Optus aiming for 100% signal coverage in Australia with Starlink partnership

Optus has one-upped Telstra's Starlink announcement from last week, announcing they are going to use Starlink to offer a direct to mobile service that'll give Optus 100% coverage of the mainland Australia landmass (except the Australian Radio Quiet Zone, for obvious reasons) in open sky (so not indoors). Starting in late-2024 you'll get SMS availability all over the continent, with voice and data to follow in late 2025. I assume Optus is doing the same kinda thing as what T-Mobile is doing with SpaceX in the USA and what Apple does with Globalstar for their Emergency SOS via Satellite feature, which I think is LTE band 53/54 (aka S-Band/L-Band) - but T-Mobile says "vast majority of smartphones already on T‑Mobile’s network" will work with these satellites and the "vast majority" of smartphones do not have band 53/54 support, so I think they're using an existing LTE band re-broadcast from the satellite. Either way, very cool.