ePRTC360+ Enhanced Primary Reference Time Clock

The VIAVI ePRTC360+ is a Cesium-less enhanced Primary Reference Time Clock (ePRTC) designed to maintain precise timing through GNSS jamming and spoofing. It is intended to protect critical power grids, transportation, aviation and public safety systems, 5G mobile networks and AI data center infrastructure against GNSS timing disruptions.

Conventional ePRTC deployments depend on Cesium clocks, which are costly, operationally complex and difficult to scale beyond the network core. The ePRTC360+ provides Cesium-class holdover performance without Cesium hardware, allowing resilient timing in GNSS-contested environments.

The patent-pending solution has been tested in real-world defense and commercial GNSS jamming and spoofing environments and delivers <±100 ns holdover accuracy for over 360 days, with no time limit thereafter. It complies with the ePRTC holdover mask of ITU-T G.8272.1.

Deployment

ePRTC360+ clocks can be distributed across core, midhaul and edge synchronization networks, with meshed PTP backup feeds between clocks to increase sync network robustness and holdover reliability. An end-of-life Cesium clock at the network core can be replaced by multiple distributed ePRTC360+ clocks at the cost of a single Cesium clock.

GEO Timing and Antennas

The system uses GNSS-independent, UTC-traceable GEO timing signals via SecureTime GEO Services. The SecureTime altGNSS GEO-L helical antenna provides filtering attenuation for anti-jamming, and an enhanced GNSS antenna receives the eGNSS GEO service for GPS/GNSS NMA authentication to detect and mitigate spoofing.