White Rabbit Collaboration

IQD Frequency Products is a member of the White Rabbit Collaboration

What is the White Rabbit Collaboration?

The White Rabbit Collaboration (WRC) is an initiative launched by CERN, the European Laboratory for Particle Physics, to foster the uptake by industry of the White Rabbit technology. This open-source technology provides a fully deterministic Ethernet-based network for general purpose data transfer as well as sub-nanosecond accuracy time and frequency transfer based on IEEE1588 (PTP). White Rabbit was born at CERN more than a decade ago as result of a joint effort with companies and institutes.
The WRC is a membership-based global community whose objective is to maintain a high-performance open-source technology that meets the needs of users, as well asprovide dedicated support and training, facilitate R&D projects between entities with common interests and complementary expertise and establish a testing ecosystem fostering trust in products that incorporate the open-source technology.


New emerging technologies have more stringent synchronisation requirements and there is an ever-growing overreliance on Global Navigation Satellite System (GNSS) for the distribution of time.

The WRC exists to bring stakeholders of the technology together, identify common interests and development needs, and define together the future of WR.

The WRC wants to foster the uptake of the technology in new domains and to become the global reference point for White Rabbit technology.

White Rabbit Switch (v4)

IQD, GMV and CERN are working together to realise a commercially available White Rabbit Switch box built to Version 4 of the design. The original Version 4 WRS, designed by CERN, includes a number of upgrades from Version 3, i.e. 10 Gbps Ethernet, hot swappable fans and PSUs. Most significantly to IQD, Version 4 also includes an expansion board slot; IQD is developing the first expansion board for use within WRSv4 and this expansion board will bring holdover capability to the White Rabbit Switch. IQD and GMV have committed to upholding the open hardware and are working with CERN through the WR Collaboration to support this.

The expansion board will include IQD's ICPT-1, a quantum atomic clock, which will be synchronised and disciplined to the clock on the main WRS. In the event that the main WRS detects that it is no longer locked to an external source, it will revert to the time signal from the ICPT-1 thus maintaining internal time and downstream time, aka holdover. IQD has already identified possible applications including switching to a redundant system after fault detections; during this event the holdover board would keep the WRS clock within a few nano seconds of the original signal, thus meaning no lock or time errors caused during the swap.


Designed into the WR Switch v4 is the ICPT-1, a rubidium oscillator designed using the Coherent Population Trap method. The ICPT-1 provides security and accuracy of signal continuity in case of temporary signal losses with its exceptional holdover ability, and can enable stability of accurate signals down to the picosecond level. This is the first time that holdover has been addressed in the open-source White Rabbit environment, and IQD is at the forefront of this technology.