Adtran improves timing on Deutsche Bahn rail network

  • October 23, 2023
  • Steve Rogerson

Deutsche Bahn is leveraging Alabama-based Adtran’s optical caesium atomic clock technology to bring precise timing to its nationwide railway network in Germany.

The primary reference time clock (ePRTC+) will let Deutsche Bahn ( implement predictive maintenance and other technological advances throughout its network. Deployed as part of a major upgrade to Germany’s railway infrastructure, the technology supports migration to the Future Railway Mobile Communication System (FRMCS) framework, an initiative that harnesses innovation to improve railway safety, reliability and efficiency.

“We’re helping transform the safety and efficiency of one of Europe’s largest transport infrastructures for both passenger and freight services,” said Stuart Broome, general manager of Emea sales at Adtran. “Our ePRTC+ technology is ideal for facilitating Deutsche Bahn’s smooth transition to FRMCS, and we’re excited to be playing our part in its transformative journey. Ultra-stable and highly accurate timing opens the door to a wide range of new applications, including sophisticated signalling, optimised train scheduling, efficient track switching and comprehensive asset management. Our unique innovation is helping to usher in a new era of connectivity, reliability and sustainability in the railway industry.”

Adtran’s Oscilloquartz ePTRC+ technology is providing timing delivery and assurance for Deutsche Bahn’s critical network infrastructure. It consists of the OSA 5440 core grandmaster, OSA 3350 ePRC+ and the OSA 3350 super enhanced primary reference clock (SePRC), delivering availability, precision and holdover capabilities. The OSA 3350 SePRC is a caesium atomic clock that surpasses current ITU-T standard G.811.1 through its optical pumping technology.

To ensure accurate and stable timing, it employs multi-band GNSS receivers to compensate for ionospheric disturbances. By enhancing GNSS reception and reducing reliance on satellite signals, it guarantees service availability and network performance, even in the face of cyber attacks. In the event of GNSS signal loss, it can maintain phase outputs within 100ns from UTC for up to 55 days.

Adtran’s partner Telent ( was the system integrator, carrying out installation, configuration and troubleshooting.

“It’s increasingly important for critical assets like national rail infrastructure to have precise and assured timing that’s invulnerable to GNSS interruption or failure,” said Klaus Scholz, head of fixed wireless at Telent. “By working closely with Adtran to deliver the benefits of its robust atomic caesium clock, we’re helping Deutsche Bahn ensure compliance with the most stringent regulations and guaranteeing the security of its operations. Adtran’s technology and our ongoing support are also enabling Deutsche Bahn to adopt FRMCS, bringing higher data rates, improved reliability, increased capacity and better support for multimedia applications.”

Adtran ( is a provider of open, disaggregated networking and communications that enable voice, data, video and internet communications across any network infrastructure. From the cloud edge to the subscriber edge, Adtran empowers communications service providers around the world to manage and scale services that connect people, places and things.