Samsung flagships are usually among the last to receive major Android updates. Although the international versions of the Galaxy S9 and S9+ received the Android Pie update in late-December, its only now that the T-Mobile variant of the phone is starting to receive the OTA notification.
The update began rolling out yesterday brings Samsungs newest One UI skin over Android Pie. Not only this, but the firmware upgrade also includes support for RCS, the next generation of SMS/MMS. T-Mobiles firmware release notes also mention support for Band 28 (700MHz) while roaming, general bug fixes and system improvements.
Samsung Galaxy S9 and S9+
The Universal RCS Profile 1.0 brings support for read receipts, typing notifications, and sending large high-resolution images and large videos and files up to 100MB right out of the box using the default text messaging app. Group messaging also gains these features, however, all recipients must also support RCS in order for it to work.
Long overdue, efforts to bring next-generation messaging to Android devices were taken up by Google a few years ago. It worked to get carriers and phone manufacturers around the world onboard the same platform that would define the future of messaging on Android phones.
Its worth noting that the Universal Profile 1.0 is designed to support cross-network compatibility as long as other carriers are ready to interconnect with T-Mobile. Head to T-Mobiles RCS support page to see all supported phones.