SMS: Definition, Functioning, and Common Uses

Definition of SMS

To better understand the concept of SMS, let’s break down what SMS means and where this concept, which has been part of the communications system for over four decades, comes from.

Origin and Meaning of the Acronym SMS

SMS stands for Short Message Service, a system developed in the 1980s as part of the GSM (Global System for Mobile Communications) standard.

The goal was to enable the sending of text messages up to 160 characters between mobile phones using mobile signal networks. Despite its simplicity, SMS revolutionized mobile communication and at that time paved the way for modern instant messaging.

Brief History of SMS Development

1984 – Two German engineers, Friedhelm Hillebrand and Bernard Ghillebaert, first proposed the concept of SMS as part of GSM standards development.

1992 – The first SMS in history was sent from a computer to a mobile phone; the message content was "Merry Christmas".

1993 – The first mobile phones capable of sending SMS appear on the market, launched by Nokia.

1999 – SMS could be sent between different mobile networks, driving mass adoption.

2000-2010 – SMS reached its global peak, becoming the most widely used messaging medium in the world.

2010s – SMS began to lose popularity with the arrival of messaging apps like WhatsApp but remained key for notifications and verification.

Present – Although personal use has declined, SMS remains essential for banking services, alerts, marketing, and authentication (OTP).

How SMS Works

But how does SMS sending work? SMS allows sending short text messages through the mobile network and follows these steps:

• The user writes a message on their mobile phone and sends it to another device’s number.
• The message travels from the sender’s phone to the nearest cell tower and then through the operator’s network.
• The message reaches the Short Message Service Center (SMSC), where it is temporarily stored. It is then verified, and if the recipient’s number is active, the message is forwarded.
• Once the recipient’s phone is available, the message is delivered.

A simple system that revolutionized communication and still guarantees security beyond instant messaging systems today.

SMS Sending and Receiving Process

The sending and receiving of SMS may seem simple from the user’s perspective but involves several technical elements and coordinated steps in the mobile network backend.

Infrastructure Required for SMS Functioning

Below are the different factors required to enable SMS sending and receiving:

1. Mobile devices, which are the user terminals where messages are physically received. (User Terminals)

2. Base stations, the wireless communication antennas between mobile devices.

3. Mobile Switching Center (MSC), the central node of the mobile network, responsible for routing calls and messages.

5. Short Message Service Center (SMSC), the heart of the SMS system. Its main function is to receive, store, and forward messages. It also retries delivery if the recipient is out of coverage.

6. Location databases (HLR – Home Location Register and VLR – Visitor Location Register). The HLR contains the user’s permanent information such as phone number, service plan, and current location.

The VLR temporarily stores user information when the user is in a different area than their home region.

7. SMSC Gateway, used if the message is intended for a user with another operator or located in a different country, ensuring compatibility between different systems.

8. Signaling network, the network used to establish communication between the various elements of the mobile network.

Characteristics of SMS

As we have seen, one of the most striking and popular characteristics of SMS is the limitation in message length. Below we explain this further and list the different types of messages based on text length.

Maximum Message Length

The standard SMS accepts a maximum of 160 characters if only GSM alphabet characters (Latin letters, numbers, and some symbols) are used.

If special characters are added, the message becomes a Unicode SMS, meaning it can include accented letters, emojis, and special characters from other alphabets. The maximum limit in this case is 70 characters.

Beyond the standard and Unicode SMS, there is the concept of concatenated SMS, which extends the character limit by splitting the message into segments that the recipient’s phone joins and displays as one.

Technical Limitations and Advantages of SMS

Based on SMS’s historical and technical development, we can group the main advantages and some limitations due to its technical capacity as follows:

Advantages

• High delivery and read rates
• Universal reach
• Simple communication and easy to use

Limitations

• Message length limitation
• Cost per message
• No multimedia content support

Evolution and Future of SMS

We have reviewed 10 years of history since the creation and sending of the first message, but what are the predictions for the future of this powerful communication tool?

Changes in SMS Usage with the Arrival of New Technologies

One of the current phenomena of SMS is RCS SMS, considered the evolution of SMS, which allows sending enriched messages with text, images, videos, interactive buttons, etc., without the need for an external app.

Another trend in SMS integration as a communication and business strategy is personalization based on user behavior.

Future Outlook for Short Message Service in the Digital Era

So, what is SMS today? We can say that SMS has evolved from a system of short messages between people into a powerful business communication tool. Although in personal use it has lost ground to instant messaging apps, its simplicity, reliability, and universality ensure an important role in the future of communications, especially in business sectors.

If you want to learn more about it, don’t hesitate to contact the LabsMobile team.