Notes
Slide Show
Outline
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Traffic Balancing in Wireless MESH Networks
  • Xiaojing Tao, Thomas Kunz, David Falconer
  • Systems and Computer Engineering
  • Carleton University
  • tkunz@sce.carleton.ca
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Wireless MESH
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Traffic in Wireless MESH:
Potentially Unbalanced
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New Routing Algorithm: TB
  • Explained in previous presentation for MANETs
  • Nodes measure medium busy time, decide whether node is in congested area based on dynamically determined threshold
  • Sender picks route to destination (here: one of the gateways) that has lowest number of overloaded nodes
  • To route towards a node in a MESH: have to trigger router discovery from ALL gateways (or have destination trigger “reverse” route discovery to all gateways)
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Simulation Results I:
2 Gateways, high mobility
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Simulation Results II:
2 Gateways, low mobility
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Interesting Issue: Gateway/AP Location
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Performance vs. Gateway Location
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Conclusions and Future Work
  • Mesh networks: Gateways/APs are performance bottlenecks
  • MANET routing protocols, routing to closest AP, tend to (temporarily) overload some APs
  • TB can improve network performance by distributing traffic more equally to all APs
  • Future Work:
    • Location of APs has major impact on performance
    • IEEE 802.11 is poor protocol for APs, as they need to access media more frequently than nodes
    • MESH are more static, should we re-issue route discovery periodically?
    • Explore TB in our wireless mesh testbed, based on IEEE 802.11 a/g radios and Intel IXP 425-based wireless routers