RCS is a next-generation communication protocol with read receipts, group chat, support for high-definition images, and more. The goal with RCS is to bring SMS and MMS to feature parity with the likes of Facebook Messenger, and Google has been leading the charge on that front. Earlier this year, the company rebranded Messenger to Android Messages, making it the de facto messaging app for RCS.
Google is also working closely with carriers to make RCS ubiquitous on Android — the platform's answer to iMessage. There are inherent challenges involved in getting carriers to talk to one another over the protocol — over the years, carriers have built additional features into their own messaging clients as a means of differentiation. For instance, AT&T and T-Mobile both offer RCS, but their version isn't compatible with Sprint's implementation, which uses Google's recommended universal profile.
Rogers is another carrier that uses the standardized universal profile, and earlier this week the Canadian carrier announced that its RCS solution is interoperable with Sprint. To bring further intercompatibility among carriers, Google's VP of communication products Nick Fox said that the company is using a "hub" model to get carriers connected to one another over RCS. For instance, a carrier connected to the hub will be able to connect to all the other carriers also connected.
The model makes it far less cumbersome for carriers to get set up with RCS as they don't have to develop individual connections with other carriers, saving resources and time. The move should lead to more carriers adopting the messaging protocol in the future.