The Internet of Things (IoT), also called as industrial internet, is a global infrastructure of interconnected devices capable of gathering and sharing electronic information. Smart and complex systems like, smart cities, smart grid, smart factories, smart homes, smart buildings and smart cars are based on IoT, and are about installing sensors (RFID, IR, GPS, laser scanners, processors etc.) for everything, and connecting them to the internet through specific protocols for information switch over to achieve intelligent recognition, location, tracking, monitoring and management. IoT applications have emerged with a great potential to change our lives as ubiquitous sensing has enabled new computing and communication paradigms. However, the implementation of efficient, scalable, and reliable IoT systems create many scientific and engineering challenges that call for creative research efforts from academia and industry. New protocols, architectures, and services are in dire need to respond for these challenges. IoT systems also require, high computing, massive storage infrastructure for real-time processing, visualization, and analysis of data. Currently, IoT systems are facing increasing intricacy to handle latency, network bandwidth, scalability, mobility, and energy efficiency. To cope with these challenges, recent trends require interdisciplinary efforts, mathematical modeling and optimization approaches to move this field forward. The motivation of this special issue is to bring together, scholars, professors, researchers, engineers and administrators resorting to the state-of-the-art technologies in order to considerably improve the accessible IoT systems. Therefore, to investigate new developments and disseminate the state-of-the-art research related to IoT, novel contributions containing high-quality original research results as well as review articles for this special issue are invited.