In the evolution of mobile and wireless communications, there can be identified four generations. 4G represents the grand vision of mobile communications, providing mobile users access to advanced applications comparable to those offered by wired networks and, most importantly, maintaining the mobility support which is impossible in wired networks. In this context, this book covers important aspects of the emerging technologies in the heterogeneous next generation network environment with focus on wireless communications and quality of multimedia. The book describes in details several important communication standards, identifies research issues and challenges and presents a survey of the proposed solutions in the literature. The book introduces the newly proposed Dynamic Quality-Oriented Adaptation Scheme (DQOAS), a user-oriented adaptation mechanism that improves user quality of experience (QoE) while also enabling a higher number of simultaneously connected clients to communicate in an IEEE 802.11 network. DQOAS enhances an existing solution, the Quality-Oriented Adaptation Scheme (QOAS) by adding different user QoE expectation levels in the adaptation process.