Mobile users are demanding fast and efficient ubiquitous connectivity supporting data applications. This connectivity has to be provided by various different networks and protocols which guarantee that mobile networks function efficiently, performing routing and handoff for mobile users. Hac proposes a comprehensive design for mobile communications including mobile agents, access networks, application protocols, ubiquitous connectivity, routing, and handoff. It covers the entire spectrum of lower and upper layer protocols to evaluate and design modern mobile telecommunications systems. Furthermore, the aspects of modern mobile telecommunications for applications, networking, and transmission are described..