Light squared. They imploded and became Ligado. Also defunct.
You might even find some of my comments in an email thread from back then.
In a nutshell, some users require wider filters for applications such as timing, survey and of course the military signal. As a practical reality, there’s a limit to how narrow you can make the SAW filters in terms of manufacturing tolerance,
insertion loss, and even temperature coefficients.
Reassigning space to earth frequencies to permit terrestrial transmission is apparently something the FCC doesn’t learn from mistakes on.
Reassigning space to earth C band satellite downlink spectrum to cellular, while adjacent to spectrum used by radio altimeters wasn’t a brilliant idea. The fact that rollouts were delayed AFTER the spectrum auctions were completed and carriers
wanted to roll out equipment should say something.