> >>> My new Nokia 6010 has an interesting and somewhat annoying habit. If
>>> it's anywhere within a 5 foot radius of my PC speakers, I can hear it
>>> periodically transmitting something (sort of a rhythmic
>>> dum-diddy-dum-diddy-dum-dum-dum). Sounds like static, but definitely
>>> with a paced rhythm. I haven't timed the intervals exactly, but it
>>> seems to take place every 17-20 minutes. In a related activity, I
>>> hear a big burst of static on my PC speakers, and then some rhythmic
>>> noise, about 5-7 seconds before the cell phone begins to ring.
>>> This is the first cell phone I've had that caused these noises. Do I
>>> have a mutant phone? Is this anything to be concerned about?
>> It's not just the Nokia 6010. *Any* GSM will exhibit the
>> characteristics you refer to. It's the phone communicating with the
>> system periodically...
> True. I was told by a contact at ETSI (the organisation that defined
> many of the GSM standards) that this was originally an oversight --
> they had not realised that the modulation scheme was effectively 100%
> amplitude modulation, which would be "detected" by any rectifying
> circuit nearby. It caused a lot of consternation in the early days.
> The "solution" they eventually agreed was to reduce the power
> transmitted by the phones by a factor of 10. This had been proposed
> anyway, to reduce the cell size and hence increase system capacity
> (also to increase battery life).
> Phil McKerracher
>formatting link
So GSM that we have today is a patch on top a patch. Nice to think about that.