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The Meraka Indoor wireless mesh test bed A new multi hop routing benchmarking tool

The Meraka Indoor wireless mesh test bed A new multi hop routing benchmarking tool. David Johnson Senior Researcher Wireless Africa Programme Meraka CSIR. 450 million rural people in Africa are isolated from the rest of the world. Connect them all by 2017. Sound crazy?.

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The Meraka Indoor wireless mesh test bed A new multi hop routing benchmarking tool

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  1. The Meraka Indoor wireless mesh test bedA new multi hop routing benchmarking tool David Johnson Senior Researcher Wireless Africa Programme Meraka CSIR

  2. 450 million rural people in Africa are isolated from the rest of the world

  3. Connect them all by 2017

  4. Sound crazy?

  5. How do these sound?

  6. 7 trillion wireless devices serving 7 billion people by 2017 …Wireless World Research Forum

  7. Affordable mobile communications for half the world's population by 2015 …Nokia

  8. Half the world have Internet access by 2015 …AMD 50x15

  9. Creates cognitive dissonance

  10. Here’s how it could be done

  11. Turn the “first mile” into an open bazaar of community networks

  12. As easy to setup as a TV

  13. Telcos just provide backhaul

  14. Income stays in the communities

  15. Modernized without being urbanized

  16. Ubuntu = community networks = mesh networks

  17. Plenty of research problems to address • Routing protocols and routing metrics • Gateway selection for multiple gateways • Power efficiency • Auto channel allocation • Distributed services • Multimedia over mesh • Clustering optimization • Smart antennas for mesh • Business models for village entrepreneurs • Security over mesh • Vulnerability of first time exposure to the internet • Building technical skills in developing regions • Logistics

  18. Why build a test bed?

  19. Mathematical models good enough for rules of thumb but no tractable solution for a real network

  20. Simulation models good for early protocol development and testing but still far from reality

  21. Real outdoor wireless = reality but difficult to build and manage

  22. Indoor test beds provide controlled environment and expose theoretical simplifications

  23. Construction of the meraka wireless grid

  24. Construction of the meraka wireless grid

  25. Construction of the meraka wireless grid

  26. Construction of the meraka wireless grid

  27. Construction of the meraka wireless grid

  28. Challenges when building experiments

  29. Challenges when building experiments

  30. Challenges when building experiments • Which combination of mode/rate/txpower to use • Experiments are time consuming ... 52 hours to test 4 routing protocols using all combinations of 49 nodes in the grid with 20 second test time

  31. Electromagnetic modelling of the grid Done with WIPL-D modelling software

  32. Electromagnetic modelling of the grid

  33. Results – 49 node multi hop chain

  34. Results – 49 node multi hop chain

  35. Results – 49 node multi hop chain • After 4 hops • Gupta best = 50% • Gupta worst = 42.47% • Gupta indoor measurements = 9.74% • Meraka lab = 25.7%

  36. Choosing routing protocols to benchmark

  37. Results – hop count distribution

  38. Results –Routing traffic overhead

  39. Results –Routing traffic overhead

  40. Results – throughput, packet loss, delayString of 7 nodes

  41. Results – throughput, packet loss, delayFull 7x7 grid

  42. Comparison of throughput to baseline

  43. Conclusions • Proved that multi hop wireless networks possible on scaled test beds (up to 5 hops were achieved in a space of 7Mx7M) • Complexity in the grid is high and produces a worst case scenario for routing algorithms. • The AODV protocol showed the weakest performance but had the lowest routing overhead. • DYMO showed good results for its low routing overhead with the least amount of delay for the full 7x7 • The RFC version of OLSR had the best overall performance the full 7x7 grid. • OLSR with the ETX extension performed better in medium size networks of about 21 nodes.

  44. Future improvements to the mesh lab • Compare results to NS2 simulations • Add a lab sandbox • Add a lab scheduler to make it simple for multiple interested parties to run experiments • Build a measurement framework to simplify setting up experiments • Test virtual mobility and install a roaming robot • Experiment with parameters beyond the RFC values for routing protocols • Add support for power measurements • Add support for control of smart antennas

  45. For further information http://wirelessafrica.meraka.org.za

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