Petabit Energy Aware Capacity Enhancement (PEACE)

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 fibre cables and the technologies associated with them. Indeed, the initial surge in web usage in the mid 1990s coincides with the commissioning of the first optically amplified transatlantic cable network, TAT12/13 allowing ready access to information otherwise inaccessible. Tremendous progress has been made since then, with the introduction of wavelength division multiplexing, where multiple colours of light are used to establish independent connections through the same fibre and coherent detection, the optical analogue of an advanced radio receiver able to detect both amplitude and frequency (or phase) modulation simultaneously enabling the information carrying capacity to be doubled and the required signal power to be reduced. To manage the costs, communication networks typically aggregate connections between many users onto a single communications link within the core of the network, avoiding the tremendous costs associated with dedicated links for all users across vast distances. Typically the trade of between cost and reliability has resulted in traffic from several thousand customers being aggregated onto a single fibre resulting in bit rates in the region of 100 Gbit/s per wavelength channel to support broadband connections of around 10 Mbit/s. However, this has resulted in intensities in optical fibres that are a million times greater than sunlight at the surface of the Earth's atmosphere and so the signal is significantly distorted by nonlinearly (a similar effect to overdriving load speakers). This distortion limits the maximum amount of information which may be transmitted across and optical fibre link, and unless combated, the nonlinear response will result in a capacity crunch, limiting access to the internet to today's levels.

This project aims to allow the continued increase of the bandwidth of these fibre networks underpinning modern communications, including 17.6 million UK mobile internet connections and 70% penetration of home broadband connections. To increase capacity we will maximise spectral use, by adapting techniques found in mobile phones for use in fibre networks, resolving the significant issues associated with processing data with 1,000,000 times greater bandwidth using a balance of digital and analogue electronic and optical processing. This will reduce cost, size and power consumption associated with producing Tb/s capacities per wavelength. Critically, the project will develop techniques to understand and mitigate the nonlinear signal distortions. Nonlinear distortions occur within a channel, between channels and between each channels and noise originating in the optical amplifiers. By transforming the signal mid way along the link, we will exploit the nonlinear response of the second half of the fibre link to cancel the nonlinear distortion of the first to minimise the impact of nonlinear distortion associated with the channels themselves, and optimise the configuration of the system to minimise the nonlinear interaction with the noise, resulting in orders of magnitude increases in the maximum capacity of the optical fibre system.

The primary societal impact of PEACE will be to significantly postpone the impending telecommunications capacity crunch and will consequently have significant overall economic impact. By working with UK Photonics Communications industry, solutions developed in PEACE will allow full penetration of broadband services and time for the development of service delivery platforms which enable outstanding service delivery, of for example, low latency high definition video conferencing for domestic use (eg Panasonic Life Wall). By allowing for the development of a core network of sufficient capacity, PEACE will enable the increased effectiveness of various e-initiatives, such as e-medicine and e-public services and will so contribute the development of the emerging e-culture and overall quality of life. Similarly, by preventing an exponential growth in network energy consumption, PEACE will ensure environmental sustainability. Scientifically, PEACE proposes to create a centre of excellence for nonlinear system design, favouring understanding and direct mitigation of impairments over simple acceptance. This will result in new approaches to system design; will uncover new aspects of nonlinear pulse dynamics. Specifically PEACE will:
1. Maintain a high quality core science programme in collaboration with UK partners within the network equipment and operator communities. Prof. Ellis has published over 175 peer reviewed conference and journal papers since entering academia in 2003, and collaborates widely in Europe, partnering in 4 EU Framework 6/7 projects since 2006, an activity worth an additional euro2.5M funding to his host institution. In addition to UK collaborations, Prof. Ellis intends to continue to play a leading role in major European programmes with major companies such as OFS Fitel, Oclaro, Alcatel-Lucent and Nokia Siemens Networks.
2. Integrate applied research projects within the programme to create industry-relevant technologies and products. Prof. Ellis will continue to generate valuable IP (1 patent application per year, one know how transfer, one patent license and one spin out company since 2003). This process will be managed by the Aston Business Partnership Unit.
3. Cluster UK-based ICT companies around the proposal ensuring the industrial relevance of the research and providing direct exploitation routes benefiting the UK economy. In addition to working with the major multi-national companies, the project will support the growth of existing SMEs by helping to develop innovative new products, enabling access new sources of research funding, providing training and PEACE will support the creation of new ventures. A recent example of the later is Prof Ellis' intellectual property contributing to the start up Pilot Photonics (founded in 2011). The Aston Business Partnership Unit will regularly assist in the assessment of patentable and or/commercialisable material within the project. The project will also recruit and train highly-skilled people to the direct benefit of UK and European industry.
4. Fostering public awareness through education and outreach programmes, encouraging all PhD students to participate in Aston Universities outreach program, and participating personally in appropriate events with a wider public audience. Press-releases to non-specialist journals and professional magazines will also be used to publicize breakthroughs of particular importance to the wider public.
Thus the overall program of research enabled by this project is expected to have wide ranging benefits to the scientific community (development of a new approach to communication system design) the communications industry (simultaneous increase in available capacity and reduction in energy consumption) and wider society (continued growth of electronic communications).