For rural/remote 3G data it is best to speak with neighbors to see what they are using. In theory CAT/TrueMove H on 850 MHz, TOT on 2100 MHz might have coverage. I wouldn't expect DTAC or AIS to have 3G coverage, generally speaking. I keep a CAT/TrueMove H 850 SIM just for this purpose (between Phrae and Lamphang).

Assuming 3G coverage from CAT/TrueMove H or TOT I might use one of those for any USB aircard application, rather than DTAC.

Assuming you live there you could also look into one of the P2P WiFi solutions like TOT-Wi-NET, AIS Air-NET, 3BB Wireless. These get pretty good reviews.

It's still not clear to me why TrueMove migrated you to CAT/TrueMove H/850 MHz 3G or even Real Move/2100 MHz 3G, given that your phone does not support these frequencies - you'll still have to roam back onto TrueMove GSM1800. I can only chalk it up to rural confusion, or maybe a desire to migrate anyone who comes in to the shop off of the, what looked like, soon to be expiring TrueMove GSM 1800?

FWIW, you can match low international calling rates with a local phone card, which provides free local access. http://www.thaitelephone.com/EN/call...enet/index.php