[geeks] a cell phone that doesn't suck

[David Muran-de Assereto]

<snip> bunch of stuff
>
> In theory, if I turn off the phone remove the battery and measure  
> the charge, then replace the battery, wait an extended period, then  
> test the current remaining in the battery and compare any loss to  
> the expected drain on a similar battery not installed in the device  
> I can assume the unit was off, as no current was used (can we all  
> agree that transmission and reception requires electricity in a  
> phone?). If I did all that, I've only proven that the phone didn't  
> use power. If I add a freq. counter to the mix and monitor emissions  
> whilst inside a farady cage for the extended period, I suppose I  
> could say that this one phone was actually off. But then there are  
> the thousands and thousands of other phone models I'd have to test  
> to *prove* my assertion.
>
>> We already know the opposite is true anyway.
>
> We do?
>
>
> How would you know the difference between the phone company altering  
> the phone while it is turned off vs. the phone company disabling  
> features on the phone once it turns on and access their network  
> (kill on connection, for instance)? Or a time limited activation,  
> that kills a feature/phone once a point in time is exceeded (like a  
> DHCP lease)?
>
>> Most cell phones can be remotely activated, turned off, or
>> reprogrammed, even if you have them "off".
>>
>> The only question is whether or not this is being abused or maybe how
>> much is it being abused.
>
> So the theory is that the phone company can reach out, activate an  
> otherwise powered down device, activate it, and do so in a manner  
> that doesn't alert the wearer/user? For this to be true, the phone  
> needs to be on when off (soft off you refer to), have a silent/ 
> invisible power-on sequence, and not drain the battery in a manner  
> to alert the user that the phone has a problem with the battery?
>
> There were recent reports that phone companies could turn on  
> microphones on cell phones that were powered on and listen to what  
> was going on (yay, one less tool for law enforcement!), but no one  
> ever asserted that the phone could be turned on remotely (I find it  
> hard to believe that cell phones have a "wake on WLAN" feature, but  
> I'd love to be proven wrong)...

OK, I'll take that swing:

"Experts say that the only defense is removing the battery"

http://blogs.abcnews.com/theblotter/2006/12/can_you_hear_me.html

There are a lot more references out there; this is just the first one  
I hit.

>
>
> The cell phone location the original article referred to was based  
> on the "beacon" signal that powered-on cell phones emit to alert the  
> network the phone is on and where it is on the network (what towers  
> should handle incoming calls to reach the phone) and triangulation  
> based on signal strength. It is not based on actual GPS readings, as  
> the stated resolution is "one block", GPS resolves much better than  
> that in my experience.

David Muran-de Assereto
dmuran at tuad.org

Sapere Aude!