According to Reindert Hommes, co-founder of Tallgrass, the initiative began with a chance encounter. “I do a course on fibre optics for the Systems and Network Engineering Group at the University of Amsterdam at the science park,” he explains. “Through the course, I attended the presentation of one of my students, and there I met the guys from OPNT, which is a spin-off of the VU. This is the kind of encounter that Amsterdam Science Park makes possible.”
Together, Tallgrass and OPNT decided to take the White Rabbit timing accuracy protocol, developed by CERN and used in radio telescopes for space observation, and apply it to a commercial area: mobile telephony. “What mobile operators need is more accurate clock signals,” Hommes explains. “Because all calls using mobiles are allocated time slots, really accurate timing is essential for an efficient, reliable service.”
"Who knows, it could be the new GPS"
Once Tallgrass and OPNT had joined forces, Vodafone, already a Tallgrass customer, came on board, and engineers from the three concerns worked together to create a proof of concept. In February, sub-nanosecond accurate timeslots were delivered using the new system to a live Vodafone network, covering four sites over a distance of 320km – a global first.
“The live network was interrupted in the middle of the night and our system inserted,” says Hommes. “If we’d messed up, it would have made headlines. We had to move carefully, and luckily everything went well – in fact, it’s still running.”
The new system has several advantages over GPS. Above all, it’s more accurate: to within a nanosecond, or one-billionth of a second (the amount of time needed for light to travel 20cm. Marco Gorter of OPNT points out that further strengths include its “plug-and-play nature, ease of implementation and calibration.”
Having proved the system works, further development is not far away. “We expect a national roll-out in the future,” says Hommes. “The technology lends itself to location-based services. Who knows, it could be the new GPS.”