> As an aside, it turns out that on CDMA at least, the list of cell phone 
> numbers that should start ringing during this 1.25 time fits in one or two 
> packets, and is sorted by phone number, so while you're listening, if you 
> hear a higher phone number in the list, you can power down. It turns out 
> you have to adjust the sleep timer depending on how many phone numbers you 
> listened to, because running the receiver heats up the quartz crystal 
> differently depending on how long it runs, so the timer runs at a 
> different speed, and you'll miss your wake-up window if you don't.  Pretty 
> intensely complicated inside there.

Yeh I imagine on a lot of systems that are operating right on the limit of 
what's possible there are cool things like this that have to be done.

On a side note, isn't that a pretty bad security design, in that your 
handset could (in theory) be able to display a list of all phone numbers 
called in your cell?  I mean your phone could just store the last few 
seconds worth of called-numbers in your cell, and then when you hear your 
target's phone ring, trial and error through the short-list for to get their 
number.

Post a reply to this message