Why does my cell phone show "no service" periodically for a few hours?

[Darren_Garrison]

Maybe not unrelated to this?

AT&T is sending me a phone unsoliticited, activating it, and disabling my current phone?

I’ve gotten the texts that say “AT&T is shutting down our 3G network and your phone will be toast when we do,” blahblahblah. I’ve researched this and apparently my BlackBerry (unlocked and bought by me at amazon) is fine and will continue to work. But just now I got a text that says AT&T is sending me a new free cell phone to replace this one! And if I don’t activate it within 30 days, they will activate it automatically and my current phone will be disabled except for being able to call 911 an…

Changes in their service can mean changes in the signal reception for specific frequencies and specific tower locations.