Wireless technologies and applications are becoming one of the fastest growing and most promising areas in recent years. To accommodate data transmission by multiple stations sharing the scarce wireless bandwidth, a medium access control (MAC) protocol plays a crucial role in scheduling packet transmission fairly and efficiently. The emerging wireless networks, such as ad-hoc networks, sensor networks or mesh networks, are mostly multi-hop based and in distributed manner, which brings a lot of problems and challenges in designing fine-tuned MAC protocols tailored for modern wireless network. In this book, the authors give complete and in-depth overviews to the classic medium access control algorithms and the related protocols, as well as their applications in various wireless data networks especially the most successful Wireless Local Area Networks (WLAN). The book consists of three major parts. Part I of this book, including Chapters 1-7, is emphasising on the fundamentals of medium access control algorithms and protocols. Chapter 1 provides an introduction to the wireless networks, such as overview of wireless networks, problems and challenges of the wireless networks, and the classifications of MAC protocols as well as the performance metrics. Chapter 2 introduces important collision resolution algorithms applied in medium access controls, for example, the splitting algorithm and the backoff algorithm. Chapter 3 reviews the hybrid access control algorithms that combine both contention and allocation schemes. A series of important collision avoidance schemes are introduced in Chapters 4-7 respectively, with a specific design goal covered in each chapter. Chapter 4 focuses on the multi-channel MAC protocols for collision avoidance; Chapter 5 introduces the concepts of power control and power management in medium access control and how they can be applied in MAC protocol design; Chapter 6 presents how to provide Quality-of- Service (QoS) to multimedia wireless networks, in either centralised or distributed manner; and Chapter 7 explains how the smart antennas can be applied in the medium access control to provide high channel throughput and low packet collision.