Accurate Time and radio signal distribution through Optical access networks to enable sub-Metre positioning accuracy (ATOM)

The world is filling up with wireless devices and is expected to have over 50 billion connected devices within in the coming decade. Some of such devices are mobile phones and handsets, others will be connected to machines that perform critical functions ranging from remote surgical systems to self-driving cars, security drones and highly connected accurate computing and communication systems. For many of these, accurate, distributed, scalable and synchronised electronic timing and time stamps are crucial to guarantee correct and safe operation by enabling accurate derivation of location, below 1 metre. The accuracy required would be less than a billionth of a second (sub-nanosecond) needed, for example, for accurate lane changing in autonomous vehicles, for user location in augmented reality and for precise co-ordination of a swarm of drones for monitoring and security missions. While satellite-based Global Positioning System (GPS) and its equivalents are currently used to enable sub-meter positioning/sub-nanosecond timing accuracy, they rely on good visibility of the sky above, which is difficult, even impossible underground, within buildings or in urban canyons, between high rise buildings. Furthermore, GPS satellites are vulnerable to being disabled by cyberattacks or solar flares, as well as destruction by hostile projectiles; an estimated cost of $1billion/day if GPS is disabled.

Our focus is the design and implementation of systems satisfying such demanding and challenging requirements. These require innovation and the combination of optical fibre, electronics and wireless techniques. Limitations of existing systems and the absolute necessity of time synchronisation and positioning for our future technology driven economy, an alternative based sub-nanosecond time synchronisation and sub-meter positioning is needed.

This project brings UCL innovators and Rinicom designers and system integrators to produce new design concept meeting the challenges described. We have successfully experimented with methods to generate highly accurate timing signals (sub-nanosecond accurate) using electronic and optical methods. These signals will be optical signals and we plan to distribute them by making use of already deployed fibre networks and cables. As optical cables are never far from wireless base stations, the accurate timing signals will be coupled to wireless systems and spread to wireless devices over the air. The proposed designs include methods to use data packets to store, track and compensate for the varying signal propagation delay due to environmental (e.g. temperature) changes. We plan to show experimentally the feasibility of this method and verify the positioning accuracy using drones.