Before explaining how SMS-Gateway works. Let us understand the definition of SMS-Gateway.
What is SMS-Gateway?
According to Wikipedia “An SMS gateway or MMS gateway allows a computer to send or receive Short Message Service (SMS) or Multimedia Messaging Service (MMS) transmissions to or from a telecommunications network. Most messages are eventually routed into the mobile phone networks. Many SMS gateways support media conversion from email and other formats.”
Let’s now go through how SMS-Gateway works?
SMS-Gateway is basically a channel (website) from which we can send or receive SMS from the Telecom Operator, which then routed to the mobile phones.
Web-Application basically allows the Users’ to send messages to the large audience without knowing the internal process that is running behind the scene. The messages are written in a user-friendly language in the application is translated to the Mobile-Carrier compatible language which would be transmitted to the Telecom Operator and later to the Mobile phone users.
An SMS-Gateway is basically a Software as a Service (SaaS), or a well-documented API which can be integrated into the server. It basically interacts with the SMSC (Short Messaging Service Center) at which the Bulk-SMS application is connected, its functions are to convert the incoming SMS request into a format that is compatible with SMSC (Short Messaging Service Center).
Whenever Users’ send SMS from the Bulk messaging software, the software first asks for the SMS type which the user selects in the messaging application from which the gateway understand that in which SMSC (Short Messaging Service Center) it has to transmit the message. SMS type is of two types in India Promotional and Transactional SMS. Promotional SMS is basically the SMSC (Short Messaging Service Center) which doesn’t allow SMS to the numbers that are subscribed to DND (Do Not Disturb), and there is also a time limit restrictions, which means these SMSC (Short Messaging Service Center) are online from 9AM to 9PM after that the SMSC (Short Messaging Service Center) went offline, means they won’t accept any messages. Transactional SMS is basically used to send Information related SMS which means these SMSC (Short Messaging Service Center) are available 24*7 and can even send SMS to the DND(Do Not Disturb) numbers as well.
The messages request that is sent from the website are in the form of HTTP (hypertext transfer protocol) or script that sends the messages to the gateway which is connected to the server. Basically, the script converts all the text messages in the form URL encoded format so that the SMS Gateway could understand the messages. Typically the Gateway HTTP request may look like this:-
https://www.pingsms.in/cgi-bin/sendsms?account=test&password=1234&destination=7005629504&textmessage=For+bulk+SMS+Visit+www+%.+pingsms+%.+in
Where,
www.pingsms.in = website URL.
account = username of the gateway.
password = password of the gateway.
destination = Destination Mobile number.
textmessage = SMS text message (160char max for one API URL)
Once the messages are sent from the web application to the SMSC (Short Messaging Service Center), then the job of SMSC(Short Messaging Service Center) center starts. SMSC (Short Messaging Service Center) center are basically located at the Telecom Operator switching center. Therefore lets us understand how the SMSC (Short Messaging Service Center) works.
An SMS center or SMSC(Short Messaging Service Center) is basically responsible for handlining the messages request in the wireless network. whenever a message is sent from the Bulk messaging application it will first reach to the SMS center. The SMS center then looks for the SMS center from which the mobile phone user is connected, in this process the SMS center forward the messages to many different SMS center until the destination SMS center is located. The SMS center also stores the messages if the user is unavailable and once the user is available the messages are received to the mobile recipient.
The Telecom Operator basically build SMSC in order to communicate between the SMS gateway and the wireless network. Every mobile phone has its own registered SMSC gateway through which the user is capable of receiving the messages.
Once the telecom operator finds out the base station through the mobile phone is connected then the telecom operator SMSC sends the messages to the mobile phone and the user can see the messages on their mobile phone. This is how the internal process of SMS-Gateway works.
So, before reading any SMS on your phone, just think about how far the message traveled in order to reach your mobile phone.
