Iridium and Globalstar aren't geostationary. They are LEO not much higher than Starlink. Starlink is doing direct-to-cell. Talking to existing phones requires

Iridium and Globalstar aren't geostationary. They are LEO not much higher than Starlink. Starlink is doing direct-to-cell. Talking to existing phones requires a large antenna. The bandwidth for each device is slow, not enough for mobile data, but better than Iridium. I think they recently showed off voice calls.