Emerging applications, services and engineering for [Guest Editorial]

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GUEST EDITORIAL

EMERGING APPLICATIONS, SERVICES AND ENGINEERING FOR CELLULAR COGNITIVE SYSTEMS

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Muhammad Zeeshan Shakir

Octavia A. Dobre

Muhammad Ali Imran

Apostolos Papathanassiou

Zhongshan Zhang

Athanasios V. Vasilakos

Honggang Wang

Hiroshi Harada

he rapid advancements in wireless communications are expected to increase the demand for radio spectrum resources by orders of magnitude during the next decade. This problem must be addressed using technology and regulatory innovations for significant improvements in spectrum utilization in cellular networks. Emerging cognitive radio technology has been identified as a high-impact disruptive innovation that could provide solutions to the cellular traffic congestion problems and exploit the underutilized spectral resources to pave an application-driven path toward the next generation of cellular technology. Along with the advent of the 5G era in telecommunications systems, new emerging applications, services, and engineering (EASE) frameworks are now required to be facilitated with the advances in cognitive cellular systems (CCSs) to jointly address the socio-scientific challenges of global significance and catalyze the diversification of the world economy. This Feature Topic is a new addition in the scientific community to introduce the EASE framework. The goal of this Feature Topic is to showcase contributions from experts to further identify and present recent results and technical challenges related to new applications, and engineering, as well as the convergence of associated infrastructure for future implementation in CCS. The Feature Topic received a large number of submissions, and it has been a challenging task to select the best 32

and most relevant papers. We have selected the top 15 research articles out of 47 submitted articles. The accepted articles are being published as two parts in IEEE Communications Magazine. Part 1 of the Feature Topic presents the landscape of future spectrum requirements by exploiting emerging frameworks including spectrum aggregation, resource management and spectrum harvesting techniques to facilitate the ever-increasing demand for ubiquitous connectivity over the limited spectrum. This part also covers business models and network economic issues associated with the implementation of CCSs. The first two articles are related to dynamic spectrum aggregation and spectrum access in future CCSs. The article by Hanna et al. presents potential methods for dynamic spectrum aggregation, and emphasizes the opportunities and issues for 5G communications in CCSs. The article focuses on two multicarrier techniques, enhanced non-contiguous orthogonal frequency-division multiplexing and non-contiguous filter-bank-based multicarrier. Issues beyond traditional spectrum access and shaping are considered, related to the aggregation dynamics, nonlinear effects in the transmission chain, as well as receiver synchronization and performance. Pros and cons are illustrated, regarding such issues as complexity, the need for lower peak-to-average power ratio and out-of-band power reduc-

IEEE Communications Magazine • May 2015

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GUEST EDITORIAL tion, as well as interference-robust reception and synchronization. Additional directions of research are pointed out, such as increasing the flexibility of the RF front-end design to operate in multiple bands and handling the aggregated interference resulting from multiple cognitive radio transmissions. The article by Guizani et al. looks at the scalability challenge for dynamic spectrum access systems. To this end, the article presents viable distributed methods that are scalable to a very large number of nodes. The need for information exchange between distributed decision making nodes introduces delay, and this article summarizes how game theoretic techniques, learning (e.g., Q-learning), and filtering (e.g., particle filtering) approaches have aimed to achieve distributed cognitive solutions with minimal information exchange. The authors provide a comparison of learning and particle-filtering approaches for distributed dynamic spectrum allocation methods and show that the particle-filtering method achieves better throughput performance in fast changing dynamic environments. The third article, by Saad et al., presents a matching theory-based framework for dynamic resource allocation and management in emerging wireless networks. Centralized optimization techniques and game theoretic approaches have reached their limitations in solving the dynamic resource allocation problem in emerging highly dense wireless networks. Therefore, the primary objective of this article is to introduce the new engineering-oriented classes of matching theory, and provide robust and stable optimal treatment in the context of resource allocation problems for various heterogeneous-type networking environments. This interesting tutorial-oriented exposure of this Nobel Prize winning framework could potentially contribute to the further theoretical analysis of future wireless networks and their implementation. The fourth article, by Zhang et al., investigates interesting potential solutions for solving the challenge of spectrum scarcity. The authors propose an integrated cooperative framework for cooperative spectrum harvesting. They consider cooperation between the primary and secondary nodes as well as among a cluster of nodes in order to identify and harvest spectrum opportunities more efficiently. Their results show that significant improvements in spectrum efficiency and expected available time can be achieved using the proposed framework. An interesting aspect of the framework is the model to exchange credits between the cooperating nodes, which can potentially develop into a more practical business model in future CCSs. The impact of this research can be far reaching if extended to explore the potential of spectrum aggregation, utilization of narrow spectrum white spaces, and coexistence of licensed and license-exempt spectra in cellular scenarios of future generations. In the fifth article, Mustonen et al. give a comprehensive review of the European licensed shared access (LSA) concept [4] spectrum sharing between a mobile network operator (MNO) and an incumbent spectrum user. The article views this novel application area of cognitive radio from the MNO point of view and provides valuable system design criteria that need to be considered by the MNO in order to succeed in utilizing the LSA opportunity as an additional

IEEE Communications Magazine • May 2015

means for meeting the constantly growing mobile traffic demand. The article is also valuable not only because it describes existing LTE/LTE-Advanced technologies, which can appear useful in introducing LSA in a cellular network, but also because it introduces the LSA management unit required to be implemented on top of the existing cellular network for enabling and optimizing LSA. Network economics are the soul of CCSs, and therefore it is essential to carefully study and plan these aspects for CCSs to strive. It has been realized that the network architecture, algorithms, and protocols cannot simply be designed without considering the socio-economic aspects involved. The sixth article, by Jiang et al., presents both the simultaneous and sequential behaviors in CCSs, with scenarios and examples to illustrate possible solutions. The authors highlight the network economic issues in CCSs from the perspectives of game theoretic modeling and mechanism design to reveal the fundamental problems and corresponding enabling techniques. The goal of this article is to provide an overview to understand the motivation, problem formulation, methodology, and solutions of the economic issues in CCSs. Business modeling for database-assisted TV white space networks is regarded as a promising paradigm of dynamic spectrum sharing and can be exploited further to substantially alleviate the spectrum scarcity in future CCS. In the last article, Luo et al. present the concept of databaseassisted TV white space network architecture where unlicensed devices obtain available spectrum via querying a certified geolocation database instead of performing traditional spectrum sensing. Two types of business models (i.e., spectrum market and information market) are discussed. The performance of both models is also evaluated, indicating that both the database operator’s profit and the total network profit can be significantly improved by employing properly designed trading mechanisms. Before closing Part 1 of this Feature Topic, which mainly covers emerging services and engineering frameworks in CCSs, we would like to thank all submitting authors for considering this Feature Topic as a potential venue for their research work, the reviewers for their highquality evaluation, and the editorial/publishing team of IEEE Communication Magazine for their collaboration. We will be back with the remaining articles as Part 2 of this Feature Topic in the July 2015 issue, which will mainly cover emerging applications in CCS.

BIOGRAPHIES MUHAMMAD ZEESHAN SHAKIR ([email protected]) has been an assistant research scientist at Texas A&M University at Qatar in Doha, Qatar, since July 2012. He received his Ph.D. in electronic and electrical engineering from the University of Strathclyde, Glasgow, United Kingdom, in 2010. From January 2006 to September 2009, he was the joint recipient of an industrial research fund and a prestigious overseas research scholarship by the University of Strathclyde. His research interests include design and deployment of diverse wireless communication systems, including hyper-dense heterogeneous small cell networks. He has published more than 75 technical journal and conference papers, and has contributed to six books, all in reputable venues. He is co-author of two research monographs. Most of his research has been sponsored by Qatar National Research Fund and national industrial partners. He has served as a lead Guest Editor for IEEE Communication Magazine and IEEE Wireless Communications. He has served as co-chair of several special sessions/workshops and symposia at flagship conferences, such as IEEE ICC and GlobalSIP.

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GUEST EDITORIAL OCTAVIA A. DOBRE is an associate professor with Memorial University, Canada. In 2000 she was the recipient of a Royal Society scholarship in the United Kingdom, and in 2001 she held a Fulbright Fellowship in the United States. Her research interests include cognitive radio systems, spectrum sensing techniques, transceiver optimization algorithms, and dynamic spectrum access. She has published over 130 journal and conference papers in these areas. She is a Senior Editor for IEEE Communications Letters, and has served as Editor and Guest Editor for other prestigious IEEE journals. She has been the Co-Chair of technical symposia at flagship conferences such as IEEE ICC and IEEE GLOBECOM. MUHAMMAD ALI IMRAN is a reader (associate professor) in the Institute for Communication Systems, University of Surrey, United Kingdom. He is leading the physical layer work area for 5G innovation center and is curriculum design leader for the Engineering for Health center in Surrey. He has successfully led international projects encompassing the areas of energy efficiency, fundamental performance limits, sensor networks, and self-organizing cellular networks. He has supervised 20 successful Ph.D. graduates and published more than 150 peer-reviewed research papers. He is an Associate Editor for IEEE Communications Letters and the IET Communications Journal, and has served as a Guest Editor for other prestigious IEEE/IET journals. APOSTOLOS (TOLIS) PAPATHANASSIOU is responsible for LTE PHY standardization and 5G technology development activities in the Next Generation and Standards (NGS) division of Intel’s Communication and Devices Group (iCDG). He has more than 50 scientific contributions to international journals, conferences, and books, and more than 100 contributions to wireless standardization bodies such as 3GPP and IEEE 802.11/802.16. Previously at Intel, he led multiple standardization efforts in ITU-R and IEEE/WiMAX Forum. Before joining Intel, he worked on multiple-antenna PHY techniques and algorithms for 3G, WiFi, and satellite systems. Z HONGSHAN Z HANG received his Ph.D. degree in electrical engineering in 2004 from Beijing University of Posts and Telecommunications. From

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February 2006 to March 2009, he was at the University of Alberta, Canada, as a postdoctoral fellow. He has also worked in DoCoMo Beijing Laboratories, Alcatel-Lucent Shanghai-Bell, and NEC China Laboratories as a researcher. He is currently a professor of the University of Science and Technology Beijing. His main research interests include self-organized networking, cognitive radio, and cooperative communications. ATHANASIOS V. VASILAKOS is currently a professor with Kuwait University. He has served or is serving as an Editor for many technical journals, such as IEEE Transactions on Network and Service Management; IEEE Transactions on Information Forensics and Security; IEEE Transactions on Systems, Man, And Cybernetics—Part B: Cybernetics; IEEE Transactions on Information Technology in Biomedicine; IEEE Transactions on Computers; IEEE Transactions on Cloud Computing; ACM Transactions on Autonomous and Adaptive Systems; and the IEEE Journal on Selected Areas in Communications. He is also General Chair of the Council of Computing of the European Alliances for Innovation (www.eai.eu). H ONGGANG W ANG is an assistant professor at the University of Massachusetts Dartmouth. His research interests include wireless health, body area networks, cybersecurity, mobile multimedia and cloud, wireless networks and cyberphysical systems, and big data in mHealth. He serves as an Associate Editor of IEEE Transactions on Big Data, the IEEE IoT (Internet of Things) Journal, and the IEEE Access Journal, and an Associate Technical Editor of IEEE Communications Magazine. HIROSHI HARADA joined the Communications Research Laboratory in 1995, part of Japan’s Ministry of Posts and Communications (currently National Institute of Information and Communication Technology, NICT). Since 1995, he has researched software defined radio, cognitive radio, dynamic spectrum access network, and broadband wireless access systems on the microwave and millimeter-wave band. Currently he is director of the Smart Wireless Laboratory at NICT and has been a visiting professor of the University of Electro-Communications, Tokyo, Japan, since 2005.

IEEE Communications Magazine • May 2015