Book excerpt: This book focuses on the emerging areas of information networking and its applications, presenting the latest innovative research and development techniques from both theoretical and practical perspectives. Today’s networks and information systems are evolving rapidly, and there are new trends and applications in information networking, such as wireless sensor networks, ad hoc networks, peer-to-peer systems, vehicular networks, opportunistic networks, grid and cloud computing, pervasive and ubiquitous computing, multimedia systems, security, multi-agent systems, high-speed networks, and web-based systems. However, since these networks need to be capable of managing the increasing number of users, provide support for different services, guarantee the QoS, and optimize the network resources, a number of research issues and challenges have to be considered in order to provide solutions.