I still cannot find anything about "CDMA450 breaks any legislative power limits".
However, 450MHz can use higher transmit power without wasting it compared to
higher frequencies. No idea using higher transmit power classes on higher
frequenceis which anyway cannot bend around corners, through windows,etc .
There is little sense in blasting out a lot of power which doesn't anyway get behind
the larger building or over and behind a nearby hill.
That is why the old NMT450 used more RF power than later and higher frequency GSM,
especially the car-mounted NMTs, another different power class, as battery power consumptions
wasn't critical in the car.
Simple, yes??
Ilmarinen
That is, NMT was deployed on firts 450MHz, then on 900MHz.
GSM on 900MHz and 1800MHz
The higher the frequency, the more demand for (almost) line-of-sight
to the basestation, and thus smart with lesser transmit power, especially
as the higher frequencies are deployed in high density user areas, so
smaller cells are needed anyway.
That "hierarchical thing" (which either demands two bands for every
operator or cooperation)
That is, as soon as one goes outside cities,etc, where both 900 and 1800MHz
is used, there will be only 900MHz basestations. (except for
"hot spots", factories, popular recreation areas, larger crossings,etc)
And this gets even better with 3G at 2-2.5 MHz, both slightly higher
frequency and higher speeds and if out of coverage, fallback to GPRS
and in the future EDGE. (as thought and specified in the finnish 3G licenses) |
