[LINK] 5 Reasons Why E-Books Aren't There Yet

[Kim Holburn]

On 2011/Jun/09, at 10:37 PM, Ivan Trundle wrote:

> 
> On 09/06/2011, at 11:36 AM, Paul Brooks wrote:
> 
>> I am amazed the airlines allow people to power devices back up again midflight.
> 
> It's really only the take-off (particularly) and landing (slightly less so) that are super-critical.
> 
>> but somehow they've forgotten about all the wifi, bluetooth and 3G radios
> 
> Bluetooth is of negligible concern compared with wifi, remote control devices, CB radios, or 3G/4G services.

See I don't agree about wifi.  In a metal tube filled with people made of 90% or so of water (what is that percentage exactly?) wifi frequencies are absorbed by the water.  Wifi systems don't ramp up like cellphones do, they maintain the same power output.  I don't see wifi as that big a deal.  As for cellphones, cellphones ramp up the power output to try and find a base station kilometers away.  They are putting out far more power.  Although I should mention I have been on many flights where people left their phones on - talked, received calls.  I wonder if it really has any effect.  As for Bluetooth, Bluetooth may be low power but it is spread spectrum.  Spread over a wide range of frequencies.  In a small reflective tube this can affect sensitive radio equipment which is designed to pick this sort of stuff up.

> There is concern over nascent 4G services, primarily because of interference issues with local GPS equipment. They are wary of certain types of batteries after a few crashes involving freight planes which carried either lithium or lithium sulfur dioxide batteries, but that's a different problem.
> 
> One thing that is known (from research data) is that shavers, voice recorders, heart pacemakers, portable oxygen makers, and hearing aids are safe to use at any time, so stubbly almost-deaf dicky-hearted reporters are in the clear. Until you're travelling at 10,000ft, all other gear has to remain off.
> 
> It's up to each airline to determine what passengers can use and when: ie. there are only FAA advisories in place, not regulations.
> 
> There are advisories about where to avoid placing or storing such devices (proximity to cable bundles, flight controls, electronic and electrical bays, antennas, etc).
> 
> Nonetheless, for each plane that permits wifi use, it has to be certified as airworthy and must get FAA operational approval, which includes testing of all phases of flight and all components of the wifi (or ethernet) system. Any electronic device added to either cabin or flight deck and either permanently fixed or not must be able to be switched off instantly to gain certification.
> 
>> Do 3G-enabled iPads and tablets  have a readily accessable 'flight mode' switch?
> 
> iPads: yes.
> 
> Actually, the current thinking is that encouraging people to FIRST turn their certified device to flight mode, THEN to turn it off prior to take-off and landing - to ensure that when the device is switched on at cruising altitude, all hell doesn't break loose (or so they say - and possibly poor metaphor).
> 
> --
> Ivan Trundle
> http://itrundle.com ivan at itrundle.com ph 0418 244 259
> 
> 
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-- 
Kim Holburn
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