Ultimate Passive Optical Network (UPON)

正如《华尔街日报》最近所讨论的那样，互联网的巨大成功可能要归功于看不见的地下和海底光缆以及相关技术的巨大容量。事实上，20世纪90年代中期网络使用的最初激增与第一个光学放大的跨大西洋电缆网络同时出现，使人们可以随时访问否则无法访问的信息。自那以后，技术取得了巨大的进步，自1983年英国电信（BT）引入单模光纤网络以来，所有的发展都利用了相同的物理基础设施，在30年的时间里实现了投资回报，容量几乎增加了5个数量级。然而，同样重要的是实际将客户连接到网络的“最后一英里”。虽然上个世纪的增长是由现有的铜缆基础设施支持的，但今天的网络在技术上更加断裂，按容量顺序分裂，从几kbit/s到几Gbit /s不等。5)这种传统网络，卫星分布（受低延迟的困扰），无线网络，光纤/铜混合（例如BT Infinity），同轴网络（有线电视），无源光网络和点对点光网络。这些解决方案中的每一个都提供了适合当今市场的独特功能，使网络运营商（如BT， Virgin， EE）和服务提供商之间的竞争成为可能。然而，除了基于光纤的解决方案，进一步的容量增长潜力是有限的。随着对通信服务应用的需求在数量上（如Twitter、YouTube、Facebook等）和带宽上（如HDTV、4k视频……）的持续增长，承载这些流量的通信系统的所有部分都必须能够以越来越高的速度运行。这种不断增长的容量需求只能通过不断升级网络所有部分的容量来处理，包括主要城市之间的长途链路，以及关键的“最后一英里”配电网络，这是该项目的重点。在UPON，而不是继续介绍这一系列平台，每个平台都针对特定的应用和数据速率进行了优化，我们将确定允许每个用户（使用单个连接）最大可能容量的网络配置，同时考虑到接入网本身的限制（由非线性和噪声之间的权衡引起）和核心网络中实际可实现的容量。这种独特的方法将允许开发具有最高增长潜力的单一优化网络配置。通过将技术经济模型视为网络设计的基本组成部分，与技术限制同等重要，还将确定、提出和证明具有成本效益的发展方案。这些场景将使网络容量和客户需求的逐步扩展成为可能，并在未来几十年开发带宽密集型应用程序。这将分三个阶段实现：实验和理论分析，地理布局对信号损耗的影响，各种形式的光学畸变的影响-最重要的是非线性畸变，其中光强度改变了光纤本身的折射率，以及成本；开发新技术，以提高每个客户可实现的数据速率，特别是利用一种新型光放大器的独特特性，即“光纤参数放大器”，以及专门为接入应用设计的新型传输光纤；实验演示证明了UPON配置的可行性，并影响了主要网络运营商的决策过程。如果UPON成功，它将为人与人之间的最高连接铺平道路，以最优的成本提供前所未有的体验质量。

As recently discussed by the Wall Street Journal, the remarkable success of the internet may be attributed to the tremendous capacity of unseen underground and undersea optical cables and the associated technologies. Indeed, the initial surge in web usage in the mid-1990s coincides with the first optically amplified transatlantic cable network allowing ready access to information otherwise inaccessible. Tremendous progress has been made since then, and since the introduction of the single mode optical fibre network by BT in 1983 all developments have exploited the same physical infrastructure, enabling return on investment over three decades in time and almost five orders of magnitude in capacity. However, of equal importance have been the "last mile" actually connecting customers to the network. Whilst growth in the last century was supported by the existing copper infrastructure, todays networks are more technologically fractured, split between (in order of capacity, ranging from a few kbit/s to a few Gbit.s) this legacy network, satellite distribution (plagued by poor latency), wireless networks, hybrid fibre/copper (eg BT Infinity), coaxial networks (cable TV), passive optical networks and point to point optical networks. Each of these solutions offer unique features suited to today's market, enabling competition between network operators (eg BT, Virgin, EE) as well as service providers. However, with the exception of fibre based solutions the potential for further capacity growth is limited. As demand for communication services applications continue to grow in number (e.g. Twitter, YouTube, Facebook, etc.) and in bandwidth (e.g. HDTV, 4k video...), all parts of the communication systems carrying this traffic must be able to operate at higher and higher speeds. This ever-growing capacity demand can only be handled by continually upgrading the capacity of all parts of the network, including long-haul links between major cities, as well as the critical 'last mile' distribution networks ending at or near the customer premises which are the focus of this project.In UPON, rather than continuing to introduce this series of platforms, each optimised for a specific application and data rate, we will identify the network configuration which allows the maximum possible capacity per user (with a single connection), considering both the limitations of the access network itself (arising from trade-off between nonlinearity and noise) and the practically achievable capacity in the core network. This unique approach will allow the development of a single, optimised network configuration with the highest possible growth potential. By considering techno-economic modelling as a fundamental component of the network design, with equal weight to technological constraints, will also identify, propose and demonstrate cost effective evolution scenarios. These scenarios will enable the gradual roll out of network capacity and customer demand and bandwidth intensive applications are developed over the next decades. This will be achieved in three phases: Experimental and theoretical analysis, of the impact of geographical layout on the signal loss, of the impact of various forms of optical distortions - most importantly nonlinear distortions where the light intensity alters the refractive index of the fibre itself, and cost; Development of novel technologies to enhance the achievable data rates for each customer, specifically exploiting the unique properties of a new form of optical amplifier the "Fibre Optic Parametric Amplifier", and new transmission fibres specifically designed for access applications; Experimental demonstrations proving the feasibility of the UPON configuration and influencing the decision making processes within major network operators.If UPON is successful, it will pave the way for the highest possible connectivity between people, offering unprecedented quality of experience, at the optimum cost.