960  6LoWPAN Fundamentals and Architecture

960.1 Overview

6LoWPAN (IPv6 over Low-Power Wireless Personal Area Networks) is an adaptation layer that enables IPv6 communication over IEEE 802.15.4 radio networks. It solves a fundamental mismatch: IPv6 headers are 40 bytes fixed, but 802.15.4 frames only have ~102 bytes available after MAC headers.

ImportantThe Core Problem
  • IPv6 header: 40 bytes minimum
  • UDP header: 8 bytes
  • 802.15.4 frame: 127 bytes max (~102 usable)
  • Available for payload: Only 54 bytes without compression!

6LoWPAN Solution: Intelligent header compression (IPHC) reduces 40-byte IPv6 headers to 2-7 bytes, plus fragmentation support for larger payloads.

960.2 Chapter Guide

This comprehensive 6LoWPAN topic has been organized into focused chapters for easier learning. Start with the overview and progress through each chapter in order:

960.2.1 Foundation Chapters

Chapter Description Difficulty
6LoWPAN Overview Introduction, problem definition, technology summary, beginner-friendly explanations Beginner
Header Compression (IPHC) IPHC encoding, address compression modes, NHC for UDP, worked examples Intermediate
Fragmentation and Reassembly FRAG1/FRAGN headers, reliability calculations, reassembly code Intermediate

960.2.2 Advanced Chapters

Chapter Description Difficulty
Routing with RPL DODAG topology, mesh-under vs route-over, ETX metrics, 6LoWPAN-ND Advanced
Deployment and Decisions Smart building example, border router design, protocol selection guide Advanced
Common Pitfalls 7 common mistakes, troubleshooting scenarios, best practices Advanced

960.2.3 Hands-On Lab

Chapter Description Difficulty
Lab Simulation Complete ESP32 Wokwi simulation with IPHC, fragmentation, and RPL Advanced

960.3 Learning Path

Recommended order:

  1. Overview - Understand the problem and solution (30 min)
  2. Header Compression - Learn IPHC encoding (45 min)
  3. Fragmentation - Understand packet splitting (30 min)
  4. Routing - Learn RPL and mesh forwarding (45 min)
  5. Deployment - Apply to real scenarios (30 min)
  6. Pitfalls - Avoid common mistakes (20 min)
  7. Lab - Hands-on practice (60 min)

Total estimated time: ~4.5 hours

960.4 Quick Reference

Feature 6LoWPAN Value
Standard IETF RFC 4944, RFC 6282
Physical Layer IEEE 802.15.4
Compression IPHC (40 bytes → 2-7 bytes)
Fragmentation Up to 1280 bytes over 102-byte frames
Routing RPL (RFC 6550)
Addressing Full IPv6 support
Use Cases IP-based IoT, smart buildings, industrial