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6LoWPANExtending IP to Low-Power WPAN

By: Shadi Janansefat

CS441 Dr. Kemal Akkaya

Fall 2011

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• A review on WSN

• Introducing 6LoWPAN

• 6LoWPAN Adaptation Layer

• 6LoWPAN Stacked Headers

• Routing in 6LoWPAN

• Conclusion

Contents:

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What is a WSN?

• WSN: Wireless Sensor Network

• A network with wireless links formed in an ad-hoc

manner

• The nodes are collaborative spatially distributed

sensors

• Usually consists of a large number of nodes

• All nodes are used for a common task

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Applications of WSNs

• Networking unattended sensor nodes have significant

impact on the efficiency of many applications:

▫ Military applications such as combat field surveillance

▫ Civil applications such as security and disaster

management

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Characteristics of a Sensor Node

• Small device that can sense information around itself

• Capable of short range communication

• Constrained in energy supply and bandwidth

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IEEE 802.15.4

• A MAC layer protocol for WSNs

• Uses CSMA-CA channel access

• Low power consumption

• Supports star and peer-to-peer topology

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6LoWPAN: Extending IPv6 to Low Power WPANs

• 6LoWPAN defines how to extend IPv6 over low data rate, low power networks(LoWPAN)

• Why? ▫ Employing tools already developed rather than starting

from scratch

• Challenges ▫ Large size of IPv6 datagram ▫ A responsive network layer is needed ▫ The need for supporting Multi-hop topology

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IPv6 over IEEE 802.15.4

• 6LoWPAN introduces an adaptation layer between the

IP stack’s link and network layers

• The adaptation layer enables efficient transmission of

IPv6 datagrams over 802.15.4

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6LoWPAN Adaptation Layer

• Introducing the idea of stacked header:

▫ You only pay for what you use

• This layer provides :

▫ Header compression

▫ Fragmentation

▫ Support for layer-two forwarding

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6LoWPAN Stacked Headers

• All header formats are identified using dispatch header

• The mesh header is used to encode the hop limit

• The fragmentation header supports the fragmentation and

reassembly of payloads

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Utilizing Separate Headers

• 1)Point to Point Small Packet

• 2)Fragmented Large Packet

• 3)Mesh Transmitted Packet

Routing in 6LoWPAN

• Mesh Under Routing

▫ No IP routing

▫ Routing within the LoWPAN

• Route Over Routing

▫ Routing at the IP layer

▫ Utilizing network-layer capabilities defined by IP

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Conclusion

• 6LoWPAN introduces a high quality IPv6 network stack on 802.15.4

• 6LoWPAN does not solve all of the problems and issues related to sensor networks

• Future research areas:▫ Neighbor Discovery▫ secure neighbor discovery▫ service discovery

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Thank YouFor Your Attention

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