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

世界上到处都是无线设备，预计在未来十年内将有超过500亿台连接设备。其中一些设备是移动电话和手机，其他设备将连接到执行关键功能的机器，从远程手术系统到自动驾驶汽车，安全无人机和高度连接的精确计算和通信系统。对于其中许多，准确的，分布式的，可扩展的和同步的电子计时和时间戳对于确保正确和安全的操作至关重要，可以实现1米以下精确的位置推导。例如，自动驾驶汽车的准确变道、增强现实中的用户定位，以及用于监控和安全任务的一群无人机的精确协调，所需的精度将不到十亿分之一秒（亚纳秒）。虽然基于卫星的全球定位系统（GPS）及其等同物目前用于实现亚米定位/亚纳秒计时精度，但它们依赖于良好的天空能见度，这在地下、建筑物内或城市峡谷、高层建筑之间是困难的，甚至是不可能的。此外，GPS卫星很容易受到网络攻击或太阳耀斑的破坏，也容易被敌方发射物摧毁；如果GPS被禁用，估计每天的成本为10亿美元。我们的重点是设计和实现满足这些苛刻和具有挑战性的要求的系统。这需要创新和光纤、电子和无线技术的结合。现有系统的局限性和时间同步和定位对我们未来技术驱动经济的绝对必要性，需要一种基于亚纳秒时间同步和亚米定位的替代方案。该项目汇集了UCL的创新者和Rinicom的设计师和系统集成商，以产生新的设计概念，以满足所描述的挑战。我们已经成功地实验了使用电子和光学方法产生高精度定时信号（亚纳秒精度）的方法。这些信号将是光信号，我们计划利用已经部署的光纤网络和电缆来分发这些信号。由于光缆离无线基站永远不远，因此精确的定时信号将被耦合到无线系统中，并通过空气传播到无线设备中。提出的设计包括使用数据包来存储、跟踪和补偿由于环境（例如温度）变化而引起的信号传播延迟的方法。我们计划通过实验证明该方法的可行性，并利用无人机验证其定位精度。

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.