Mobile Network Content Provider

Hello Everybody,

I am Edwin from Japan. I am doing some research on the mobile carriers of Thailand for work.

Here is the thing,

My company is having a customer who want to develop some applications for their employee in Thailand. The goal is to realize that some contents are only accessible via a cellphone (GPRS, EDGE or 3G).

As we know, one of the approach is to filter the IP address that mobile carriers use to route they users to access internet; the other way is to determine the client browser of a web server. (HTML tag or PHP user-agent string).

I have never been to Thailand, nor do I know Thai language. I wonder if the Thai carrier has something special for their content providers to determine the mobile access? Do they have strict contract and sim lock policy that only a limited types of devices can use their network?

Peace and Bless,

Edwin