AT&T lined up Messages by Google as the default messaging service for all its Android users, consolidating the app’s position as the dominant implementation of Rich Communication Service (RCS) for the smartphone platform in the US.

In March, Google and T-Mobile US forged a partnership around the platform, meaning Verizon is now the only nationwide US operator not to hold an RCS Android deal with the search giant.

RCS is called chat within the Android OS. Google explained it offers various advantages over SMS, inlcuding text over Wi-Fi, sending higher-resolution pictures and videos, viewing when a message is being answered, and modifying group chats.

For US operators, reliance on Google for RCS comes after a failed attempt to create a joint messaging service based on the standard.

Meanwhile, Google continuously upgraded its RCS app, adding web browser compatibility so users can text from multiple devices and end-to-end encryption for one-on-one conversations.

Messages by Google also steadily gained ground in the Android device sector: Samsung made it the default messaging app on its Galaxy S21 phones in Europe, with models for AT&T and T-Mobile expected to feature the service by default in the future.

Cross-network RCS messaging is a long-standing goal for the mobile industry.

In 2016, the GSMA, Google and a number of mobile operators partnered to create an open, consistent and globally interoperable messaging service for Android devices using RCS.