(keitai-l) Re: The Sanyo scp5000, and the eclipse of the palmtop?

From: Eric Hildum <Eric_Hildum_at_itochu.net>
Date: 08/28/01
Message-ID: <B7B1499B.4989%Eric_Hildum@itochu.net>
Sleep doesn't cut it. The devices need to be off to prevent problems.

The interference problem is actual much larger and more complex than most
people realize, especially where device now have solid state controls
instead of physical switches. With multiple reflections, it is possible to
have a very strong signal even from a nominally weak transmitter.

For example, I know of a case in Japan where an apartment was destroyed by
fire because an electric heater was turned on by a keitai accidentally. This
was in July - the heater had been stored under a table for the summer, but
not unplugged. The signal from a keitai turned it on, and it set some
adjacent papers on fire.

There are a number of suspected cases of interference with aircraft systems
from passenger and crew portable devices, but as the incidents did not
result in a serious situation, no extensive investigation was done (yet).


on 01.8.28 0:15 PM, Benjamin Kowarsch at benjk@mac.com wrote:

>> Actually, for many of those cases, the transmitter is not the only source of
>> concern. The radiated signal from the internal clock DRAM refresh and the
>> like are potential sources of interference, especially if the device has
>> been physically opened after manufacture for service or upgrade (typically,
>> the RF shielding is misaligned or damaged enough during service to render it
>> ineffective).
>> 
>> That is the reason you are asked to turn off even devices that do not
>> intentionally radiate - like walkmans, computers, PDAs, etc.
> 
> What about devices that are put to sleep, i.e. PDA or notebook computer ?
> 
> And in case the DRAM refresh is so much of a culprit that sleep mode
> doesn't suffice, what about devices that use static RAM, i.e. Newton ?
> 
> I guess, enforcement will really get interesting with Bluetooth. Say,
> you are on a plane, shortly after the take off period is completed
> and you are allowed to use your notebook, which talks to your mobile
> phone in a bag or in your pocket to connect to whatever data service.
> Nobody sees your mobile phone is on and in use.
> 
> Perhaps, airlines will feel themselves under pressure to offer on
> board Internet simply to provide an alternative to using one's phone
> remotely.

-- 
Eric Hildum 


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Received on Tue Aug 28 23:03:06 2001