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Green Wireless Internet Technology

2014; Institution of Engineering and Technology; Volume: 8; Issue: 6 Linguagem: Inglês

10.1049/iet-smt.2014.0348

1751-8830

Raed A. Abd‐Alhameed, Jonathan Rodrı́guez, B.A.L. Gwandu, P.S. Excell, Mohammad Ngala, Abubakar Sadiq Hussaini,

Green IT and Sustainability

In the future, communications will be pervasive in nature allowing users to access at the ‘touch of button’ any service, at any time, on any device. This will require future devices to go beyond the rigid specification we have today, to be reconfigurable in nature in order dialogue with a whole host wireless networking, even including the eventual 5G communication portal. However, any new design framework shouldn't only be about reconfiguration. Energy efficiency or green communications is now adopting a prominent role at the forefront of system design. On one hand, devices are increasingly becoming power hungry as more sophisticated applications and features, like navigations tools, are drawing more power from your handset device. Battery technology has not advanced sufficiently to cope with these energy demands, leading towards very restrictive battery lifetime and standby time, and the situation is likely to get worse as devices become smaller and always ‘connected’. In fact, an energy trap is starting to emerge where users could be bound to the nearest available power sockets instead of enjoying the full benefits of user mobility, that 5G and beyond is likely to offer. On the hand, the energy bill accounts for the largest operational expense for mobile operators, which is likely to proliferate. Analysts are predicting that mobile traffic is set to explode with about every physical object we see (e.g., clothes, cars, trains, etc.) to form part of the Internet of things. It is predicted that a 1000x increase in data services can be expected within the next decade, urging operators to seek new solutions on how to deploy, and manage their networks for improving coverage, boosting their network's capacity, and above to all to keep the energy bill low through energy efficient design. Energy efficiency is a design driver that has had much attention from political strands. Recently, information and communication technology accounted for 3% and 2% of the global power consumption and global CO2 emissions, respectively, a worrying statistic that is likely to take an upwards trends with market demand always on the rise. To take a proactive stance towards mitigating this alarming trend, the vision of Europe 2020 is to become a smart, sustainable and inclusive economy, and as part of these priorities the EU have set forth the 20:20:20 targets, whereby greenhouse gas emissions and energy consumption should be reduced by 20% while energy from renewables should be increased by 20%, respectively. The political drive in synergy with the need for reduced operational expenditure has placed green wireless networking at the forefront, requiring solutions that are not only spectrally efficient, but also energy efficient, in nature. The approach towards energy efficient design will be challenging and will require concrete solutions targeting all layers of the protocol stack, and low complexity RF while maintaining the required Quality of Experience (QoE). There is a need for networks and user terminals to take a more holistic design approach towards green communications, right from radio operation and functionality, up to the implementation. Investigating this line of research, the School of Engineering and Informatics at Bradford University (UK); 4TELL Research Group at the Instituto de Telecomunicações, (Aveiro-Portugal); School of Engineering & Engineering Technology at the Modibbo Adama University of Technology (Yola-Nigeria); School of Information Technology & Computing, American University of Nigeria; and the Commonwealth ITU group (UK) are all playing leading roles, and provided the inspiration for this IET Special Issue on Green Wireless Internet Technology. We aim to target high quality research and practical case studies in the very essence of green wireless networking and reconfigurable transceivers to provide design requirement and recommendations for the key components for tomorrow's ICT networks that will support a whole host of future services, internet of things (IoT) and e-applications with minimised energy cost. The scientific works presented here provide a step further toward overcoming the so called energy trap, which is seen by many as the next stumbling block in the migration towards 5G systems. We present twelve leading works that will allow the IET readership to go beyond state-of-the-art on these topics, and perhaps establish new bridges towards further innovation in green communications. The first article by Alimenti et al. is entitled ‘24-GHz Patch Antenna Array on Cellulose-Based Materials for Green Wireless Internet Applications’. The authors exploit the use of cellulose-based paper substrate to fabricate patch array antenna at 24GHz. They also adopt microstrip circuitry and exploit copper adhesive laminate that is shaped by a photo-lithographic process and transferred to the hosting substrate using a sacrificial layer. The proposed design shows the feasibility of low-cost antenna systems for green wireless internet technology and applications up to the boundary between microwaves and millimetre-waves. The contribution by Chen et al., entitled ‘Analysis of Collaborative Spectrum Sensing With BPSK Signal Power Estimation Errors’, proposes novel iterative and non-iterative blind estimation methods for binary phase shift keying modulated primary user signal power using the maximum likelihood principle for collaborative spectrum sensing. The authors explore the effect of the primary user traffic on these methods. The proposed blind estimation methods offer an excellent trade-off between reliability and complexity. ‘Compact and Closely Spaced Tuneable Printed F-Slot MIMO Antenna System for Mobile and Wireless Applications with Efficient Diversity’, by Elfergani et al., proposes a miniaturised tunable two-antenna MIMO system composed of printed F-slot shapes that is to operate in the GPS, PCS, DCS and UMTS bands. The approach makes use of two sets of antennas, loaded with varactors to simultaneously achieve miniaturisation and tunability. To assess its effectiveness, the channel capacity of the proposed antenna is investigated and found to be close to that of an un-correlated system with efficient diversity in which the mutual coupling across the full bandwidth was better than −13 dB. The proposed antennas can be a promising solution for adaptive MIMO systems in handheld devices. A fundamental theme in this Special Issue considers reconfigurability, a design attribute that will accommodate several radio technologies. To address this topic, the contribution by Cheng et al. entitled ‘A Practical Realisation of a Novel Software Defined Radio Based Aeronautical Communications System’ considers an innovative architectural design, software implementation, validation and flight trial results for an aeronautical communications system developed to accommodate several radio technologies. This can drastically reduce the size, weight and cost in avionics with respect to current radio systems implemented as standalone equipment. In addition, the modular approach ensures the possibility of dynamically reconfiguring each radio element to operate on a specific type of radio link. A radio resource management (RRM) framework is developed in the Integrated Modular Radio (IMR), consisting of a communication manager for the resource allocation and management of the different radio links and a radio adaptation manager to ensure protocol convergence through the Internet Protocol (IP). Olwal et al. contribute the work entitled ‘Bio-inspired Energy and Channel Management in Distributed Wireless Multi-Radio Networks’, which proposes a biological behaviour-based network resource management method in order to address the inefficient energy and frequency channel utilisation problems. The research is inspired by the well-established optimal foraging theory, whereby a solitary biological forager in a random ecosystem makes optimal decisions that maximise its own nutrients consumption, survival probability and lifetime, while minimising possible risks associated with its own behaviour. The paper has applied this natural principle and developed a Bio-inspired Energy and Channel (BEACH) management method. The BEACH method is aimed at achieving both efficient communication energy and frequency channel utilisation in the considered distributed wireless multi-radio network. The efficiency of the developed BEACH method has been extensively validated through computer simulations and was shown to yield improved energy-efficiency and throughput performance. The article ‘Cooperative Transmission Schemes for Energy Efficient Collaborative Wireless Sensor Networks’, by Naeem et al., investigates collaborative wireless sensor networks. Energy conservation is one of the prime concerns that leads the researcher to investigate collaborative wireless sensor networks with some application specific challenges. Such challenges include combining distributed data synchronously, performing power aware signal processing, defining communication methods that can provide progressive accuracy, and optimising processing and communication for signal transmission. A cooperative resource selection and transmission scheme is proposed to improve the performance of collaborative wireless sensor networks in terms of maintaining link reliability. A measure of Channel Quality Index (CQI) is also proposed to obtain dynamic adaptivity and to optimise resource usage within wireless sensor networks according to environment conditions. Based on CQI, a subset of nodes is proposed to be chosen to perform cooperative transmission by exploiting collaboration between wireless sensing nodes. As part of the proposed cooperative nature of transmission, the recently proposed transmit-receive antenna selection scheme and lattice reduction algorithm have also been considered. It is assumed that channel state information (CSI) is estimated at the receiver and also there is a feedback link between the wireless sensing nodes and the fusion centre receiver. From the simulation results it is observed that, for 99.99% detection reliability, the proposed adaptive transmission scheme and proposed hybrid scheme consume only 15% and 18% of energy respectively, compared to the conventional cooperative transmission. The next contribution, by Antonopoulos et al. and entitled ‘ANC-aided Game Theoretic MAC Protocol for Energy Efficient Data Dissemination’, targets a novel medium access scheme based on Analogue Network Coding (ANC) for data dissemination in wireless networks. The authors propose a Medium Access Control (MAC) protocol that exploits to the maximum the recent advances in Network Coding (NC) domain to enhance the system performance. In particular, ZigZag decoding techniques are applied to resolve the data packet collisions, while Random Linear NC (RLNC) is employed to eliminate the need of exchanging control packets. The proposed protocol, evaluated by both analytical and simulation results, is proven to improve the energy efficiency in the network without compromising the provided Quality of Service. The contribution by Ajibesin et al. is on ‘DEA Envelopment with Slacks Model for Energy Efficient Multicast Over Coded Packet Wireless Networks’. The authors propose novel approaches that are based on Data Envelopment Analysis (DEA) to further optimise energy consumption in wireless multicast networks. They develop the input-oriented VRS envelopment with slacks models for energy efficiency in ad hoc wireless multicast networks. The authors explored the random linear network coding (RLNC) based on simulation approach and compared the results with the input-oriented VRS DEA envelopment with slacks approach. The results show that the DEA approach substantially saves energy compared with the RLNC. Furthermore, they show that DEA method has the ability to identify which ad hoc network is inefficient and project them onto the efficient frontier. The next article, ‘Energy Efficient Transmission Techniques for Wireless Sensor Networks’ by Haleem et al., studies power versus rate performance of a class of transmission techniques. The study arises in the context of a wireless sensor network in which multiple nodes, equipped with single or multiple antennas, cooperatively send simultaneous and distinct signals to multiple receiving nodes that are each equipped with a single receiving antenna. The criterion in deriving the techniques is to eliminate or minimise the mutual interference so as to maximise received signal to interference plus noise ratio (SINR). It is shown that, for low bit rates, time-shared transmission can achieve the performance of the optimal power shared technique operating in spatially uncoupled (ideal) channels. As the bit rate increases, time-shared transmission becomes suboptimal. In this context, Best Linear Optimisation (BLO), Dirty Paper Coding (DPC) and Zero Forcing (ZF) are promising. The work of Fouad et al., entitled ‘Adaptive Control of Solar Tracking System’, presents an adaptive controller of a solar tracking system. The authors studied two tracker systems based on open- and closed loop control strategies. The designed control system objective is to keep the tracker perpendicular to sunlight at all times during the day and eliminate modelling errors such as sun position data deviations, friction and environmental changes. System performance is verified through computer simulation, where the controller corrected for modelling errors and date changes from the date used for algorithm design. Ghani et al. contribute the work entitled ‘A Step Forward to Map Fully Parallel Energy Efficient Cortical Columns on Field Programmable Gate Arrays (FPGAs)’. This paper proposed an area-efficient architecture at the system level and benchmarked with a speech recognition application. The authors present energy and area-efficient hardware architectures to fully map parallel cortical columns on reconfigurable platform – Field Programmable Gate Arrays (FPGAs). Due to the spatio-temporal nature of spiking neurons, it is more suitable to map such architectures on FPGAs where signals can be represented in binary form and communication can be performed through the use of spikes. The viability of implementing multiple recurrent neural reservoirs is demonstrated with a novel multiplier-less reconfigurable architecture, and a design strategy is devised for its implementation. The final article, by Behjati et al. and entitled ‘Self-Organising Comprehensive Handover Strategy for Multi-Tier LTE-Advanced Heterogeneous Networks’, proposes the comprehensive handover algorithm. The authors investigate handover between the different layers of a heterogeneous LTE-Advanced system as a critical attribute to plan the best way of interactive coordination within the network for the proposed HetNet. The algorithm takes account of multiple factors in both handover sensing and decision stages, based on signal power reception, resource availability and handover optimisation, as well as prioritisation among macro and femto stations, in order to obtain maximum signal quality while avoiding unnecessary handovers. Overall, the papers presented here represent a cross-section of leading-edge work across a range of topics relevant to the theme of the Special Issue, drawn from a broad spread of international contributors and giving clear indicators of the way in which work to address the green communications agenda is progressing. We would like to thank all authors who submitted manuscripts to this Special Issue and also the reviewers that assisted the guest editors to select the best articles for publication. Our gratitude also extends to the School of Engineering and Informatics, University of Bradford, UK; 4TELL Research Group at the Instituto de Telecomunicações, Aveiro, Portugal; School of Engineering & Engineering Technology, Modibbo Adama University of Technology, Yola, Nigeria; School of Information Technology & Computing, American University of Nigeria, and the Commonwealth ITU group, UK, that provided the launch pad for this Special Issue. Prof Raed Abd-Alhameed is Professor of Electromagnetic and Radio Frequency Engineering at the University of Bradford, UK. He has many years of research experience in the areas of radio frequency, signal processing, propagations, antennas and electromagnetic computational techniques, and has published over 400 academic journal and conference papers. In addition, he is co-authors of three books and several book chapters. At the present he is the leader of Radio Frequency, Propagation, Sensor Design and Signal Processing, in addition to leading the Communications research group for years within the School of Engineering and Informatics, Bradford University, UK. He is Principal Investigator for several funded applications to EPSRCs and leader of several successful Knowledge Transfer Programmes such as with Pace plc, YW plc, ITEG ltd, Datong plc, Emkay ltd, and Two limited. His interests are in computational methods and optimisations, wireless and Mobile communications, sensor design, EMC, beam steering antennas, energy efficient Pas and RF predistorter design applications. He is a Fellow of the Institution of Engineering and Technology, Fellow of Higher Education Academy and a Chartered Engineer. Jonathan Rodriguez, CEng, SMIEEE received his Masters degree in Electronic and Electrical Engineering and Ph.D in Mobile Communications from the University of Surrey (UK), in 1998 and 2004 respectively. In 2002, he became a Research Fellow at the Centre for Communication Systems Research and was responsible for coordinating Surrey involvement in European research projects under framework 5 and 6. Since 2005, he is a Senior Researcher at the Instituto de Telecomunicaçoes (Portugal), where he founded the 4TELL Wireless Communication Research Group in 2008. The 4TELL group currently constitutes 30 researchers with a Project portfolio that includes 10 ongoing European collaborative research projects. He was the project coordinator of FP7-C2POWER, CELTIC LOOP, CELTIC GREEN-T and the technical manager of the FP7 COGEU project, and currently acts as coordinator of several national and international projects. He is author of more than 270 scientific publications, served as general chair for several prestigious conferences and workshops, and has carried out consultancy for major manufacturers participating in DVB-T/H and HS-UPA standardisation. Bashir Gwandu, PhD, MBA, CEng FIET: Dr Gwandu has acted as the Chairman of Commonwealth ITU Group (CIG), was the Executive Commissioner (Technical Services) of the Nigerian Communications Commission (NCC), was the Chairman of Radiocommunications Advisory Group of the ITU (the RAG), and also the Vice Chairman of ITU-R Joint Task Group 4567 (JTG-4567). Dr Gwandu has served as the Vice-Chair of Committee 4 of the ITU Radiocommunications Assembly 2012 (RA-12). He became the Chairman of the CIG in March 2012. He was the Acting CEO of the Nigerian Telecoms Regulatory body, the NCC, from June to July 2010. After receiving his BSc in Physics from UsmanDanfodiyo University, Sokoto and an MSc in Applied Physics from the University of Jos, in addition to a brief Engineering service at the Tactical Air-command, Makurdi and lecturing at UsmanDanfodiyo University, Sokoto, he proceeded to the United Kingdom where he attended MSc Courses in Power Electronics and Drives and MSc courses in Communications Engineering at University of Birmingham. He further obtained an MPhil degree in Electrical/Electronic Engineering, also from the University of Birmingham. He returned briefly to Usman Danfodiyo University, Sokoto to lecture before going back to the UK to study for a PhD in Electronic/Electrical Engineering at Aston University. He then subsequently undertook an MBA Finance course at the Birmingham Business School. Dr Bashir Gwandu is a regular invited speaker at many International Telecom and Telecom Investment Conferences, and has represented Nigeria in many Forums on Telecoms Regulations. He was, until recently, on the Board of the NigComSat Ltd, and the Board of Digital Bridge Institute. Internationally, he provided leadership and spoke for the African team on Agenda Item 1.4 of ITU WRC-2007, which was the turning point for Africa on ITU WRC matters. He also led the successful pursuit of the Allocation of 700MHz band to Region 1 during WRC 2012. Prof Peter Excell joined Glyndwr University in 2007. He was previously Associate Dean for Research in the School of Informatics at the University of Bradford, UK, where he had worked since 1971. He obtained a BSc in Engineering Science from Reading University in 1970 and was awarded his PhD from Bradford University in 1980 for research in electromagnetic hazards. His long-standing research interests have been in the applications and computation of high-frequency electromagnetic fields. These have led to numerous research grants, contracts and patents in the areas of antennas, electromagnetic hazards, electromagnetic compatibility and field computation. His principal recent work has been in the computation and measurement of electromagnetic fields due to mobile communications terminals. This led to significant advances in the development of the hybrid field computation method and novel designs for mobile communications antennas. His current work includes studies of advanced methods for electromagnetic field computation (including the use of high performance computing), the effect of electromagnetic fields on biological cells, advanced antenna designs for mobile communications, and consideration of usage scenarios for future mobile communications devices. He is a Fellow of the Institution of Engineering & Technology, the British Computer Society and the Higher Education Academy, a Chartered Engineer and Chartered IT Professional, a Senior Member of the Institute of Electronics and Electrical Engineers, an Associate Fellow of the Remote Sensing and Photogrammetry Society, and a member of the Association for Computing Machinery, the Applied Computational Electromagnetics Society, and the Bioelectromagnetics Society. Mohammad J Ngala PhD, MSc, PGCE had all his post-secondary education in England and France; he received his MSc degree in Transport from City University, London in 1986 and completed his PhD in 1991 from the School of Engineering & Informatics, University of Bradford. He is presently a Director at Heaton Education, an Associate Professor and member of the University Senate at the School of Engineering & Engineering Technology, Modibbo Adama University of Technology, Yola, Yobe State University, Damaturu and the National Open University of Nigeria, Lagos Nigeria where he acts as the Coordinator for International Academic Partnerships. His experiences and exposure spans both commercial activities and academia; such as the provision of a 30 MW power station using private capital in a city of 2 million people under Public Private Partnerships. On the other hand, his academic experience entails teaching in various colleges in West Yorkshire, England. He has had more than 12 years of hands on working experience in Telecommunications in the UK and Europe and has worked for British Telecom, BTCellnet, and Telefonica of Spain. Abubakar Sadiq Hussaini, MSc, PhD: Head of Programmes/Director at Commonwealth ITU Group (CIG), actively participating in the ITU activities of the Radiocommunication, Telecommunication Standardisation and the Telecommunication Development Sections. He is Senior Researcher and Project Development Manager with the 4TELL research group at Instituto de Telecomunicações, Aveiro, Portugal, Visiting Researcher at University of Bradford, UK, Visiting Assistant Professor at American University of Nigeria, Yola, and Visiting Assistant Professor at Modibbo Adama University of Technology, Yola, Nigeria. He was Visiting Researcher at University of Aegean (UA), Greece, He was Microwave Radio Transmission Operations & Maintenance Senior Engineer with Nigerian Telecommunication Limited (NITEL), Abuja, Nigeria for 10 years. He was on the Senate Committee of the University of Bradford, UK, received his MSc in Radio Frequency Communication Engineering from the University of Bradford (UK) in 2007 and his PhD in Telecommunications Engineering from University of Bradford, UK. He is a member of IEEE, IET and Optical Society of America. He has contributed to numerous publications and is involved in European and CELTIC research projects. His research interests include Radio Frequency System Design and High-Performance RF-MEMS Tunable Filters, with specific emphasis on energy efficiency and linearity, and his achievements comprise participation in the design of energy efficient Power Amplifier at 3.5 GHz (Mobile WiMAX Frequency); the design of High-Performance RF-MEMS Tunable Filters with tuning range from GSM 1.8 GHZ to LTE 2.6 GHz; the design and development of a ‘Radio over Fiber’ optical transmitter and an Optical Receiver (1550 nm Wavelength) in which the frequency limitations of quantum well lasers in direct RF to Light transponding was investigated. He successfully attained several European projects; among which are MOBILIA (2009–2011), ARTEMOS (2011–2014) & THINGS2DO (2014–2018). He has participated actively in events, conferences and seminars organised by the Information Society Technology (IST) research program, Institute of Electrical and Electronics Engineers (IEEE), Institute of Engineering and Technology (IET), and European Nano Electronics Forum. He also participated in several annual European project reviews. His collective role is to defend the project objectives and results to a panel of examiners that are considered European experts in their respective technical fields. He served as a workshop organiser and a workshop chair. He is a TPC member and reviewer for many international conferences and journals.