How to Send an SMS Using a GSM Modem

1. Place a valid GSM-compatible SIM card in your GSM modem. Connect the modem to your computer using a Bluetooth link or a USB cable.
2. Launch the program that came with your modem. Select the command prompt option.
3. Type 'AT' and press 'Enter.' The modem should respond with 'OK.' This means that the connection between your computer and the modem works fine.
4. Type 'AT+CMGF=1' and press 'Enter.' This will make the modem operate in the SMS text mode.
5. Type 'AT+CMGW='+0000000000' (the phone number of the recipient instead of zeros) and press 'Enter.' The '>' sign should appear, indicating that you can now type the message.
6. Type the message of your SMS. Then type '+CMGW: 1,' which indicates the location of the text message in the storage of the modem.
7. Type 'AT+CMSS=1.' This command sends the SMS from the modem's storage. The computer should return 'OK.'