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

世界上的无线设备越来越多，预计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的手机和手持设备，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。对于其中的许多项目来说，准确、分布式、可扩展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，因为它能够准确地导出1米以下的位置。所需的精度将小于十亿分之一秒（亚纳秒），例如，用于自动驾驶车辆的准确变道，增强现实中的用户定位以及用于监控和安全任务的无人机群的精确协调。虽然目前使用基于卫星的全球定位系统（GPS）及其等同物来实现亚米定位/亚纳秒定时精度，但它们依赖于上方天空的良好可见性，这在地下、建筑物内或城市峡谷中、高层建筑物之间是困难的，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，以及被敌对射弹摧毁;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。这些都需要创新和光纤、电子和无线技术的结合。现有系统的局限性以及时间同步和定位对我们未来技术驱动的经济的绝对必要性，需要一种基于亚纳秒时间同步和亚米级定位的替代方案。该项目将UCL创新者和Rinicom设计师以及系统集成商带来新的设计概念，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。这些信号将是光学信号，我们计划利用已经部署的光纤网络和电缆来分发它们。由于光缆永远不会远离无线基站，因此精确的定时信号将耦合到无线系统并通过空中传播到无线设备。所提出的设计包括使用数据分组来存储、跟踪和补偿由于环境（例如温度）变化而引起的变化的信号传播延迟的方法。我们计划通过实验证明这种方法的可行性，并使用无人机验证定位精度。

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.