How 4 years of working in telecom turned into a published book
Hi everyone,
I'm a telecom engineer with nearly 4 years of experience, but I actually come from a Computer Science background. I completed my Master's in Computer Applications (MCA) expecting to work in general networking or software engineering.
One day, I received an opportunity to work in telecom core networks. At first, I had no idea what IMS, VoLTE, HSS, MME, Diameter, MAP, CAMEL, or even roaming really meant. None of these topics were covered in depth during my university studies.
As I started working, I realized that understanding 2G, 3G, LTE, VoLTE, IMS, Roaming, and 5G Core Networks wasn't optional, it was essential. My job involved testing live operator networks, troubleshooting signaling issues, analyzing call flows, and working with network operators across different countries.
To help myself learn, I began taking detailed notes every day.
These weren't textbook notes. They were based on real-world experience, industry standards, customer deployments, troubleshooting sessions, and the technologies we use in production today.
Over the years, those notes grew into a complete learning guide.
It covers:
- Telecom network evolution from 2G to 5G
- Core network architecture
- IMS and VoLTE fundamentals
- International roaming
- SIP, Diameter, MAP, CAP, GTP, RTP, SCTP, and other telecom protocols
- Detailed signaling procedures and call flow diagrams
- Real-world explanations of services like:
- Location Update
- Mobile Originated & Mobile Terminated Calls
- SMS
- Mobile Data/Browsing
- LTE Attach
- IMS Registration
- CSFB
- 5G Registration
- Roaming procedures
I initially shared these notes with a few colleagues and telecom professionals, and the feedback was overwhelmingly positive. Many told me they found them much easier to understand than traditional documentation.
That encouraged me to turn the notes into a book.
"Understanding Mobile Network Architecture & Service Flows,"
My goal wasn't to write an academic textbook, but to create a practical guide for:
- Students entering the telecom industry
- Telecom professionals who want to strengthen their fundamentals
- Engineers preparing for interviews
- Anyone curious about how mobile networks actually work behind the scenes
I'd genuinely love to hear your feedback and suggestions from fellow telecom professionals.
Thank you!