IEEE Spectrum: Unsafe At Any Airspeed?
May. 14th, 2008 03:13 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
daveonIEEE Spectrum: Unsafe At Any Airspeed?
Interesting stuff, and not entirely a surprise to me but some of the findings are worse than I would have anticipated.
" In March 2004, acting on a number of reports from general aviation pilots that Samsung SPH-N300 cellphones had caused their GPS receivers to lose satellite lock, NASA issued a technical memorandum that described emissions from this popular phone. It reported that there were emissions in the GPS band capable of causing interference. Disturbingly, though, they were low enough to comply with FCC emissions standards."
I know that we've had engineers invest heavily in potted plants to place between them and working prototype handsets when they saw the radiation and radio output data for them. I've also seen a theoretically ready to ship 3G handset that could "talk" to its test rig without the cable across the lab.
I've certainly left my phone on a couple of times by accident.
The core issue is that outside of the critical phases this should be less of a problem anyway, (although the input on the effect of the Samsung phones on GPS is interesting, especially as built in GPS becomes a standard in 3G devices). Part of the problem with spectrum "noise" is an artifact of phones not being designed to (a) move at multiple hundreds of kph and (b) be 5 miles _above_ the radio landscape. Both of these factors lead to a very unhappy core network on the ground. Put a normal phone into a landscape like that and it'll crank up the power trying to handshake with a basestation (or in the case of CDMA lots of basestations) and keep doing while moving. It's a mess.
What will happen in the near future is the plane will have a micro-cell onboard which means the phone will lock onto the local cell a few metres away and broadcast at minimum power. That shouldn't be a serious problem.
Of course, the more serious problem is passengers fighting their natural urges to beat the leaving hell out of the ass on their phone for an 8 hour transatlantic flight.
Interesting stuff, and not entirely a surprise to me but some of the findings are worse than I would have anticipated.
" In March 2004, acting on a number of reports from general aviation pilots that Samsung SPH-N300 cellphones had caused their GPS receivers to lose satellite lock, NASA issued a technical memorandum that described emissions from this popular phone. It reported that there were emissions in the GPS band capable of causing interference. Disturbingly, though, they were low enough to comply with FCC emissions standards."
I know that we've had engineers invest heavily in potted plants to place between them and working prototype handsets when they saw the radiation and radio output data for them. I've also seen a theoretically ready to ship 3G handset that could "talk" to its test rig without the cable across the lab.
I've certainly left my phone on a couple of times by accident.
The core issue is that outside of the critical phases this should be less of a problem anyway, (although the input on the effect of the Samsung phones on GPS is interesting, especially as built in GPS becomes a standard in 3G devices). Part of the problem with spectrum "noise" is an artifact of phones not being designed to (a) move at multiple hundreds of kph and (b) be 5 miles _above_ the radio landscape. Both of these factors lead to a very unhappy core network on the ground. Put a normal phone into a landscape like that and it'll crank up the power trying to handshake with a basestation (or in the case of CDMA lots of basestations) and keep doing while moving. It's a mess.
What will happen in the near future is the plane will have a micro-cell onboard which means the phone will lock onto the local cell a few metres away and broadcast at minimum power. That shouldn't be a serious problem.
Of course, the more serious problem is passengers fighting their natural urges to beat the leaving hell out of the ass on their phone for an 8 hour transatlantic flight.
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