Digital Distributed Antenna System (DDAS)

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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.