receiving and sending sms through gsm modem

Question

How can I receive SMS through a GSM modem so that I can use this SMS for further processing and send back a reply SMS. I do not have particular idea on how to achieve this....... I prefer using java language for this project and I am using Linux OS.

Answer 1

You might want to give a look at SMSLib:

SMSLib is a programmer's library for sending and receiving SMS messages via a GSM modem or mobile phone. SMSLib also supports a few bulk SMS operators.

Answer 2

To send an SMS using a 3G modem, you need to use the appropriate AT commands. First you need to set the modem to text mode:

AT+CMGF=1

Then you send your message:

AT+CMGS=<number><CR>
<message><CTRL-Z>

Where <CR> is a carriage return (ASCII 13), and <message> is the message you want to send, <CTRL-Z> is ASCII 26, and <number> is the number you want to send your message to.

To read received messages, you do this:

AT+CMGL=<stat><CR>

Where <stat> is one of: "ALL", "REC UNREAD", "REC READ" (with the quotes), meaning all messages, unread messages, and read messages respectively.

To do this in Java you'll need to use the Java communications API. Here's a short example: http://java.sun.com/products/javacomm/reference/docs/API_users_guide_3.html