Free SMS Service & SMS Gateway

Nowadays many sites are coming up with free SMS services. You can send free SMS within India to any mobile number.

There are many questions arise at this point of time.

• How actually does this works?
  
• How SMS send over internet reaches mobile?
  
• How they are able to provide this service for free?
  
• Etc…

Let's have a look at these points. 

Explanation of above diagram:

Step1: User login to the web site that provides the Free SMS service and enters the mobile number (Destination mobile number) to which he/she wants to send the SMS.

Step2: The mobile number will be sent to the Web Hosting server through Internet.

Step3: The Web Hosting server is connected with a GSM modem or a mobile phone with GSM SIM card.

Step4: An opensource application like Gammu (http://www.gammu.org/) will be running in the Web Hosting Server which will actually communicate with the GSM Modem/Mobile Phone and send the SMS to the destination Mobile phone using the GSM technology.

Step5: The destination mobile number will receive the SMS which actually routed through SMS Gateway.

This Simple setup can be done by any individual with internet connection and a mobile phone with GSM SIM card. Nowadays there are many plans available with mobile operators providing unlimited SMS with some monthly minimal amount.

Hope this Helps!!