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MMS and SMS

What is SMS? A Look at the Ubiquitous Text Messaging Technology (5)

Short Message Service (SMS) is one of the most widely used communication technologies in the world, enabling simple, text-based messages to be sent between mobile devices. Despite the rise of instant messaging apps like WhatsApp, iMessage, and Telegram, SMS remains a crucial communication tool, particularly in business messaging, emergency alerts, and two-factor authentication (2FA). But what exactly is SMS, how does it work, and what are its limitations?

A Brief History of SMS

The first-ever SMS message was sent on December 3, 1992, by British engineer Neil Papworth, who transmitted “Merry Christmas” from a computer to a mobile phone on the Vodafone network. However, SMS as we know it took several years to become mainstream.

In the early 1990s, mobile networks were primarily designed for voice calls. Text messaging was an afterthought, introduced as part of GSM (Global System for Mobile Communications) networks in 1993. Early SMS adoption was slow because carriers initially restricted messaging to users on the same network. However, by the early 2000s, interoperability between networks was established, leading to a massive boom in SMS usage.

By 2010, SMS was at its peak, with trillions of messages sent annually. While the rise of over-the-top (OTT) messaging apps has cut into its dominance, SMS remains a reliable, universal, and carrier-backed messaging solution.

How SMS Works: The Basics of the Protocol

SMS is a store-and-forward messaging system that allows mobile users to send short text messages (up to 160 characters) over cellular networks. It operates on the Signaling System No. 7 (SS7) protocol, originally designed for call setup and management in telephone networks.

Here’s a high-level look at how SMS transmission works:

  • Message Creation: A user types and sends a message from their phone.
  • Message Routing: The message is sent to the nearest Short Message Service Center (SMSC), which acts as an intermediary between sender and receiver.
  • Store & Forward: If the recipient’s phone is turned off or out of coverage, the SMSC stores the message and attempts delivery later.
  • Message Delivery: When the recipient is reachable, the SMSC forwards the message to their phone, and a delivery receipt can be sent back to the sender.

Key Technical Aspects of SMS

  • Character Limit & Encoding: The 160-character limit is based on the GSM-7 encoding standard, which uses 7-bit characters. Longer messages are split into concatenated SMS, sent as multiple parts and reassembled on the recipient’s device.
  • Delivery Confirmation: SMS supports optional delivery receipts, confirming whether a message has been successfully received.
  • No Internet Required: Unlike instant messaging apps, SMS operates over cellular networks, meaning it doesn’t rely on Wi-Fi or mobile data.

Limitations of SMS

Despite its longevity and reliability, SMS has several technical and functional limitations:

1. Message Length Constraints

SMS is limited to 160 characters per message when using GSM-7 encoding. If special characters are used (such as emojis or non-Latin scripts), the encoding switches to Unicode (UCS-2), reducing the message length to 70 characters per SMS.

2. Lack of Rich Media Support

Standard SMS is text-only. If you want to send images, videos, or audio, you need Multimedia Messaging Service (MMS) or RCS (Rich Communication Services), both of which require carrier support.

3. No End-to-End Encryption

Unlike modern messaging apps that use end-to-end encryption (such as WhatsApp and Signal), SMS messages are unencrypted in transit, making them more susceptible to interception and man-in-the-middle attacks.

4. Reliance on Carrier Networks

SMS depends entirely on carrier networks, meaning messages may be delayed, filtered, or even blocked, particularly in high-volume A2P (Application-to-Person) messaging cases.

5. Spam & Phishing Risks

Since SMS does not have built-in spam detection, users are vulnerable to phishing attacks (smishing) where fraudsters impersonate banks, retailers, or government agencies to steal personal information.

Why SMS Is Still Relevant Today

Despite its limitations, SMS continues to be widely used in key areas:

  • Business Communications: Many companies use SMS for customer notifications, appointment reminders, and promotional messages.
  • Two-Factor Authentication (2FA): SMS-based OTP (One-Time Passwords) remain a common security measure for login verification.
  • Emergency Alerts: Governments and organizations rely on SMS to send critical weather warnings, disaster alerts, and public safety notices.
  • Global Reach: Unlike OTT messaging apps, which require an internet connection and app installation, SMS works on any phone, anywhere in the world.

The Future of SMS

While SMS is not going away anytime soon, newer technologies like RCS (Rich Communication Services) are being positioned as its successor. RCS, often called “SMS 2.0,” supports rich media, read receipts, typing indicators, and encryption—features similar to iMessage and WhatsApp. However, its adoption has been slow due to carrier inconsistencies and lack of universal support on Apple devices.

In the meantime, SMS continues to evolve through better security measures (such as Verified SMS and STIR/SHAKEN for call authentication) and improved filtering to reduce spam and fraud.

Conclusion

SMS may be an aging technology, but it remains a vital part of modern communication, thanks to its reliability, universal compatibility, and carrier support. Whether it’s used for personal messaging, business communications, or security authentication, SMS continues to play a crucial role in the global messaging ecosystem.

What is MMS? A Look at Multimedia Messaging Service (6)

Multimedia Messaging Service (MMS) is an extension of Short Message Service (SMS) that allows users to send and receive images, videos, audio, and rich media content via mobile networks. While SMS is limited to text-only messages, MMS provides a richer, more engaging communication experience.

Despite the rise of over-the-top (OTT) messaging apps like WhatsApp, iMessage, and Telegram, MMS remains a powerful tool for business communications, marketing campaigns, and customer engagement—particularly because it works natively on nearly all mobile devices without requiring an internet connection or third-party apps.

A Brief History of MMS

MMS was first introduced in 2002 as an enhancement to SMS, leveraging the same cellular infrastructure but with the added ability to send rich media. Unlike SMS, which is limited to 160 characters, MMS can carry images, video clips, audio files, and even formatted text, making it a significant upgrade in mobile messaging.

Initially, MMS adoption was slower than SMS due to:

  • Higher costs for sending and receiving messages
  • Carrier-specific restrictions and inconsistent implementations
  • Early mobile phones lacking strong media support

However, as smartphone adoption increased and mobile networks improved, MMS became a widely used medium for brand marketing, customer engagement, and business communications.

How MMS Works: The Basics of the Protocol

Unlike SMS, which is transmitted over the SS7 signaling network, MMS relies on packet-switched networks, meaning it works more like email than traditional text messaging.

Step-by-Step MMS Transmission

  • User Sends an MMS
      • The sender composes a multimedia message with images, videos, audio, or formatted text.
      • The message is packaged and sent to the user’s carrier network.
  • Message is Sent to the Multimedia Messaging Service Center (MMSC)
      • The carrier routes the message through an MMSC (Multimedia Messaging Service Center), which stores and processes the media.
  • Message Delivery Process
      • If the recipient’s phone supports MMS, the message is delivered directly.
      • If not, the recipient receives an SMS with a link to view the media via a web browser.
  • Recipient Downloads the MMS
    • The recipient’s phone downloads the multimedia content from the carrier’s servers, completing the transmission.

Key Technical Aspects of MMS

  • Increased Character Limit – Unlike SMS’s 160-character limit, MMS can include thousands of characters in formatted text.
  • Supports Rich Media – MMS allows for images, videos, GIFs, audio files, and slideshows.
  • No Internet Required – While MMS is delivered over mobile networks, it does not require mobile data or Wi-Fi to function.

Limitations of MMS

Despite its advantages, MMS has several technical and functional limitations that have prevented it from fully replacing SMS.

1. File Size Restrictions

MMS messages are limited in size depending on carrier policies. Typical MMS size limits are:

  • 300 KB to 600 KB per message on most carriers
  • Some networks allow up to 1 MB, but this is uncommon
  • Larger media files are compressed, often reducing quality

2. Inconsistent Carrier & Device Support

Not all mobile carriers or devices handle MMS in the same way. Some older or low-end phones may not properly receive MMS, instead displaying a link to view the media in a browser.

3. Higher Costs

MMS is often more expensive than SMS. While SMS costs fractions of a cent per message, MMS pricing is significantly higher, particularly for bulk messaging.

4. Slower Delivery Times

Because MMS messages contain larger files, they take longer to process and deliver than SMS. This makes real-time messaging less efficient compared to standard text messages.

5. No End-to-End Encryption

Like SMS, MMS lacks encryption, making it less secure than modern messaging apps like WhatsApp and Signal, which offer end-to-end encryption.

Why MMS is Still Relevant Today

Despite these limitations, MMS continues to play an important role in business communications, especially in industries that benefit from visual engagement.

Key Use Cases for MMS

  • Marketing & Promotions – Brands send rich media ads, GIFs, and product images directly to customers’ phones.
  • Customer Engagement – Companies use MMS for personalized messages, appointment reminders, and service updates.
  • Two-Factor Authentication (2FA) – MMS allows for more visually engaging authentication codes or security messages.
  • Retail & E-Commerce – Businesses send product previews, order confirmations, and shipping updates with images.
  • Healthcare & Telemedicine – Doctors and clinics share appointment details, test results, or prescription instructions via MMS.

The Future of MMS

While MMS remains a powerful messaging tool, newer technologies are beginning to replace it, particularly Rich Communication Services (RCS).

RCS: The Successor to MMS?

RCS, often referred to as “SMS/MMS 2.0,” offers richer media, typing indicators, read receipts, and encryption. Unlike MMS, which has file size restrictions and carrier dependencies, RCS operates more like an instant messaging service.

However, RCS adoption faces challenges:

  • Apple does not support RCS, making cross-platform messaging difficult.
  • Carrier adoption is inconsistent, with some networks lagging in support.

For now, MMS continues to be a viable solution for businesses looking for universally compatible, rich media messaging.

Conclusion

MMS may not be the most advanced messaging format, but it remains one of the few universal, carrier-supported options for rich media messaging. With its ability to send images, videos, and formatted text without requiring an internet connection, MMS is still a valuable tool for businesses, marketers, and service providers.