Two Way SMS using GSM Modem :

With GSM Modem attached to your computer , you can send as well as receive the SMS on your computer . Even Received SMS gets stored in the database , so there is no problem of SIM’s memory getting full and deleting the messages from SIM . 

Even the Query can be answered automatically by the computer , if somebody wants to know the rates of particular product , he will just send the name of the product as SMS , computer will match the name from the database and respond it with the details and the rates of that product . 

With GSM Modem attached we can setup a automatic response system with computer . 

Figure 2 . Figure3.