SMS was yesterday: How RCS is revolutionizing messaging

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The classic SMS is getting on in years. While messenger apps such as WhatsApp, Telegram or iMessage have long offered features such as read receipts, multimedia support or end-to-end encryption, SMS is still limited to pure text with 160 characters. It is also susceptible to spam and fraud attempts, as it is not possible to authenticate the sender (see Figure 1).

Marius Obert

Marius Obert baut gerne Prototypen mit den neuesten Cloud-Technologien und spricht noch lieber darüber. Seine Karriere startete in der UI-Entwicklung im sonnigen Kalifornien. Während dieser Zeit lernte er Webtechnologien wie JavaScript im Allgemeinen und das gesamte Node.js-Ökosystem im Speziellen zu lieben.

Such fraudulent messages are widespread, as senders can easily disguise themselves as parcel service providers or banks. Without a means of verification, the average user has little chance of distinguishing legitimate messages from fraudulent ones.

With Rich Communication Services (RCS), however, there is a modern alternative that solves all these problems. It combines the universal accessibility of SMS with the features of modern messenger services. Developers can send interactive content, customers can reply directly in the messaging app and, thanks to authentication mechanisms, RCS is far less susceptible to spam than conventional SMS.

RCS versus RBM

In addition to RCS, which was developed as a modern replacement for SMS for private users, there is also RCS Business Messaging (RBM; see table) for companies and organizations using the same technology. RCS in peer-to-peer communication is therefore the direct successor to SMS and enables users to exchange messages with each other via their native messaging app. The most important features compared to SMS:

• Multimedia support: users can send high-resolution images, videos, GIFs or voice messages.
• Read receipts and typing notifications: Similar to WhatsApp or iMessage, users can see when a message has been read or the other person is typing. However, this feature is not implemented by all client-side apps.
• End-to-end encryption (E2EE): RCS messages between private individuals can be encrypted, but this depends on the end device. Apple does not yet support encryption, but has already announced the function.
• Group chats: Users can use group messages with modern functions such as reactions and media content.
• Comparison to MMS: MMS already offered a limited way to send multimedia before RCS, but was severely limited by high costs, declining support from network providers around the world and low quality.

RBM is the commercial version of RCS and allows businesses, government agencies and other organizations to communicate directly with users – similar to WhatsApp Business, but without a separate app. RBM offers:

• Verified senders: organizations must authenticate themselves, which significantly reduces spam and fraud. This is particularly important as fraudulent messages from fake banks or delivery services are widespread.
• Rich media content: In addition to text, images, videos, carousels and interactive buttons can be used. This makes it possible to offer simple and intuitive user interactions –, such as booking an appointment or redirecting a parcel directly in the messaging app without having to install a separate app.
• Automated communication via APIs: RBM can be integrated directly via APIs, allowing companies to send automated messages and manage customer interactions efficiently.
• Direct interaction: Recipients can reply directly to messages and communicate in real time.

Vergleich: RCS für Privatnutzer versus RCS Business Messaging
Feature	RCS für Privatnutzer	RCS Business Messaging
Multimedia-Unterstützung	✅ Bilder, Videos, Sprachnachrichten	✅ Bilder, Videos, Karussells, interaktive Buttons
Lesebestätigungen	✅ Ja	✅ Ja
Tippanzeige	✅ Ja	Je nach RBM-Implementierung
Ende-zu-Ende-Verschlüsselung	🔶 Möglich (abhängig von der Implementierung des Clients)	❌ Nein
Gruppenchats	✅ Ja	❌ Nein
Authentifizierte Absender	❌ Nein	✅ Ja
Automatisierung & APIs	❌ Nein	✅ Ja

Table: The differences between RCS and RBM

The history of RCS

RCS as a standard is anything but new. The GSM Association (GSMA) specified it back in 2008. The industry association for mobile operators, device manufacturers and network equipment suppliers is responsible for the standardization of mobile communications, including mobile standards such as 4G and 5G, and wanted to establish a modern messaging standard to replace SMS. However, mobile operators were reluctant to introduce RCS across the board as it required investment in new network technologies. Many providers also developed proprietary messaging services that were not interoperable. It was only when Google acquired Jibe Mobile in 2015, a company that developed a cloud-based RCS infrastructure, that the market started to move.

Because Google had a problem. Apple created iMessage, a closed messaging service that has been an integral part of the iPhone ecosystem since 2011. Especially in markets such as the USA, iMessage became a decisive selling point for iPhones, as it is seamlessly integrated into the Messages app and offers far more functions than SMS – including read receipts, multimedia support and end-to-end encryption. For Android, there was no unified messaging service that could compete with iMessage. While apps like WhatsApp or Telegram were available across platforms, Android lacked a native option with the same features.

So Google decided to actively promote RCS by providing the technology via the "Google Messages" app. Instead of waiting for network operators to set up their own RCS servers, Google created facts and helped itself. This is because the Jibe platform can deliver RCS messages directly to users – independently of the respective mobile network provider. Initially, many network operators remained skeptical and preferred their own implementations, which led to compatibility problems. Over time, however, RCS became the standard on Android, especially after Google began to provide RCS directly via its own servers. This broad support from Android led to more and more mobile operators adopting RCS to keep up with the growing demand.

An interesting special case is China, where RCS is marketed under the name "5G Messaging". Here, RCS was closely linked to the introduction of the 5G network and positioned as a modern alternative to SMS. Providers there are legally obliged to provide RCS. It is therefore hardly surprising that China is one of the countries with the highest RCS adoption.

The decisive turning point came in 2024, when Apple surprisingly announced that it would support RCS in iOS 18. This decision did not come out of nowhere: in the EU, the Digital Markets Act (DMA) had increased the pressure on Apple to open up closed ecosystems. Regulatory pressure to enable interoperability between messaging services also grew in China and other markets. Apple presumably responded to these developments by integrating RCS in order to anticipate legal and political consequences. With support from iOS, RCS became a genuine cross-platform standard for the first time.

Technical aspects

In contrast to traditional SMS, which works via the mobile network, RCS is based entirely on IP technology. This means that an active internet connection is required to send and receive messages –, whether via WLAN or mobile data. This architecture has some decisive advantages.

As RCS is not routed via conventional mobile networks, there are no roaming costs abroad, as RCS works under the same conditions worldwide as long as there is an Internet connection. In addition, the IP-based architecture enables larger data volumes and better multimedia support.

A central component of the RCS ecosystem is Google's Jibe platform, which builds a bridge between mobile network providers and end users. Jibe takes on various tasks:

• If a mobile network provider does not operate its own RCS infrastructure, it can use Jibe as a cloud-based alternative to in-house development to manage RCS messages.
• Jibe ensures interoperability between different networks by acting as a switching platform for RCS messages.
• In markets where mobile operators do not support RCS themselves, Google can use Jibe to establish a direct connection between the Google Messages app and RCS-enabled devices.

However, mobile operators are not forced to use Jibe. They can operate their own RCS servers and use their own infrastructure for message exchange. However, some providers have had to contend with technical problems with self-developed RCS implementations in the past. As a result, many network operators have now moved to the Jibe platform to ensure a more stable and simpler RCS deployment.

For companies, authorities, associations or other organizations, RCS is a powerful way to communicate with customers and members. The possible use cases are diverse:

• One-time passwords (OTP) for secure login to online services
• Delivery notifications with interactive tracking options
  Appointment reminders with the option to confirm or reschedule directly from the message
• Support requests with rich media elements such as FAQs, quick replies and AI-powered chatbots
• Marketing campaigns with images, videos and call-to-action buttons

RBM provider: The interface between developers and RCS

To enable organizations to use RCS for their communication, they rely on RBM providers. These service providers act as an interface between developers, mobile network providers and the RCS infrastructure. The best-known RBM providers include Twilio, Infobip, Vonage and Sinch.

RBM providers offer API interfaces via which they can send their RCS messages. These APIs enable not only the sending of standard messages, but also the integration of interactive elements such as buttons, images or carousels. RBM providers also take care of technical aspects such as the authentication of senders, the routing of messages and the fallback to SMS if a recipient does not support RCS.

A major advantage is the simple integration into existing communication systems. Many RBM providers already support existing messaging APIs, so there is no need to set up a completely new infrastructure. This makes RCS an attractive technology for modernizing communication with users without having to make large investments.

Higher user engagement through interactive content

For example, RCS messages can contain an embedded product image and a "Buy now" button. Customers no longer have to laboriously click on links that then open other apps – they can interact with the relevant content directly in the messaging app.

This improved user experience leads to higher conversion rates and stronger customer loyalty as communication becomes more intuitive and seamless.

Automatic outreach and seamless fallback to SMS

A common problem with modern messenger services is the fragmentation of the user base. While some customers use WhatsApp, others prefer Telegram or Signal. RCS eliminates this problem, as it is integrated directly into the smartphone's native messaging app.

However, there are still users whose mobile providers or devices do not support RCS (although all German mobile providers except 1&1 can now handle RCS). However, if you have an Android device, you can also send and receive RCS messages via Google. This is where the fallback mechanism comes into play: depending on the RBM provider used, an RCS message can be automatically converted into an SMS if the recipient does not have an RCS-capable device or network. This means that the message reaches the recipient regardless of the mobile operating system used, without any dependency on third-party apps.

Trusted communication through verified senders

A key problem with traditional SMS messages is their high susceptibility to fraud attempts. Spam messages, phishing attacks and forged senders are widespread because there is no reliable authentication.

With RCS Business Messaging (RBM), this problem is a thing of the past. Developers must be verified before use so that recipients can be sure that the message actually comes from the specified sender. In addition, the sender organization appears in the messaging app with its name and logo, which strengthens customer trust (see Figure 1). Verification usually takes place with Google or a local mobile provider and must be started separately for each region. However, good RBM providers often offer to help with this step in order to simplify the process.

This verification not only increases security, but also the likelihood that customers will respond to messages. Studies such as the GSMA's"RCS Business Messaging Research Study" from 2018 (page 16, Figure 15) show that users are more likely to interact with a message if they can clearly identify who the sender is.