This first issue of 2018 is a significant expansion of the number of pages for our journal to continue to reduce the backlog of papers published in the IEEE Xplore as advance posting, but not yet physically included in an issue. This is an extraordinary effort of the IEEE Systems Council to better serve our scientific, technical, and professional community. The first part contains three guest editorials for special issues that appeared in the fourth issue of 2017. By mistake, they were not included with the respective papers. The first guest editorial is the one for the special issue on "Traffic Forensics: Systems, Tools, and Experimentations,” whose Guest Editors are Y.-D. Lin, Y.-C. Lai, G. Kesidis, and A. V. Vasilakos. The second one is for the special issue on "Visual Signal Applications Over Networks," whose GuestEditors are H.-C. Chao, L. Zhou, C. Xu, and P. Lorenz. The third guest editorial is the one for the special issue on "Multimedia Services Provision Over Future Mobile Computing Systems," whose Guest Editors are G. Mastorakis, E. Pallis, C.X. Mavromoustakis, L. Shu, and J.J.P.C. Rodrigues. The second part consists of the special issue on "Communications Technologies and Infrastructures for Smart systems," whose Guest Editors are S. Ullah, W. Pedrycz, G.K. Karagiannidis, H.-C. Chao, A. Gacek, and C. Verikoukis. The third part collects papers on various aspects of complex systems, systems of systems, communications, power, and energy. Papers address various topics encompassing theory, technologies, design methodologies, and applications.