1) I have heard of SIM900/SIM900A/SIM900D & SIM900 mini. I don't know whats the difference in them & which one should i choose for my project ?
2) I just want GSM module to transfer SMS and call to number in some critical time, so i don't need any fancy modem to this, i just want a model to be of that specific.
3) In search of models i found SIM900 MINI http://digipak.org/zencart/index.php?ma ... cts_id=197 which is quite small and low cost.
4) Is there any Software simulator for AT-Command, so that i can work in virtual environment (not using physical modem).
Any advice will be appreciated.