Multi-access mobile devices and overlapping mobile and wireless network deployments have emerged as a reality in the converged telecommunications world. In heterogeneous wireless and mobile environment it is highly important to provide QoS support and seamless handovers between different radio access networks, something that is particularly needed for real-time services. Therefore, this book provides performance analysis of packet scheduling algorithms for cellular mobile networks and for WiMAX. Also, it provides QoS analysis of vertical handover for VoIP and video traffic in a heterogeneous wireless environment. Further, the book proposes improvements for vertical handover decision algorithms regarding the QoS provisioning in mobile and wireless heterogeneous networks, accompanied with numerical analysis and radio access technology selection algorithm. Finally, it gives important discussions and conclusions for improving the QoS in heterogeneous mobile and wireless networks. Hence, this book is useful for all professionals in mobile and wireless networking and to everyone else who is interested in this field of science.