1. Extending IP to Low-Power, Wireless Personal Area Networks
Communication I
Extending IP to Low-Power, Wireless Personal Area Networks
Ramjot Singh Varun Sachdeva

2. Internet Protocol Stack
Layer 2 is link layer. Layer 3 is etwork layer.

3. IPv4 vs IPv6
Addresses are 32 bits (4 bytes) in length. Addresses are 128 bits (16 bytes) in length.

4. IPv6 Protocol Stack

5. Motivation Microcontrollers use 802.15.4
IPV6 over seen impractical
IPV6 by design very resource intensive
Resulted in proprietary communication protocols (Zigbee etc)
6LoWPAN: Efficient IPV6 communication over

6. 6LowPAN Architecture
6LoWPAN is a simple low cost communication network that allows wireless connectivity in applications with
limited power and relaxed throughput requirements as it provides IPv6 networking over IEEE networks
[3]. It is formed by devices that are compatible with the IEEE standard and characterized by short range,
low bit rate, low power, low memory usage and low cost, where its architecture is shown in Figure 1 [12]. When a
lower processing capability sensor node in a 6LoWPAN or so-called reduced function device (RFD) wants to send
its data packet to an IP-enabled device outside the 6LoWPAN, it first sends the packet to the higher processing
capability sensor node or so-called full function device (FFD) in the same PAN. The FFDs which react as a router in
6LoWPAN will forward the data packet hop by hop to the 6LoWPAN gateway. The 6LoWPAN gateway that
connect to the 6LoWPAN with the IPv6 domain will then forward the packet to the destination IP-enabled device by
using the IP address.

7. IPV6 over 802.15.4 IPV6: 128 bit addresses(vs 32 bit IPV4)
IPV6 designed for current WLAN technologies: Wi-Fi and Ethernet
Ample power and capability
LoWPAN: Lower power, range and resources
Low frame length, rate and address space
Need for efficient seamless communication
ZIGBEE Network Speed kbps
Network Range - 70 meters
Typical Applications - home automation, remote controls
Handle devices
Low power - designed to last long on battery
Network join time - 30 ms

8. 6LoWPAN Adaptation Layer
Primary elements:
Header compression: Makes use of common values occurring in packets(TCP, UDP & ICMP)
Fragmentation: Used to support IPV6 minimum MTU requirement
Layer-two forwarding:
The adaptation layer may carry link-level addresses for the ends of IP hop
The IP stack might do intra-PAN routing via layer-three forward (each radio hop is a IP hop)

9. Encapsulation Header Format

10. Network and Transport Layer Header Compression
HC1 compression scheme:
64-bit source-destination network prefix converted to a single bit when known
Next Header field reduced to 2-bits for TCP, UDP or ICMP packet
Traffic class & Flow Label reduced to a single bit when both 0
Fully compressed, the Ipv6 header reduced to 2 bytes

11. Network and Transport Layer Header Compression

12. Adaptation Layer Evaluation
Analyze by computing energy cost of communication (variable-sized payload)
Compare 6LoWPAN compressed headers v/s Uncompressed IPV6 headers
Compare inter-network v/s intra-network v/s link-local network in compressed headers.
Significant cost reduction

13. Adaptation Layer Evaluation

14. 6LowPAN Architecture Mesh Under Organization Route Over Organization
No routing at network layer
Adaptation layer does routing and forwarding
Route Over Organization
Routing done at IP layer (each node acts as an IP router)
Supports network layer forwarding
Either design can be chosen

15. Addressing in IPV6/6LoWPAN
Each host generates a link-local unicast address
Mesh Under: This address sufficient for communication over LoWPAN, routable address required to communicate outside
Route Over: This address sufficient for communication over single hop, routable address required for multiple hops or outside communication

16. Autoconfiguration and Neighbor Discovery
Autoconfiguration configures interface addressing
IP addresses derived from short-link addresses
Address configuration depends on design
ND lets node discover its neighbors by link-local multicasts
Multicast floods network in Mesh Under design, better fits for Route Over design

17. Routing LowPAN routing protocols operate on incomplete information
Inter-network routing done using IP routing protocols
Intra-network routing works on link addresses to reduce table width
Makes use of link-address v/s IP address mapping
Traditional routing protocols require full network topology information
Frequent floods
Cache maintenance takes memory
LowPAN routing protocols have to operate in incomplete information and tolerate inconsistency

18. Conclusion
6LoWPAN opens the opportunity of using IPV6 over links
Brings standard IPV6 protocol to low-power wireless networks
Communicate via IPV6 with efficiency
Implementation of high quality IPV6 network forwarding, routing and transportation of TCP and UDP traffic
Opens the domain of extending this architecture and implement concepts like proxies, DNS and application layer protocols

19. References
[1]Jonathan W. Hui and David E. Culler- 6LoWPAN: Extending IP to Low-Power, Wireless Personal Area Networks, IEEE Internet Computing, Jul/Aug, 2008
[2]Li-Wen Chen- RFC Transmission of IPv6 Packets over IEEE Networks
[3]Jonathan Hui, David Culler and Samita Chakrabarti- 6LoWPAN: Incorporating IEEE into the IP architecture, Internet Protocol for Smart Objects (IPSO) Alliance
[4]Gee Keng Ee, Chee Kyun Ng, Nor Kamariah Noordin and Borhanuddin Mohd. Ali- A Review of 6LoWPAN Routing Protocols
[5] Jonathan Hui- Compression Format for IPv6 Datagrams in 6LoWPAN Networks

20. Thank You