Field test of ATSC 3.0/BPS precise time distribution 

The Broadcast Positioning System (BPS™) is a protocol for high-resolution time transfer between a reference clock at a ATSC 3.0 transmitter and a BPS receiver’s disciplined-clock output. Time transfer is a prerequisite for (and useful by-product of) positioning/navigation systems such as Global Navigation Satellite Systems (GNSS); for example, the Global Positioning System (GPS). In principle, BPS may address potential vulnerabilities in critical applications with GNSS dependence, mostly due to relatively weak GNSS signal levels at Earth’s surface. In 2024, BPS was added to the ATSC 3.0 transmission of the station KWGN in the Denver, Colorado metropolitan area. To measure BPS time transfer stability, BPS receivers were installed at two NIST campuses (the furthest: 106 km away) and compared against independent local atomic clock timescales. As an example, over one 50-day period and a non-line-of-sight (NLOS) transmission path of 30 km that includes terrain obstruction, we observed peak-to-peak time deviations on the order of tens of nanoseconds (including all variation of the reference time scales), a stability roughly comparable with ubiquitously deployed, single-band GPS receivers.

Jeff A. Sherman, David A. Howe | Time and Frequency Division, National Institute of Standards and Technology | Boulder, Colo., United States