Digital Distributed Antenna System (DDAS)

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.

We have considered the impact of our research within each of the four main areas identified by EPSRC, namely economy, knowledge, people and society.

Economy: As a project aimed at the commercialisation of research, this project will the judged at every stage on its economic impact, as its success depends upon it. We intend to engage particularly closely with a number of companies including Zinwave, who are keen to advanced their technologies to address the major challenge of high capacity wireless delivery in the coming years. They have skills that are fully complementary to those of the group and will allow much more efficient and cost-effective commercialisation. Their direct access to key customers is a major advantage to us.

Given that there has been a lot of interest in the technology, we anticipate that, should the technical and commercial development activities in DDAS go to plan, that there will be the opportunity for the creation of a commercialisation vehicle perhaps within some joint venture. This work will be supported in this goal by Cambridge Enterprise.

We are particularly excited that whilst the work began has a systems project (involving primarily hardware research with software support), it could well lead to a new service-industry concept where individuals can be provided flexibly with a new wireless service on an on-demand basis, without requiring expert installation, in a much more economic and energy-efficient manner than previously regarded possible. The economic benefits to the service industry are ones that we wish to explore fully in the proposed project.

Knowledge: Although much of our research has direct exploitative benefit, we believe that the knowledge that we generate also benefits those researching within the academic community both within our disciplines and elsewhere, and also non-academics. Also, we hope to educate and reach out to the public with the new technology through public seminars, presentations, demonstrations and exhibitions. We believe this is necessary as it is anticipated that this new technology will be part of everyone's life in the near future.

People: The Photonic Systems group has an excellent record of training students and staff, with its alumni going on to permanent positions in academia, industry, government and commerce. The student (Tongyun Li) and RA (M Crisp) who will be involved with this project will gain invaluable experience in taking a technology concept from university research into a commercial venture. The inclusion of activities such as projects by students from Engineering (including the CDT in Photonic Systems Development) and the Judge Business School will allow a wider pool of students, across the engineering, economics and business departments, to benefit from the project providing experience in finding potential applications and routes to market for a real technology under active commercialisation.

Society: The ability to provide high bandwidth services will continue the immense benefit that mobile technology has had for the wider society in people's day to day lives. Increasingly real-time monitoring will be crucial in healthcare and in a host of environmental applications such as pollution, security, transport and energy monitoring, and some would argue that the solution to climate change will rely heavily on advances in this technology. It is of great importance that high bandwidth solutions to the distribution of wireless services are found so that individuals can have the enhanced lifestyles to which they aspire.