sim application toolkit android

Question

I want to know what commands my sim card application toolkit is sending to the service provider.

I read somewhere that sim card application toolkit sends commands in the form of SMS or USSD. I want to know those commands. I'm using an android phone but I can use some other phone if required. I need a detailed answer since I'm not good in all of these things.

I actually want those commands so that I can create an application to make changes in stk. There are 5 steps in my orignal stk to make a recharge but I can reduce that in 2 steps if i will know exact commands so kindly guide me about it.

Answer 1

Yes, sim card application toolkit may send commands in the form of SMS or USSD to operator when needed. The sending of SMS or USSD, or even call to some specified number is trigger in modem. To find the SMS/USSD content, You need a modem log containing OTA info. You can't find those info from an Android logcat log for sure.