Energy efficient processes are increasingly key priorities for ICT companies with attention being paid to both ecological and economic drivers. Although in some cases the use of ICT can be beneficial to the environment (for example by reducing journeys and introducing more efficient business processes), countries are becoming increasingly aware of the very large growth in energy consumption of telecommunications companies. For instance in 2007 BT consumed 0.7% of the UK's total electricity usage. In particular, the predicted future growth in the number of connected devices, and the internet bandwidth of an order of magnitude or two is not practical if it leads to a corresponding growth in energy consumption. Regulations may therefore come soon, particularly if Governments mandate moves towards carbon neutrality. Therefore the applicants believe that this proposal is of great importance in seeking to establish the current limits on ICT performance due to known environmental concerns and then develop new ICT techniques to provide enhanced performance. In particular they believe that substantial advances can be achieved through the innovative use of renewable sources and the development of new architectures, protocols, and algorithms operating on hardware which will itself allows significant reductions in energy consumption. This will represent a significant departure from accepted practices where ICT services are provided to meet the growing demand, without any regard for the energy consequences of relative location of supply and demand. In this project therefore, we propose innovatively to consider optimised dynamic placement of ICT services, taking account of varying energy costs at producer and consumer. Energy consumption in networks today is typically highly confined in switching and routing centres. Therefore in the project we will consider block transmission of data between centres chosen for optimum renewable energy supply as power transmission losses will often make the shipping of power to cities (data centres/switching nodes in cities) unattractive. Variable renewable sources such as solar and wind pose fresh challenges in ICT installations and network design, and hence this project will also look at innovative methods of flexible power consumption of block data routers to address this effect. We tackle the challenge along three axes: (i) We seek to design a new generation of ICT infrastructure architectures by addressing the optimisation problem of placing compute and communication resources between the producer and consumer, with the (time-varying) constraint of minimising energy costs. Here the architectures will leverage the new hardware becoming available to allow low energy operation. (ii) We seek to design new protocols and algorithms to enable communications systems to adapt their speed and power consumption according to both the user demand and energy availability. (iii) We build on recent advances in hardware which allow the block routing of data at greatly reduced energy levels over electronic techniques and determine hardware configurations (using on chip monitoring for the first time) to support these dynamic energy and communications needs. Here new network components will be developed, leveraging for example recent significant advances made on developing lower power routing hardware with routing power levels of approximately 1 mW/Gb/s for ns block switching times. In order to ensure success, different companies will engage their expertise: BT, Ericsson, Telecom New Zealand, Cisco and BBC will play a key role in supporting the development of the network architectures, provide experimental support and traffic traces, and aid standards development. Solarflare, Broadcom, Cisco and the BBC will support our protocol and intelligent traffic solutions. Avago, Broadcom and Oclaro will play a key role in the hardware development.

Photonics has moved from a niche industry to being embedded in the majority of deployed systems, spanning sensing, biomedical devices and advanced manufacturing, through communications, ranging from chip-to-chip and wireless access to transcontinental scale, to display technologies, bringing higher resolution, lower energy operation and new ways of human-machine interaction. Its combination with electronics enables the Digital Future. The Government's UK Semiconductor Strategy and UK Wireless Infrastructure Strategy both recognise the need for highly trained people to lead developments in these technology areas, the Semiconductor Strategy referring explicitly to the role of CDTs in filling the current shortage of highly trained researchers. Our proposed CDT has been designed to meet this need. Currently manufactured systems are realised by combining separately developed photonics, electronic and wireless components. This approach is labour intensive and requires many electrical interconnects as well as optical alignment on the micron scale. Devices are optimised separately and then brought together to meet systems specifications. Such an approach, although it has delivered remarkable results, not least the communications systems upon which the internet and our Digital Future depends, limits the benefits that could come from systems-led co-design and the development of technologies for seamless integration of photonics, electronics and wireless. Our proposed CDT aims to provide multi-disciplinary training enabling researchers to create the optimally integrated, energy efficient, systems of the future. To realise such integrated systems requires researchers who have not only deep understanding of their specialist area, but also an excellent understanding across this interdisciplinary area ranging across the fields of photonics, electronics and wireless, hardware and software. We aim to meet this important need by building upon the uniqueness and extent of the Cambridge and UCL research programmes, where activities range across materials for future systems; higher levels of electronic, photonic and wireless integration; the convergence of wireless and optical communication systems; combined quantum and classical communication systems; the application of THz and optical low-latency connections in data centres; techniques for high capacity access networks; the substitution of many conventional illumination products with photonic light sources and extensive application of photonics in medical diagnostics and personalised medicine. Future systems will increasingly rely on more advanced systems integration, and so the CDT supervisor team includes experts in electronic circuits, wireless systems and enabling software. By drawing these complementary activities together it is proposed to develop an advanced training programme to equip the next generation of very high calibre doctoral students with the required technical expertise, RRI, ES, commercial and business skills to enable the > £24 billion annual turnover UK electronics and photonics manufacturing industry to create the optimised, closely integrated systems of the future. The PES CDT will provide a wide range of learning methods for research students, well beyond that conventionally available, so that they can gain the required skills. In addition to conventional lectures and seminars, for example, there will be bespoke experimental coursework activities, educational retreats, reading clubs, road-mapping activities, RRI and ES studies, secondments to companies and other research laboratories and business and entrepreneurship courses. Students trained by the CDT will be equipped to expand the range of applications into which these technologies are deployed in key sectors of the Digital Futures and wider economy, such as communications, industrial manufacturing, consumer electronics, data processing, defence, energy, engineering, security and medicine.