Archived posting to the Leica Users Group, 2001/10/04
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> Re cellular phones and aircraft interference, let me clear up a few > misconceptions. > > GSM phones perform regular location updates and send measurement reports > back to the system using a crazy burst of signals at about 217Hz > (modulated > at the carrier freq). Any electrical apparatus with non-linear components > (e.g. a diode) will demodulate this, and here's your interferer. ANY? Even if it's well shielded? Do we even have GSM here in the US? I'm not sure, I only have experience with T/CDMA phones and systems. > And regarding the phones chewing up capacity when in the plane at > altitude > ... it just doesnt work like that. A phone in a high rise can be > 'heard' by > dozens of base stations, but it will only ever use a carrier from one of > them when it makes a call. The system chooses the most appropriate base > station, based on signal strength, quality and other parameters. Handing > over between cells is not an issue either. > Also, the radiation pattern from base stations is aimed towards > the ground, > not up in the air. That was my understanding also... > I hope this confuses things. You never know. Thanks! - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html