📖

The 5G Core

Architecture and Functions Explained

A Practical Guide to 5G Core Networks, Service-Based Architecture, and Integration with BSS/OSS

Front Cover

Front Cover

Back Cover

Back Cover

📚 Now Available on Amazon

What started as articles on this website has grown into a comprehensive guide that will help professionals across the telecom industry navigate the complex world of 5G Core networks.

ISBN: 979-8251831801 (Paperback)

✍️ Why I Wrote This Book

I have seen too many professionals struggle with 5G Core. Some come from 4G backgrounds and try to map familiar concepts directly. They look for the MME and are confused when they find AMF instead. They expect Diameter and encounter HTTP/2.

This book bridges that gap. It starts from absolute fundamentals and builds up to advanced concepts, always keeping the practical, real-world perspective that I have developed over years of implementing these systems.

🌟 What Makes This Book Different

If you have been reading this website, you already know my style. I believe complex topics can be made accessible when explained clearly, with attention to both the "what" and the "why."

📡 Core Architecture

  • Service Based Architecture (SBA) explained simply
  • Deep dives into AMF, SMF, UPF, PCF, NRF, UDM, AUSF, NSSF, NEF, CHF
  • Complete call flows for registration and PDU session
  • Network Slicing for customized services

⚙️ Network Operations

  • 5G Identifiers, Subscription management, Protocols
  • Integration with OSS (Management, orchestration, automation)
  • 5G Roaming: Home Routed vs Local Breakout, SEPP, N32

💰 Interworking & Billing

  • Integration with BSS: CCS, Nchf, NEF for monetization
  • Interworking with 4G via N26 and EPS Fallback
  • Roaming charging: TAP and BCE settlement

👥 Who This Book Is For

🏗️ Solutions Architects – Mental model of 5GC + BSS/OSS integration
📊 Product Managers – What 5G capabilities can be monetized
🔧 BSS/OSS Professionals – Guidance on integrating with 5GC
📡 Network Engineers – Configure and troubleshoot 5GC
🎓 Students – Solid foundation bridging theory and practice
🔄 4G to 5G Movers – Clear understanding of what changed

🚀 The Journey to This Book

For those who have followed my website over the years, you know that I have been sharing knowledge on subscription and usage monetization, BSS/OSS architecture, and 5G core networks for a long time.

In 2025, I had the privilege of speaking at the India Mobile Congress in New Delhi, where I showcased a joint solution on AI-Powered Dynamic Product Catalogue for Telecom BSS. That experience reinforced my belief that the telecom community grows stronger when we share knowledge openly.

This book is my way of giving back. It distills not just technical knowledge, but also the lessons learned from delivering multiple projects.

🎓 Need Deeper Training?

If your team needs deeper training on any of the topics covered in this book, I offer one-on-one and group training sessions on end-to-end Telecom BSS/OSS, 5G charging, SaaS billing, and more.

"To everyone who has supported this website over the years, who has attended my sessions, who has reached out with questions and feedback. This book exists because of you."

Rajarshi Pathak

admin@rajarshipathak.com | www.rajarshipathak.com

📬 Let's continue learning together.

© 2026 Rajarshi Pathak | All Rights Reserved.

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