I’ve had a few people ask me for details on this, so I thought I’d write up a brief mini-tutorial on how I did it. I’m no expert, so caveat emptor, but I did manage to get it working without too much hassle.
I have an iPhone 3G with the 3.1.2 update — I had canceled ATT’s service, but had not unlocked it. Unlocking was pretty easy — I just followed the directions found here. About the only thing I would add is to make sure you’ve turned off auto-syncing in iTunes so it doesn’t keep launching as you’re working through the steps. iTunes has to be closed for it to work.
Once my phone was unlocked, I bought a DTAC Simple SIM from 7-11 for 49 baht. While you’re at it, go ahead and buy a refill card of 100 or 500 minutes, as the SIM only includes a half hour of time or so. The rates are 1 baht per minute – about $2 US per hour. DTAC centers in the big cities apparently sell a data plan that gives you full-time unlimited access for a week or a month (1,000 baht), but I could only find the per-minute cards here in the islands.
After powering down your iPhone, the old SIM can easily be removed with the use of a toothpick or a thumbtack. Simply push the toothpick into the small hole by the headphones jack and pull out the card. Swap the cards and power up your phone and follow the English directions that come with the SIM. In about 5 or 10 minutes, you’ll get a confirmation SMS from DTAC and now you should be able to make calls. Adding minutes is easy and the directions are in English.
To get internet access, grab your phone and go to Settings/General/Network/Cellular Data Network and enter www.dtac.co.th for the APN setting. I had to call their support line for that step — they were very helpful. With that change, you should be online.
DTAC doesn’t support tethering but I really wanted to be able to use the iPhone for net access on my laptop. This following step is obviously not supported or approved by DTAC. A little internet sleuthing found a hacked DTAC profile that makes this possible. The instructions are in Thai but I fumbled around and figured it out. Simply copy and email this link to your iPhone email address: http://www.bommy999.com/iphone3g/dtac.mobileconfig and then open the mail on your phone. Click the link and your phone will offer to install the new profile. Reboot your iPhone (not sure if you need to but I did anyway) and tethering is now available under General/Network/Internet Tethering.
Keep in mind that your iPhone will burn through your minutes even when you’re not using it. I keep mine in Airplane Mode to save my minutes and turn it off when I want to go online. If you manage to get one of the all-you-can-eat access packages, you won’t have to worry about this. Dial *101*9# on your phone to check your minutes.
Edge speeds are pretty slow, so you won’t be streaming video or downloading music, but for checking your email or even uploading a simple blog post, it works fine. Sitting at a beach, drinking a cold beer and working online makes for a pretty damn nice office setting. Enjoy!