Data communications networks currently support PNT capabilities by carrying PNT aiding and augmentation data, GIS data, etc.; however, opportunities exist to exploit the synergy between RF-based PNT and communications by leveraging communications capabilities to provide PNT capabilities directly. This is consistent with the multiphenomenology vector of employing diverse sources and information paths, and would increase PNT robustness by offering services outside of traditional radionavigation spectrum. Leadership and initiative is needed to avoid stove-piped solutions, and detailed assessments regarding specific solutions are needed, so the US should establish a community of experts to pursue synergies between communications and PNT. Initially, the US should study the lessons learned from existing PNT/Communications fusion efforts, such as cellular and WiFi networks, iGPS, tactical radio networks, E911, the Air Force Satellite Control Network, and NASA‘s SCA to help determine what provides the best options for both systems and their users.

this might a common clock and reference frame encoded on all broadcast signals, and compatibility with indoor systems (such as WiFi)- if you get a signal from anything you get some location info.