The book presents Fog networking (which can be simplified as cloud at the edge) for 5G and Internet of things (IoT) networks. Important aspects of fog computing, including measurement, resource polling, security and privacy, will also be discussed. The book chapters are designed to motivate a transition from the current cloud architectures to the Fog (Chapter 1), and the necessary architectural components to support such a transition (Chapters 2-6). The remaining chapters are dedicated to reviewing the various IoT applications that will benefit from Fog networking.