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A Measurement Study of Vehicular Internet Access using In Situ Wi-Fi Network

A Measurement Study of Vehicular Internet Access using In Situ Wi-Fi Network. Vladimir Bychkovsky, Bret Hull, Allen Miu, Hari Balakrishnan and Samuel Madden Presented By: Galileo Namata. Basic Problem.

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A Measurement Study of Vehicular Internet Access using In Situ Wi-Fi Network

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  1. A Measurement Study of Vehicular Internet Access using In Situ Wi-Fi Network Vladimir Bychkovsky, Bret Hull, Allen Miu, Hari Balakrishnan and Samuel Madden Presented By: Galileo Namata

  2. Basic Problem • Can a “grassroots” wireless Internet service, provided by users who “open-up” their 802.11 (Wi-Fi) AP, be created for mobile clients? • Can such an unplanned network service provide reasonable performance to clients at vehicular speeds? • What is the expected performance for users in automobiles as they move?

  3. Motivation • Cartel • Cartel is a mobile sensor computing system designed to collect, process, deliver and visualize data from in car sensors • Reference: • Bret Hull, Vladimir Bychkovskiy, Kevin Chen, Michel Goraczko, Eugene Shih, Yang Zhang, Hari Balakrishnan, Samuel Madden. CarTel: A Distributed Mobile Sensor Computing System. In Proceedings of SenSys, 2006. http://db.csail.mit.edu/pubs/fp02-hull.pdf

  4. CarTel In A Nutshell • Computer • 266 MHz with 128 MB of RAM and 1 GB of flash memory • Varied Sensors • GPS Receiver, OBD-II Interface, Wi-Fi Interface, Digital Camera

  5. CarTel In A Nutshell

  6. CarTel In A Nutshell • Commute Time Analysis • Researcher shortened his commute • Traffic Hot Spot Heuristic • Identify Traffic Areas automatically • Image Acquisition • Google Maps with Pictures • Wi-Fi Measurement • Automotive Diagnostics

  7. CarTel Example

  8. Communication • CarTel data is set up to be automated • Don’t need to be plugged in to get data • Want to be able to get current data • Use In Situ Wi-Fi Networks • In Situ – Latin “in the place” • All data, sent through open networks • Updates and queries to CarTel nodes • Data from sensors to main server

  9. What’s the Performance? • Experiment: • Use CarTel system in and around Boston Metropolitan Area and Seattle • 9 cars total, 290 “drive hours” • Measure Time For: • Scan • Association • Address Configuration • Single End to End Ping • Connectivity and uploads

  10. Network Activity Timeline

  11. Geographic Coverage

  12. IP Address Acquisition Latency

  13. Effects of Speed

  14. AP Connectivity

  15. Throughput

  16. Related Work • Ott and Kutscher – Controlled experiment measuring network connection from fixed test bed • Gass et al – Similar measurement but in California desert • “War Driving Maps”

  17. Wardriving

  18. Discussion • Open Wi-Fi Networks • Don’t wanna get sued • “Safe Harbor” Laws • Don’t wanna get in trouble with ISP • Fon System (http://en.fon.com) • Public Free Internet? • Google in SF • Don’t Wanna Get Hacked? • Specialized, easy to manage hardware

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