When Nanoseconds Matter: An Industry Day on Breakthrough Optical Technologies

While in everyday life we get by with minutes or seconds, nanoseconds matter in digital infrastructure. Without precise time, it would be impossible to ensure the reliable operation of networks, data centers, or security systems—and yet we rarely give it a second thought.

The transmission of precise time and its significance were among the main topics of Industry Day, organized by the CESNET association in collaboration with PEI-Genesis. The event took place on April 28, 2026, at the Army House in Prague and brought together experts from both research and industry—ranging from academic institutions and technology firms to representatives of security agencies.

Precise Time as the Foundation of Modern Infrastructure
The question of how to ensure reliable and precise time in modern systems was one of the main topics of the technical program. With the advent of 5G networks, the development of data centers, and demanding scientific applications, accuracy requirements are shifting to the nanosecond level. Without precise synchronization, for example, it would not be possible to correctly sequence financial transactions, operate 5G and more advanced networks, analyze security incidents, or coordinate the operation of large-scale distributed systems.

At the same time, it is becoming clear that commonly used satellite systems (GNSS) have their limitations—particularly in terms of resistance to interference or signal spoofing. For critical systems, they therefore represent a solution that needs to be supplemented with more reliable alternatives.

CESNET: Precise Time Distribution via Optical Fiber
At Industry Day, our colleagues Vladimír Smotlacha and Josef Vojtěch presented current activities in the field of precise time and frequency transmission via optical networks. In their presentation, they explained why Europe is gradually moving away from dependence on satellite systems and what role time distribution via optical fiber plays in this shift.

We have been addressing this issue for a long time, and today, on the CESNET network, we transmit time alongside data streams over more than 2,000 kilometers of optical routes without the individual services interfering with one another. Precise time signals can thus share infrastructure with high-speed data transmissions of up to 400 Gbit/s.

Technology in Practice: From Synchronization to Data Centers
White Rabbit technology plays a key role, enabling synchronization with an accuracy better than one nanosecond and using optical fibers to transmit the time signal—often directly within the same infrastructure that simultaneously carries regular data traffic.

In addition to the topic of precise time, Industry Day also focused on all-optical switches, which represent a new approach to data processing in data centers. These technologies demonstrate how optical principles are applied beyond time transmission itself and pave the way for more efficient and energy-saving infrastructure operation.

The program was complemented by additional presentations from our colleagues focusing on key trends in the development of optical technologies. Tomáš Novák discussed quantum key distribution (QKD) and its application in the field of cybersecurity. Martin Šlapák presented optical fibers as an infrastructure that enables not only data transmission but also the transmission of precise time and other advanced services.

Technologies Becoming a Reality
The Industry Day demonstrated that optical technologies are no longer just a topic of research but are gradually becoming part of real-world operations. From our perspective, it is crucial that we are able not only to develop and test these technologies, but also to validate them in practice and integrate them into existing infrastructure. Precise time, optical networks, and new approaches to data transmission thus point to where digital infrastructure will be heading in the coming years.

Would you like to review the presentations from Industry Day? 

Vladimír Smotlacha. Introduction to the topic of precise time 

Josef Vojtěch: CESNET e-infrastructure, time and frequency transmissions

Jan Hrabina: Coherent references and optical quantum clocks in Europe and the Czech Republic (FOREST initiative)

Tomáš Novák, Jaromír Šíma: Quantum Key Distribution for Symmetric Cryptography 

Martin Šlapák: Optical Fibers Monitor Themselves—Even Passively