Starlink satellites with Direct to Cell capabilities enable ubiquitous access to texting, calling, and browsing wherever you may be on land, lakes, or coastal waters. Direct to Cell will also connect IoT devices with common LTE standards.
Current partners:
T-Mobile - USA (https://www.t-mobile.com/news/un-carrier/t-mobile-takes-coverage-above-and-beyond-with-spacex)
Optus - Australia (https://www.optus.com.au/living-network/coverage/leosat)
Rogers - Canada (https://about.rogers.com/news-ideas/rogers-signs-agreement-with-spacex-to-bring-satellite-to-phone-coverage-to-canada/)
One NZ - New Zealand (https://one.nz/why-choose-us/spacex/)
Kiddi - Japan (https://www.au.com/english/lp/starlink/)
Salt - Switzerland (https://www.salt.ch/sites/default/files/2024-01/20240103-SpaceX-FirstMilestone_EN.pdf)
Entel - Chile (http://entel.cl/starlink)
Entel - Peru (https://www.entel.pe/noticias/alianza-de-entel-y-starlink-permitira-conectar-a-mas-peruanos/)
Kyivstar - Ukraine (https://www.veon.com/newsroom/press-releases/in-a-groundbreaking-agreement-veon-and-starlink-to-bring-starlink-direct-to-cell-satellite-connectivity-to-kyivstar-customers)
For me the important question is how usable this will be indoors. Some say it is impossible, some say it is a matter of frequency. Others again think a custom chip in the smart phone will make the difference.
I don't think it will work indoors. Ground-based base stations require a direct view, and we have a signal indoors because of the windows and other "slits" where radio waves can penetrate from the station nearby in the same plane.
The D2C satellite is very far away, and the satellite signal cannot reach the phone indoors, except maybe near windows.
Of note, in the very open outback of the desert regions in the USA, the 800MHz cellular bands can maintain RAN sessions with very good quality at the cell UT as much as 45 miles away from the 5G cell eNB. D2C uses the old PCS bands of 1910-1915MHz in the US. How far away are the D2Csats from a common terrestrial 5G cell UT?
The distance to D2C satellites is about 340 miles.
One issue that will have some effect is the battery time. Direct to cell will likely need full power from the handset.