This book systematically covers the entire mobile security spectrum. Drawing on real-world implementations and architectures, this guide bridges the gap between theoretical security concepts and practical deployment. Each chapter combines technical depth with actionable insights, featuring designs that demonstrate how service providers have successfully implemented defense-in-depth approaches across 3G, 4G, IMS, virtualized environments, RAN, transport, multi-access edge computing (MEC) infrastructures, and other telecom components.