Description
5G MAC Layer Mastery V2 is an in-depth, practical, and specification-aligned e-book designed to help telecom professionals, engineers, and advanced learners master the 5G NR MAC layer as defined in 3GPP TS 38.321 (Release 18). This book goes far beyond theory, combining clear explanations, real-world examples, calculations, and protocol workflows to build strong MAC-layer expertise.
The e-book systematically explains how the MAC layer works in real networks, covering everything from logical-to-transport channel mapping to HARQ, Random Access, Scheduling Requests, BSR, DRX, BWP operation, Beam Failure Recovery (BFR), and Radio Link Failure (RLF), all mapped directly to 3GPP clauses.
What This E-Book Covers
✔ MAC Layer Functions (TS 38.321 §4.4)
Clear explanation of MAC responsibilities with practical examples such as logical-to-transport channel mapping, multiplexing/demultiplexing, scheduling information reporting, HARQ, logical channel prioritization, and radio resource selection
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✔ Random Access Procedure (TS 38.321 §5.1)
Detailed coverage of CBRA and CFRA flows, beam-based RACH, Early Data Transmission (EDT), PRACH power control, RA-RNTI calculation, RAR MAC structure, MSG3 resource allocation, and timing advance with step-by-step numerical examples
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✔ HARQ Operation (TS 38.321 §5.3.2)
Comprehensive explanation of DL asynchronous HARQ and UL synchronous HARQ, HARQ entities and processes, adaptive vs non-adaptive retransmissions, HARQ feedback handling (C-DAI, T-DAI), and buffer management with flow diagrams
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✔ Buffer Status Reporting – BSR (TS 38.321 §5.4.5)
Covers Regular, Periodic, and Padding BSR, BSR MAC-CE formats, LCID mapping, BSR type selection logic, and real padding-based BSR calculation examples that reflect actual UE behavior
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✔ Scheduling Request – SR (TS 38.321 §5.4.4)
Explains SR purpose, configuration, triggering conditions, timers (sr-ProhibitTimer, sr-TransMax), SR retransmissions, fallback to Random Access, and coordination with BSR using practical traffic scenarios (eMBB vs URLLC)
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✔ Advanced Topics
DRX operation
BWP operation and switching
Beam Failure Recovery (BFR)
Radio Link Failure (RLF) triggers and recovery
All explained with protocol-level clarity and spec references5G MAC Layer Mastery V2
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Who Should Read This Book
5G L2 / MAC / PHY Engineers
5G Protocol Test & Validation Engineers
R&D and System Engineers
Telecom Trainers & Advanced Students
Professionals preparing for 5G interviews and certifications
Why This Book Stands Out
✅ Fully aligned with 3GPP TS 38.321 (Rel-18)
✅ Explains why + how, not just what
✅ Includes real calculations, examples, and flows
✅ Ideal for log analysis, debugging, and interviews
✅ Written in a clear, trainer-friendly and industry-ready style
Internal Links
External Links
3GPP TS 38.321 – MAC Specification
👉 https://www.3gpp.org/ftp/Specs/archive/38_series/38.321/
Aman Kumar –
This e-book explains the 5G MAC layer in a very clear and practical manner. The Random Access, HARQ, and BSR examples helped me finally connect TS 38.321 theory with real network behavior.
Pooja Mehta –
Excellent content for protocol engineers. The step-by-step explanation of HARQ processes, SR vs BSR logic, and scheduling flow is extremely useful for log analysis and interviews.
Rahul Singh –
Unlike generic 5G books, this one focuses on how the MAC layer actually works in practice. The numerical examples and flow diagrams make complex topics very easy to understand.
Sneha Iyer –
A must-have e-book for anyone preparing for 5G L2 roles. The coverage of Random Access, DRX, BWP operation, and MAC scheduling is perfectly aligned with 3GPP Rel-18.
Karthik R –
Very well-structured and industry-oriented. The explanations of BSR types, SR timers, and HARQ feedback handling clarified many doubts I had while working on live projects.
Neha Gupta –
This e-book bridges the gap between specifications and implementation. Ideal for engineers involved in testing, validation, and protocol troubleshooting.
Ankit Sharma –
“This e-book explains the 5G MAC layer in a very structured and practical manner. The examples on HARQ, BSR, SR, and timing advance are extremely helpful for understanding real network behavior. A must-read for anyone preparing for L2/L3 interviews.”
Priya Nair –
“I have referred to multiple 5G resources, but this book stands out for its clarity and mapping with 3GPP TS 38.321. The step-by-step explanations and numerical examples make complex MAC concepts very easy to grasp.”
Rohit Verma –
“Excellent coverage of Rel-18 MAC enhancements. The sections on Random Access, BFR, and HARQ flows with logs are very close to real industry scenarios. This book helped me gain confidence in MAC-layer discussions during interviews.”
Sneha Kulkarni –
“The best part of this e-book is the practical explanation of scheduling, BSR types, and SR procedures with real examples. It bridges the gap between specs and implementation beautifully. Highly recommended for working telecom engineers.”
Mohammed Faisal –
A very well-designed learning resource for advanced 5G MAC concepts. The flow diagrams, tables, and spec references make it ideal for self-study as well as corporate training. Truly a mastery-level book.”
Abhishek Tiwari –
This book provides a crystal-clear understanding of 5G MAC layer fundamentals and advanced procedures. The explanation of Random Access, HARQ, and Scheduling Request is very well structured and easy to follow.
Snehal Patil –
The numerical examples for Timing Advance, UL grant calculation, and BSR types are excellent. This e-book helped me connect 3GPP specifications with real network logs.
Vikas Malhotra –
One of the most practical MAC-layer books I have read. Concepts like Logical Channel Prioritization, multiplexing/demultiplexing, and resource selection are explained in a very intuitive way.
Farah Siddiqui –
The coverage of HARQ operation—both synchronous and asynchronous—is outstanding. Retransmission scenarios with adaptive and non-adaptive flows are explained exactly as seen in real deployments.
Sandeep Rao –
This e-book is perfectly aligned with 3GPP Rel-18 and highly useful for protocol testing and interview preparation. The clarity of explanations and flow diagrams makes complex MAC procedures easy to understand.