VIAVI Launches ePRTC360+ Enhanced Primary Reference Time Clock

VIAVI Solutions Inc. (NASDAQ: VIAV) has introduced its patent-pending Cesium-less ePRTC360+™ Enhanced Primary Reference Time Clock (ePRTC) holdover solution, designed to support critical infrastructure including power grids, transportation, aviation, public…

VIAVI Solutions Inc. (NASDAQ: VIAV) has introduced its patent-pending Cesium-less ePRTC360+™ Enhanced Primary Reference Time Clock (ePRTC) holdover solution, designed to support critical infrastructure including power grids, transportation, aviation, public safety systems, 5G mobile networks, and AI data center environments in the face of GNSS timing disruptions.

The ePRTC360+ meets the requirements of the International Telecommunication Union standard ITU-T G.8272.1. This international standard specifies that ePRTC holdover performance must maintain short-term drift of less than 30 ns upon entering holdover and long-term drift of less than 100 ns over 14 days, with full traceability to UTC. These performance levels have traditionally been associated with Cesium-based clock technologies.

According to VIAVI, the ePRTC360+ is engineered to deliver Cesium-level holdover performance while offering flexibility for broader deployment across synchronization networks, including edge locations.

The solution has been tested in live-sky defense and commercial jamming and spoofing environments and has been integrated into VIAVI’s SecurePNT™ 6200 product series. It is designed to maintain 100 ns accuracy during GNSS-denied conditions through the resilient altGNSS GEO-L service, without a predefined time limitation. The system combines the VIAVI SecureTimeSM GEO anti-jamming antenna with an enhanced GNSS anti-spoofing antenna capable of receiving eGNSS GEO services with GPS/GNSS-NMA authentication for spoofing detection and mitigation.

VIAVI’s GEO-L service utilizes encrypted and directional L-band signals transmitted from geostationary satellites. When paired with the SecureTime GEO antenna, the service is designed to enhance resilience against interference and provide a stable timing reference for the ePRTC360+ internal Rubidium holdover oscillator. The architecture supports multi-orbit source switchover in scenarios where primary GNSS frequencies are disrupted.

The ePRTC360+ is intended to support synchronization architectures beyond core network environments and can also operate alongside Cesium-based systems within hybrid deployments. Through meshed PTP network feeds, operators can enhance synchronization redundancy and overall holdover reliability in the event of localized or regional GNSS interference.

The system is designed to address operational considerations associated with traditional holdover technologies, including environmental sensitivity, startup procedures, export classification requirements (ECCN 3A001.i), GNSS learning periods, and lifecycle management factors such as component replacement intervals.

The ePRTC360+ has been developed for streamlined integration into third-party grandmaster clock systems, supporting compliance with ePRTC requirements while aiming to optimize total cost of ownership.

The solution will be demonstrated at Stand 5B18 during Mobile World Congress 2026, taking place March 2–5 in Barcelona, Spain.