VIAVI Solutions has launched the patent-pending Cesium-less ePRTC360+ Enhanced Primary Reference Time Clock (ePRTC) holdover solution as an alternative to Cesium atomic clocks, targeting environments at risk from Global Navigation Satellite System (GNSS) timing disruptions. VIAVI positions the product for critical infrastructure including 5G mobile networks and AI data center infrastructure, in addition to power grids, transportation, aviation, and public safety systems.
VIAVI says ePRTC360+ meets International Telecommunication Union Telecommunication Standardization Sector (ITU-T) G.8272.1 requirements for Enhanced Primary Reference Time Clock holdover. The standard specifies short-term drift of less than 30 ns when entering holdover and long-term drift of less than 100 ns over 14 days, traceable to Coordinated Universal Time (UTC). VIAVI reports this level of performance was previously achieved only by Cesium atomic clocks.
“The Cesium-less ePRTC360+ exceeds leading-edge Cesium-level holdover performance and does this for significantly lower price,” said Doug Russell, Senior Vice President and General Manager, Aerospace and Defense, VIAVI. “This enables deployment across the sync network, particularly at edge sites which were previously cost-prohibitive with Cesium holdover clocks,”
According to VIAVI, ePRTC360+ has been successfully tested in live-sky defense and commercial jamming and spoofing environments and integrated into its SecurePNT 6200 product series. VIAVI states the technology can maintain 100 ns accuracy during GNSS-denied threats via its resilient altGNSS GEO-L service with no time limit, and it combines an augmented VIAVI SecureTime GEO anti-jamming antenna with an enhanced GNSS anti-spoofing antenna that also receives eGNSS GEO service with GPS or GNSS Navigation Message Authentication (NMA) for spoofing detection and mitigation.
VIAVI describes its altGNSS GEO-L service as GNSS-independent, using encrypted and highly directional L-band signals transmitted from geostationary satellites, in contrast to conventional GNSS omni-directional signals. VIAVI reports that, coupled with the augmented VIAVI SecureTime GEO antenna, GEO-L provides enhanced anti-jamming protection and a resilient timing reference for the ePRTC360+ internal Rubidium holdover oscillator, enabling smooth multi-orbit source switchover when primary GNSS frequencies are jammed, spoofed, or subject to meaconing attacks. VIAVI also says ePRTC360+ is designed for rapid integration into any vendor’s grandmaster clock system and is intended to reduce total cost of ownership versus Cesium clocks, citing Cesium-related constraints including shock sensitivity, multi-stage startup that can take days, Export Control Classification Number (ECCN) 3A001.i licensing for export, GNSS learning periods up to 40 days, strict shipping and storage protocols, and Cesium tube replacement about every seven years.
Source: VIAVI Solutions
