The mobile cellular network has its origins in Telco voice networks, but 5G adopts the principles of modern clouds. This book describes how 5G leverages horizontally scalable microservices, Software-Defined Networking (SDN), and cloud operational practices such as DevOps. It provides a detailed introduction to mobile networking that is understandable to a general computing systems audience. Features:Emphasizes underlying concepts, key principles and design choices, going beyond the acronym soup of standards. Describes the main open source components used to build a private 5G network and the rationale for their selection. Walks through the architecture of 5G from the radio to the mobile core. Includes sample code used in configuration and operations of a real private 5G network deployed across a dozen enterprises. "Private 5G networks are something you can touch, code, and deploy yourself. Armed with the knowledge of how 5G access networks work, and with hands-on experience with open source software, just imagine the places you'll go!" - Jennifer Rexford, Princeton University