RCS Rich Communication Services
The SMS successor — typing indicators, read receipts, high-quality media, group chat. Standardised by the GSMA, in practice driven by Google.
Spec dates from 2008 but adoption took ~15 years. Google's Jibe platform acts as the "RCS mail server" for most operators. iOS 18 (September 2024) added RCS support after years of pressure — fixing the worst interop friction between iPhone and Android. End-to-end encryption is still Google-proprietary (Messages app) rather than part of the RCS standard. Universal Profile 3.0 is working on standardising E2EE.