This book gathers selected research papers presented at the Third International Conference on Communication and Intelligent Systems (ICCIS 2021), organized by National institute of Technology, Delhi, India, during December 18-19, 2021. This book presents a collection of state-of-the-art research work involving cutting-edge technologies for communication and intelligent systems. Over the past few years, advances in artificial intelligence and machine learning have sparked new research efforts around the globe, which explore novel ways of developing intelligent systems and smart communication technologies. The book presents single- and multi-disciplinary research on these themes in order to make the latest results available in a single, readily accessible source.