Routing protocols for Wireless Adhoc Networks

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Routing protocols for Wireless Ad-hoc Networks

• Raghava Kashyapa
• DAWN Research Laboratory
• Dept of EECS
• Washington State University

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Introduction

• Present an overview of existing routing
  protocols.
• In specific present two interesting Energy
  efficient schemes
• Discuss their applicability in Sensor networks

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Ad-hoc Routing Protocols

• Table Driven Routing Protocols
• Attempt to maintain routing information about
  every node in the network.
• Source Initiated On-Demand routing
• Creates routes only when desired by the source
  node.
• Once created it is maintained till the route is
  no longer required

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Table Driven Routing

• Destination Sequenced Distance Vector Routing
• Based on the classical Bellman-Ford Algorithm
• Maintains a routing table of all the nodes in the
  network and the no. of hops to the node
• Periodically updates the table

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Table Driven Routing contd..

• Cluster head Gateway Switch Routing
• Nodes are grouped into clusters
• Routing is from node to cluster-head to gateway
  to destination cluster head

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1
6
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Source Initiated On-Demand Routing

• Dynamic Source Routing
• Route Discovery
• It firsts consults its Route cache to check for a
  route. If no route exists, then discover a
  route
• Route Maintenance
• With the aid of Route Error Packets
• TORA
• AODV
• ABR

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Energy efficient routing

• Previously presented routing protocols
• Energy efficiency has been addressed before
  but..
• Instead of minimizing the consumed energy,
  maximize the lifetime of the system.
• Similar problem Time to network partition is
  reported to be NP complete

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An Energy Conserving Routing Algorithm

• Sensor nodes
• Gateway nodes
• Transmitted power levels can be adjusted

Gateway node
Monitoring Nodes
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Maximizing the system lifetime
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Energy efficient Broadcast and multicast trees

• Focus on Source initiated broadcasting of session
  oriented traffic
• Makes use of the wireless multicast advantage
• Assumes discrete power levels

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The Wireless Multicast advantage
d2

• P 1/ ræ
• Transmit to D2
• Transmit to D1 and D1 to D2

R2
r12
s
d1
R 1
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Wireless multicast adv contd..
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Sensor Networks

• Data-Centric
• Application Specific
• Immobile or mobility is restricted
• Localized algorithms