RCS

The modern successor of SMS and MMS

Rich Communication Services (RCS) makes messaging more versatile, faster and internet-based

Rich Communication Services (RCS) is a communication protocol which was developed as a modern successor to SMS (Short Message Service) and MMS (Multimedia Messaging Service). RCS is based on the IP multimedia subsystem (IMS), an architecture which enables IP-based communication services such as voice over LTE (VoLTE), video calls and messaging. Unlike SMS which are transmitted over the signalling network (SS7), RCS uses a data connection (mobile data or WLAN) to transmit messages.

Important RCS functions

Versatile. Safe. Flexible. Reliable.

1. Advanced messaging features:

Send pictures, videos, audio files, and documents

Group chats with admin options

Read receipts and typing indicators (“Typing...”)

Messages with up to 8,000 characters (instead of 160 for SMS)

2. End-to-end communication over IP

Messages are transmitted over the internet which enables fast and efficient communication

End-to-end encryption (E2EE) can also be enabled on supported devices and networks (e.g., already active between Google Messages users, Apple followed suit at the end of 2024).

3. Network and device independence

RCS functions over various mobile network providers, if they support the protocol

It is integrated into modern messaging apps such as Google Messages, Apple Messages and Samsung Messages

4. Fallback mechanism:

If RCS is not available (e.g., due to a missing data connection or incompatible devices – this can be queried in real time via API at any time for an MSISDN), the service provider can use a fallback, e.g., sending an SMS or email.

RCS Business Messaging (RBM)

Immediate connection between customer and company

RCS Business Messaging (RBM) is an extension of RCS which was especially developed for communication between a business and its customers. While RCS modernizes person-to-person (P2P) messaging, RBM targets application-to-person and person-to-application (A2P/P2A) traffic, i.e., automated or semi-automated messages from businesses to end users. This also includes a return channel that allows customers to initiate a conversation with the business.

Architectural components

RCS Client: the app on the user's device (e.g., Google Messages)

RCS Server/Messaging-as-a-Platform (MaaP): operated by the mobile network provider or a third-party provider (e.g., Google Jibe Cloud)

IMS Core: mediates IP-based communication

Universal Profile: a standard defined by the GSMA that ensures interoperability between different providers and devices

Special characteristics of RBM

Branding: companies can display their logo, color scheme, and name.

Interactive elements: buttons for replies, links, calendar integration, product carousels.

Security: verified senders prevent spoofing and phishing.

Delivery reports: companies receive feedback on message status (delivered, read).

Conversational commerce: integration of chatbots or live agents for support or sales.

Differentiation between RCS and RBM

From a personal chat to a customer dialog – the most important differences at a glance

Characteristic	RCS (Rich Communication Services)	RBM (RCS Business Messaging)
Target group	End consumer (P2P communication)	Company ↔ Customer (A2P/P2A communikation)
Intended use	Chatting, group chats, media exchange	Customer service, marketing, transaction messages
Functionality	Text, images, videos, read receipt	Interactive buttons, carousels, images, videos, location sharing, data exchange, branding
Authentication	No special verification	Companies are verified (e.g., with logos, name, colors)
Platform	Messaging app with RCS support	Same app but with special business integration
Exemplary usage	Chat between two persons	Airline sends boarding pass; bank sends transaction information
Technical basis	IMS/IP-based communication	Uses RCS protocol + Messaging-as-a-Platform (MaaP)