Guest Editorial: IJSCN Special Issue on ASMS/SPSC 2022

This Special Issue of the Wiley International Journal of Satellite Communications and Networking hosts a selection of papers from the 11th Advanced Satellite Multimedia Systems (ASMS) Conference and the 17th Signal Processing for Space Communications (SPSC) Workshop, held virtually on September 6–8, 2022. They were jointly organized by the DLR Institute for Communications and Navigation and JOANNEUM RESEARCH, with the scientific support of the European Space Agency, the University of Bologna, and the Graz University of Technology, under the auspices of “Das Land Steiermark.” The ASMS conference and SPSC workshop have become recognized events for industry and research institutions to exchange up-to-date information about recent advances and emerging technologies in the field of mobile satellite communication systems. The ESA's SPSC workshop dates back to 1988 when pioneering work in digital signal processing for satellite communications was first presented by worldwide authorities in the field. In addition, following the successful path opened by the 2006 edition of ASMS and continued with regular biannual editions, the scope of the conference has been further widened, as the small though important change in its name by replacing the word “mobile” with “multimedia” testifies. This is remarkable not only because the major part of the satcom market belongs to broadcasting and broadband access operators but fundamentally because the convergence of broadcast, mobile, and fixed satellite communications is essential to offer seamless connectivity anywhere at any time, which is recognized as the key element for the successful deployment of future satellite systems. This Issue collects the extended versions of six of the best papers presented at the 2022 ASMS/SPSC joint event. The papers have been selected with the aim of providing an insight in the developments and findings in this exciting field. In the first paper, “Co-Existence of Terrestrial and Non-Terrestrial Networks on Adjacent Frequency Bands,” the authors investigate the deployment options with respect to TN and NTN coexistence, with special focus on spectrum considerations in the form of adjacent frequency bands exploitation. The second paper, “Evaluation of MU-MIMO Digital Beamforming Algorithms in B5G/6G LEO Satellite Systems,” analyzes the potential of MU-MIMO digital beamforming in 5G-enabled LEO satellite systems by showing the research delta with respect to the existing literature and proving the performance superiority through the results collected in extensive simulation campaigns. In the third paper, “Rethinking LEO Constellations Routing with the Unsplittable Multi-Commodity Flows Problem,” the focus is on the design and optimization of routing strategies for LEO satellite constellations by applying the multicommodity flow theoretical framework. The paper discusses the advantages offered by this approach and provides promising results. The fourth paper, “Timing Alignment of Distributed Gateways: Theoretical Analysis and Experimental Demonstration,” is devoted to analyzing the problem of time alignment in the ground segment of satellite networks, implementing a distributed gateways architecture. The paper develops an advanced theoretical framework, later validated through dedicated experimentations. The fifth paper, “5G New Radio Non-Terrestrial Networks Multiuser Precoding,” focuses on the application of MU-precoding solution in the context of 5G-enabled NTN architectures, by analyzing the use of precoding over 5G NR waveforms. The provided results are insightful and shed light on the potential of such a technique for real-world implementation. Last but not least, the sixth paper, “Contribution of NOMA Signalling to Practical Multibeam Satellite Deployments,” proposes the application of NOMA-based signaling to satellite systems by considering realistic configurations and carrying out simulations accordingly. The collected results prove the validity and potential of the designed NOMA solution. In closing, the Guest Editors would like to thank all individuals and organizations that made this issue possible, including the ASMS/SPSC 2022 Technical and Scientific Committees, all anonymous reviewers, and all authors. In particular, we are grateful to Prof. Barry Evans, the Editor in Chief of the International Journal on Satellite Communications and Networking, for kindly inviting us once more to conduct this editorial process, as already done for past events. The authors declare no conflicts of interest. The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions. Tomaso de Cola received the “Laurea” degree (with honors) in telecommunication engineering in 2001, the Qualification degree as a Professional Engineer in 2002, and the PhD degree in Electronic and Computer Engineering, Robotics, and Telecommunications in 2010 from the University of Genoa, Italy. Since 2008, he has been with the German Aerospace Centre (DLR), where he is leading the Integrated Satellite Systems group in the Institute of Communications and Navigation. He has been involved in different European Projects focusing on various aspects of DVB standards, CCSDS protocols, and testbed design, and he is a coauthor of more than 100 papers, including international conferences and journals. He was the chair of the Satellite and Space Communications (SSC) technical committee within ComSoc and of the SatCom working group within the ETP NetworldEurope platform. Currently, he serves as area director of the Space-Internetworking Services (SIS) within the CCSDS standardization body. He has been involved in many editorial initiatives in IEEE journals and magazines as a guest and associate editor. Alessandro Guidotti (Member, IEEE) received the master's degree (magna cum laude) in telecommunications engineering and the PhD degree in electronics, computer science, and telecommunications from the University of Bologna, Italy, in 2008 and 2012, respectively. From 2009 to 2011, he represented the Italian Administration within CEPT SE43. From 2014 to 2021, he was a Research Associate with the Department of Electrical, Electronic, and Information Engineering “Guglielmo Marconi,” University of Bologna. Since 2021, he has been a Senior Researcher with Consorzio Interuniversitario Delle Telecomunicazioni (CNIT). He is active in national and international research projects on wireless and satellite communication systems in several ESA- and EC-funded projects. His research interests include wireless communication systems, spectrum management, cognitive radios, interference management, 5G, and machine learning. He is a member of the IEEE AESS “Glue Technologies for Space Systems” Technical Panel. He has been serving as the TPC and Publication Co-Chair at the ASMS/SPSC Conference since 2018. He was the Workshop Co-Chair of the 2023 IEEE WiSEE Conference. He is the CNIT Representative for the ESA NTN Forum. Stefano Cioni received the Dr. Ing. degree in telecommunication engineering and the PhD degree from the University of Bologna, Italy, in 1998 and 2002, respectively. Since 2002, he has been a Senior Researcher at the Advanced Research Center for Electronic Systems (ARCES), University of Bologna. In 2010, he joined the European Space Agency, Noordwijk, the Netherlands, where he is currently a Telecommunication Systems Engineer within the Radio Frequency Systems, Payload and Technology Division. Since September 2016, he has been attending the 3GPP RAN plenary and RAN-WG1 meetings, with the specific interest to support non-terrestrial network (NTN) aspects and to facilitate the 5G terrestrial/satellite networks integration. He has coauthored more than 100 papers and scientific conference contributions. His research activities are mainly focused on the next-generation broadcast/broadband satellite systems for fixed and mobile satellite services. His interests include efficient digital coding and modulation techniques, adaptive interference mitigation algorithms in multiple access systems, synchronization techniques, MIMO and OFDM systems, and iterative decoding techniques joint to channel parameter estimation. He has been selected as a recipient of the IEEE ComSoc Satellite and Space Communications Technical Recognition Award 2020. He is a corecipient of the Best Paper Award at IEEE ICT 2001 and at IEEE ASMS/SPSC 2012.