GNSS as primary timing reference

GNSS for Telecom Timing

Global Navigation Satellite Systems provide the primary timing reference for mobile transport networks. A GNSS receiver locked to GPS, Galileo, GLONASS, or BeiDou satellites can deliver time accuracy better than one hundred nanoseconds relative to UTC. In the telecom timing hierarchy, a GNSS-disciplined oscillator at the top of the PTP distribution chain serves as the Primary Reference Time Clock, defined in ITU-T G.8272. The PRTC feeds a PTP grandmaster clock that distributes time across the packet network. Operators typically deploy GNSS receivers at aggregation and core sites where they…