The key idea of the High Speed Downlink Packet Access (HSDPA) concept is to increase packet data throughput with already known standards like GSM, EDGE, by implementing new techniques of short physical layer frames, Adaptive Modulation and Coding (AMC), fast Hybrid-ARQ and fast scheduling etc. The HSDPA concept facilitates peak data rates exceeding 2 Mbps (theoretically up to and exceeding 14 Mbps), and the cell throughput gain over previous UTRA-FDD releases has been evaluated to be in the order of 50-100% or even more, highly dependent on factors such as the radio environment and the service provision strategy of the network operator. The former part of the book provides the trends of mobile services, drawbacks of 3G systems and the fundamental knowledge of HSDPA. The later part focuses on the basic level simulation of a HSDPA system. So this book provides a good learning background for anybody who wants to know about any wireless system especially HSDPA or starting point to develop a system level simulation.