Today Chairman Carr released a blog: Boosting GPS and 911 for the USA. After the announcement, NextNav released the following statement from CEO Mariam Sorond: 

I applaud Chairman Carr for announcing an inquiry that cements the need for a complement and backup to GPS. This is a foundational step in responding to a critical national security need. As a leader in positioning, navigation, and timing, NextNav is ready to work alongside the Chairman and Commissioners, the talented FCC staff, and all those committed to winning the race to GPS resiliency.