NIST is the official timekeeping organization in the United States for commercial applications. Connecting UTC(NIST) timescale to an ATSC 3.0 BPS leader station to provide traceable and a fully GNSS-independent time reference is key to build an alternate PNT system in a country-wide deployment.
In this paper, we present the proposal to feed BPS leader stations using High Accuracy White Rabbit synchronization through optical networks with UTC(NIST) timing. We also address how GNSS time servers and atomic clocks can be used as backups in case of failure.