Re: OJ`S CELL PHONE

[Phil Karn <karn@qualcomm.com>]

>It may be that the phone can be "pinged" unbeknownst to the owner, but
>I'm fairly confident that if the phone is shut off, you're safe.  The
>truly paranoid might consider stowing the phone inside some sort of RF
>cage, I guess, or maybe just throw it out the window :-)

I should have added in my remarks about registration that one very
easy way to "ping" a cellular phone is to call it. If the phone is
powered on and hears the page, it will automatically acknowledge it on
the access channel (the mobile-to-base link that is also used to
request a mobile-originated call). This will certainly reveal the
mobile's location to the closest cell.

Phil