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1. 6LoWPAN
(IPv6 over Low power Wireless
Personal Area Networks)

2. Introduction
• IP based devices
• web services
• security
• management
• frame size
• issues
• power & duty cycle
• multi cast
• topology
• bandwidth
• reliability
Internet of things

3. Related Technologies
 RFC 4944
 ISA 100
 IPSO

4. Applications
 Home building automation
 Health care
 Industry Automation & Logistics
 Vehicular Automation
 Environmental monitoring
and many more

5. Architecture

6. Protocol stack
• UDP is preferred

7. Link layers
 Compatibility with existing technologies like
802.15.4, Sub-GHz Radio and Power- line
communications.
 Adaptation for IP
 Addressing of nodes (Locally & Globally)

8. Addressing
 Extended Unique identifier(EUI-64) -- like Zigbee
 Configurable short addressing(8-16 bits)
 Similar like IPv6 64 bits IID is used--- generally
called Stateless Address Auto configuration (SAA)

9. Forwarding and Routing
1. IP Routing Model
2. LoWPAN Routing(L3 , Route over)

10. Forwarding and Routing (contd..)
3(a). DLL mesh forwarding (L2, Mesh Under)
3(b). LoWPAN adaptation (L2, Mesh Under)

11. Header Compression
 Headers of IP is compressed(IPv6 headers occupy more space)
 Router decompresses the header and transmits over different link
 MTU is not sufficient
 Need to achieve flow control
 Must be used when needed
 The throughput of network reduces
Fragmentation and Reassembly

12. Data Packet of 802.15.4
802.15.4 IPv6 header Payload
802.15.4 Mesh Addr Frag IPv6 header Payload
802.15.4 Fragmentation IPv6 header Payload
128 bytes
Payload
decreases
Fragmentation Header
Mesh Header

13. IP Header format (HC)
 For IP , HC1 is used
 HC2 bit indicates further transport protocols
 UDP, TCP, ICMPv6
IPv6 Header
UDP

14. RFC4944’s HC
 TF,FL into 2 bits
 Version, Payload Length, Link
Local Prefix
 UDP ports (61616-61631)
Uni Cast
Multi Cast
Global

15. Improved HC (IPHC)
 TF,FL are individually
compressed
 Hop limit
compression
 Removes prefixes for
IPv6 addresses
 Supports Multicast
for ND, SLAAC
 4 bit index represents
16 contexts (if CID is
set)
U
M
G

16. Networking Issues
 Establishing a network (Commissioning)
◦ new node joining
◦ Network re-organizing
 Uses
◦ Service Set ID (WLAN)
◦ Security (Wireless Protected Access)
 Prefix match -- Home network
 Neighbor Discovery
◦ DHCPv6 (Stateless Address Auto configuration)
◦ Registration
◦ Reg. collision
◦ Multi-hop registration
◦ Various operations (node, router, edge router)
Bootstrapping

17. Networking Issues (contd..)
 Objectives
◦ Confidentiality
◦ Integrity
◦ Availability
 Layer2 mechanisms
◦ As 802.15.4 implements AES(CCM, RFC 3610)
◦ 13 byte key based on 8 byte MAC Id
◦ 2^22= 7 weeks of key repetition
 Layer3 mechanisms (Internet Key Exchange [RFC 2409])
◦ Doesn’t suit for LoWPANs
 Key Management (Enhanced L3)
◦ Username & Password
◦ Long, Short, Group, Pair wise keys
Security

18. Other Aspects
 Mobility
◦ Roaming (macro)
◦ Handover (micro)
 Causes
◦ Physical movement
◦ Radio channel
◦ Network performance
◦ Sleep schedules
◦ Node failure
 Node & Network controlled
(Wi-Fi, cellular systems)
 Solutions for Mobility
◦ Commissioning
◦ Bootstrapping
◦ Security
◦ Updating DNS
◦ Notifying upper layers
So far nodes are considered stationary

19. Other Aspects (contd..)
MIPv6 Proxy Home Agent

20. Other Aspects (contd..)
Proxy MIPv6 NEMO (NEtwork MObility)

21. Application protocols
 General IPv6
◦ HTTP, FTP, SIP, SNMP, RTP, SLP
 Need modifications
 SOAP, REST (Simple Object Access Protocol,
REpresenational State Transfer)
 Need Port Address

22. Application protocols (contd..)
 Networking
 Host Issues
 Compression
 Security

23. Application protocols (contd..)
 Protocol paradigms
◦ End to End
◦ Real Time Streaming / Session
◦ Pub/ Sub
 Common Protocols
◦ Web service protocols
◦ MQTT (MQTT-S)
◦ ZIGBEE Compact Application Protocol
◦ Service Discovery
 SLP, UPnP, DPWS
◦ Industry Specific (BACnet, oBIX, ANSI c12.19)
 ZCAP, MQTT has own discovery features

24. Implementing 6lowpan
Single Chip Two Chip

25. Implementing 6lowpan (contd..)
 Protocol Stacks
◦ ContikiOS & uIPv6
◦ TinyOS & BLIP
◦ Sensinode NanoStack
◦ Jennic 6LoWPAN
◦ Nivis ISA100 (Industrial Standard)

26. Implementing 6lowpan (contd..)
 ContikiOS
◦ C
◦ MSP430, AVR, HC12, Z60,
etc..
◦ 2kB RAM, 40kB ROM
◦ LoWPAN Support
◦ Multitasking
◦ Event driven kernel
◦ uIP stack
◦ Thread based
◦ COOJA Simulator
◦ TMote
 TinyOS
◦ nesC
◦ MSP430, AVR
◦ 0.4kB RAM
◦ LoWPAN Support
◦ BLIP
◦ TOS Simulator
◦ FIFO
◦ OS merges with Program
◦ TelosB, IMote etc..

27. Implementing 6lowpan (contd..)
Application development
Hardware Interaction layer
Hardware Implementation Layer
nesC
TinyOS
H/W Platform
Contiki OS
TinyOS