Digital Distributed Antenna System (DDAS)

该项目将寻求将研究商业化，这些研究已经导致了无线服务分配中的新范式的发展。简而言之，目标产品将首次实现在传统互联网基础设施上分发多种射频服务。它将允许对这类服务进行全面远程管理和监测，并大幅增加回程能力。目前这一提议背后的理念赢得了2011年剑桥大学GB 5k企业家挑战赛。到目前为止，建筑物内DAS系统主要是模拟的，这导致可通过单独光纤传输的无线信道数量和容量受到限制。如果已经使用了数字系统，则它们通常被配置为用于已知的、预定的RF调制格式和协议，并且需要非常高带宽的数字链路来传输信号。到目前为止，这是可以接受的，因为传统的DAS系统一直被用来确保对移动服务的良好覆盖，而容量要求相对较低。然而，光纤上的模拟无线电和传统的数字DAS对于未来可能的用户需求都有相当大的限制，其中容量将第一次成为一个非常重要的问题，因为它将影响诸如移动视频等高带宽服务的增长。这是因为这两种传统技术基本上都使用大带宽，这就需要使用单独的回程光纤来寻址单独的天线。因此，这些系统在扩展到满足未来带宽需求所需的天线数量方面的能力变得有限，并且需要在DAS上承载信号的建筑物内的基站发生从IP互联网业务到移动通信标准的转换。因此，对于未来的系统来说，容量将变得与覆盖同样重要(甚至更重要)，因此需要一种新的技术。最近，我们设计了一个能够解决这个问题的系统概念(即使它能够使用低带宽链路，如双绞线)，并反过来提出了它将如何在未来实现一种新的商业模式来提供高带宽服务。这项技术不仅使通过硬件销售进行开发成为可能，还提供了一种新的服务模式，新公司可以采用这种新模式，实际上创造了相当于“云计算”的移动服务。因此，这个数字DAS(DDAS)项目旨在开发一种新型的DAS，它可以利用这些地方现有的以太网基础设施，使它们在经济上可行地安装。此外，它还提供了一种更灵活的方式来增加容量，因为无线电源是集中的。它打算将目前的低比特率数字DAS系统的实验室演示商业化。这项工作的技术方面将集中在原型系统上，以向潜在客户、投资者或合作者演示。商业发展计划将与客户和潜在的许可证持有人发展关系，同时制定一项商业计划，目的是在授权期结束时产生一家衍生公司。

This project will seek to commercialise research which has led to the development of a new paradigm in the distribution of wireless services. In short the targeted products will, for the first time, enable the distribution of multiple RF services over conventional internet infrastructure for the first time. It will allow full remote management and monitoring of such services, and enable a substantial increase in backhaul capacity. The concept behind this current proposal won the Cambridge University £5k Entrepreneur's Challenge in its field in 2011. To date in-building DAS systems have primarily been analogue and this results in limitations in the number of wireless channels, and hence the capacity, that can be transmitted over an individual optical fibre. If digital systems have been used, they have typically been configured for known, pre-determined, RF modulation formats and protocols, and require very high bandwidth digital links to transmit the signals. Up to now, this has been acceptable because conventional DAS systems have been used to ensure good coverage for mobile services with capacity requirements being relatively modest. However both analogue radio over fibre and conventional digital DAS have considerable limitations for likely future user needs where for the first time, capacity will become a very important issue, as it will affect the growth of high bandwidth services such as mobile video. This is because both conventional techniques essentially use large bandwidths which necessitate the use of individual back-haul fibres being required to address individual antennas. As such these systems become limited in their ability to scale to the numbers of antennas required to deliver on future bandwidth demands, and require the conversion from IP internet traffic to mobile communication standards to occur at a base station within the building from which the signals are carried on the DAS. For future systems therefore, where capacity will become as (and indeed more) important than coverage, a new technology is required. Recently we have devised a system concept able to solve this problem (even though it is able to use low bandwidth links such as twisted-pair cables), and in turn proposed how it would enable a new form of commercial model for the delivery of high bandwidth services in the future. The technology not only makes possible exploitation by hardware sales, but also offers the creation of new service models which a new companies could adopt, in effect creating the mobile service equivalent to 'cloud computing'. Thus this digital DAS (DDAS) project aims to develop a novel DAS which could take advantage of existing Ethernet infrastructure in such places to make them economically feasible to install. In addition, it offers a more flexible way of increasing capacity since the radio source is centralised. It intends to take the current laboratory demonstration of the low bit rate digital DAS system to commercialisation. The technical aspect of the work will focus on a prototype system to demonstrate to potential customers, investors or collaborators. The commercial development plan will develop relationships with customers and potential licensees while building a business plan with the aim of generating a spinout company at the end of the grant period.