5G/LTE Call Process (Focus on Device): From Practical Analysis to Big Tech Technical Interviews

A practitioner with over 25 years of experience in device verification and commercialization in the telecommunications field provides a detailed explanation of the entire 5G/LTE call-processing flow, centered on device protocols. Starting with the basic structure of the UE–Network Interface, the content systematically connects the access, registration, data paths, and mobility procedures of LTE, NSA, and 5G SA from the fundamentals onward. Through diagrams and examples of RRC and NAS messages, complex procedures are organized systematically to help readers quickly understand the overall flow and grasp the key concepts.