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mike[_19_]

On 27/12/2010 11:01, Terry Casey wrote:
In ,
says...

I had sky here in the UK and wifi for five+ yrs with no problems. The
sky box and router where approx 10ft away from each other with a brick
wall between though laptop and mobiles registered a strong signal in the
room where the sky was installed.

Signal level halves every time you double the distance so, taking your 10ft example, the
Sky box would see double the power if the separation was 5' and four times the power at
2' 6".

Put them next to each other - say 1' 3" apart, and the power level will increase
eightfold. In metric terms this would be 3m, 1.5m, 750cm& 375cm.

This is in free air - the brick wall, of course, will add additional attenuation!

It is interesting when the above is applied to mobile phones, where an additional factor
comes into play.

Because the base station has to handle many incoming transmissions at once, it likes to
have them all arriving at the same level, so there is an ongoing dialogue between base
and mobile which adjusts the mobile's transmit power appropriately.

Think about this the next time some parent starts crowing about their success in
preventing the big, bad mobile operator from putting up a mast near little Billy's
school, then happily send little Billy off to school with a microwave transmitter
(mobile) which now needs to transmit at a much higher power a mere 2cm from little
Billy's brain!

My virginmedia V+ box is 50cm from my Netgear routerwhich is 10 cm away
from my TV with no effect either.

Who is billy?

Mike