Final Report Summary - GREENET (An early stage training network in enabling technologies for GREEN radio) The increasing energy consumption and electromagnetic radiation due to the widespread use of mobile communications has been the main motivation for the GREENET project. To that end, a multidisciplinary Training Network of Early Stage Researchers (ESRs) was created in order to conduct top-notch research in energy-related topics, guided by an international team of highly qualified experts from industry and academia. The key objectives targeted within GREENET were defined as follows:Recruit a team of 15 ESRs with the clear and long-term goal to conduct top-notch research and to pursue research excellence at national, European, and international levels.Develop personalized training and career plans that meet the needs and desires of each ESR.Allow the ESRs to understand and address key research challenges on energy efficient GREENET communications, which form mid-to-long term pivotal societal and economic concerns for Europe.Offer to each ESR top-level training and research programs with the twofold objective to reinforce and corroborate their own background, as well as to complement this with active participation in a multidisciplinary network of research scientists.Complement the typical competences of “applied research” with aspects related to project management, intellectual property rights, writing of patents, presentation and communication skills, writing of technical papers, exploitation of technical results and creation of start-up companies, etc.Build a bridge from academia to industry, expanding the ESR career perspectives in either the private or public sectors. The GREENET project has been successfully completed, satisfying its specified objectives in all aspects. First of all, in terms of research, the established research programme, developed within a multidisciplinary and cross-sectorial environment, covered a wide range of communication technologies, enabling the ESRs to provide significant contributions in their respective research areas. More specifically, the most important research findings can be summarized as follows:At the Physical (PHY) layer, novel modulation techniques have been introduced for massive MIMO communications, improving energy efficiency up to 5 times, while reducing up to 98% the computational complexity, compared to state-of-the-art techniques.At the Medium Access Control (MAC) layer, innovative protocols have been proposed and implemented based on the operation of legacy standards (e.g. IEEE 802.11) improving network performance (up to 60% throughput enhancement) and providing up to 360% higher energy efficiency.The use of Analog and Digital Network Coding (NC) techniques to improve the energy efficiency of wireless networks without degrading performance has been investigated, specifically targeted to cooperative networks and Device-to-Device communications. Overall, the proposed NC-aided solutions have achieved up to 40% increase in energy efficiency, ensuring mobility support and network stability.Disruptive infrastructure sharing and Base Station switching off schemes that achieve up to 320% energy savings have been proposed, employing game theoretic tools and considering various network parameters (e.g. MIMO operation, network topology, traffic, etc.) Uplink offloading algorithms and innovative pricing schemes have also been considered. Context-aware cognitive schemes and handover algorithms have been presented and analysed, showing significant energy efficiency gains up to 190% compared to traditional approaches.The importance and the value of the aforementioned research contributions have leveraged the publication of the research outcome in prestigious international journals and conferences, while the work of the ESRs has also been presented in various events (e.g. demo presentations, invited presentations, etc.). The main dissemination activities carried out within the GRENNET project can be summarized as follows:27 publications in high impact factor journals107 presentations in international conferences9 book chapter contributions6 demo presentations42 invited presentation7 other outreach activitiescontribution to standardization activitiesIn addition to the technical achievements, the ESRs had the opportunity to receive outstanding training at both technical and managerial level, thus further advancing their personal and professional growth. In this context, seven seminars were organized during the course of GREENET with the participation of all ESRs. In these seminars, the ESRs also received training on complementary skills related to project management, proposal/patent writing and business planning. In addition, two industrial dissemination days took place during the project, where the ESRs came into contact with important companies in the field, such as Huawei Technology Sweden and Telefonica Spain. Finally, three international conferences (IEEE CAMAD 2012, 2013 and 2014) have been organized with the active support and participation of the GREENET ESRs.The energy efficient solutions proposed within GREENET are expected to have significant socio-economic impact, as energy is a critical resource in the design of wireless networks, given that wireless devices are usually powered by batteries. From the mobile manufacturer’s perspective, the energy consumption problem is becoming a key concern: there exists a continuously growing gap between the energy consumption of emerging radio systems and what can be achieved by battery technology evolution. In fact, without new approaches for energy saving, there is a significant threat that the 4G mobile users will be searching for power outlets rather than network access, thus becoming once again bound to a single location. Therefore it is clear that for the European industry and academia to maintain a competitive stance, it is necessary to investigate effective energy saving mechanisms. Hence, the high quality research and training programme offered within GREENET, has produced a team of new, specialized researchers, with high expertise in the field of green communications. Moreover, GREENET has also addressed one of the key societal concerns at the European stage in terms of “environmentally friendly communications” to globally reduce the electromagnetic radiation levels, as low-power communications can potentially contribute to ameliorate public concerns about health issues related to mobile communication. GREENET results can be exploited by the European Parliament, who, in September 2008, highlighted that the European Health Action Plan should be amended in order to take into account the impact of recent developments in wireless technologies on the health risks posed by emissions from mobile phones.
