> Bottom line is the *ad hoc* test showed similar efficacy of
> 800 MHz and 1900 MHz when used is a rural environment.
>
> Both Nokia phones were dual-band models.

Yes, that definitiely shows they had the same performance but it doesn't
say too much about the reason or whether there is was a frequency
dependency differentially affecting the transmission losses. For that
you need to do significantly more, as described.

For more detail on frequency dependent attenuation, look for a paper by
Brown & Currie. A microwave-millimeter model from them:

> ke = 0.5*f^(0.75)
>
> where f is in GHz, and ke is attenuation in dB/meter for 1 way
> propagation in the summer for coniferous and deciduous foliage.
> In the winter, ke is about a factor of 2 smaller.

which gives about .44 dB per meter at 850 MHz and .8 dB/meter at 1.9
GHz. If the path from the tower has significant foliage, there will be a
significant increase in attenuation, due only to the foliage, at 1.9 GHz.

g