CEN4500C: Wireless Experiments Background

1. CEN4500C: Wireless Experiments Background Wireless Measurements: Shao-Cheng Wang ( shaochew@ufl.edu ) Encounter-based Networks: Sapon Tanachaiwiwat ( stanachai@gmail.com ) Instructor: Dr. Helmy 9/13/2007

2. Part I: Wireless MeasurementsAgenda • Introduction • Wireless measurement fundamentals • Tools • Potential Topics • Reference

3. http://www.ittc.ku.edu/wlan/images.shtml How does a coverage map look like?

4. coverage maps (cont’d)

5. Wireless fundamentals: SNR v.s. Distance

6. Wireless fundamentals: SNR v.s. Performance SNR v.s. Delivery ratio (emulator) SNR v.s. Delivery ratio (real measurement) SNR v.s. TCP Tput (real measurement)

7. Tools • Site-surveyer: Netstumbler (www.netstumbler.com) • Signal (in –dbm), SNR • AP MAC, SSID

9. Tools (cont’d) • HP iPAQ

10. Tools (cont’d) • Bandwidth test • NDT @ UF: http://ndt.server.ufl.edu:7123/ • TCP uplink/dnlink speed • Myspeed: http://myvoipspeed.visualware.com/ • UDP loss rate, jitter

11. Potential experiment topics • Coverage Map: • Create a coverage map of your choice: • SNR (enhanced with levels, dbm #’s) • SNR variations (weather, day/night) • Performance map • Find holes, additions, tech heterogeneity (11a/b/g/e/n) etc. (please coordinate between groups for the area of interest) • Reason about your choice and the implications of practicability • Observations/Surprises? • AP Hunting/Coverage/Handover • Locate APs in some specific areas/buildings • Create an AP-specific coverage map • AP-coverage/handover map for routes on campus • Observations and discussions about the AP planning (evaluation of planning, tradeoffs, applications, etc.)

12. Reference • Simon Byers and Dave Kormann, “802.11b access point mapping,” Communications of the ACM, May 2003. • Daniel Aguayo, John Bicket, Sanjit Biswas, Glenn Judd, Robert Morris, “Link-level Measurements from an 802.11b Mesh Network,” SIGCOMM 2004, August 2004 • Hiroto Aidal, Yosuke Tamura2, Yoshito Tobe2, Hideyuki Tokudal, “Wireless Packet Scheduling with Signal-to-Noise Ratio Monitoring,” LCN 2000

13. Part II: Encounter-based Networks Agenda • Introduction • Examples of Encounter based networking • Encounter-based worm interactions • Experiment for our class • Reference

14. B A E F D C Introduction • What is Encounter-based networking • Discontinuous path (Intermittent connection) • Store-and-forward (Bundles) • Similar to delay-and-disruption-tolerant-networking • Large delay • Low data rate • High loss rate • Networking relying on encounter or relationships between nodes (Social networking) • Basic assumptions of each node • Persistent storage • Willing to participate • Limitation of Power • Short Radio Range

15. Examples of encounter-based networks • Military tactical networks • Disaster relief • ZebraNet • Interplanetary networks • Underwater acoustic networks • Rural village networks • Other?

16. http://www.cs.rice.edu/~animesh/comp620/presentations/JFP04_D.pdfhttp://www.cs.rice.edu/~animesh/comp620/presentations/JFP04_D.pdf

17. Encounter-based worms • Future direction on worm attacks!! (Cabir, ComWar) • Rely on encounter pattern/relationships between users. • Close to flooding, i.e. Epidemic routing. • Propagate via Bluetooth connection (10-meter range) • Question: How can we alleviate this problem? • Traditional prevention at gateway such as firewall not effective against fully distributed attacks • Disconnected networks  No centralized update • Inspired by War of the Worms: CodeGreen worms launched to terminate CodeRed worms • Approach: Deploy automated generated predator worm to terminate prey worm  worm interaction

18. Encounter-based worm interaction Susceptible Predator Prey Prey and predator’s infection rate rely only on encounter characteristics

19. Experiment • Goal: To answer the following questions • Is the UF campus the good target for worm propagation, given that it propagate via Bluetooth? • If so, what places are most vulnerable? • If you want to stop the propagation with other worm, how can you do it effectively? • Equipments: iPAQs, your laptops, your strategies • Software: Modified Bluechat, Netstumbler, AirSnort, etc.

20. Bluetooth device discovery • Distribution of Bluetooth devices that you encounter during the day • E.g. Type of devices such as cell phone or lap top, brand of such devices such as Nokia, Motorola, etc. • Bluetooth game Design the strategies for • Largest of encounter rate per day • Largest number of unique devices • Largest number of stable devices • Different roles between teams e.g. Cops and Cons • Bluetooth and WLAN relationships • Can you derive the correlation between them? • Bluetooth worm interactions • To test the real worm propagation/ interaction with static/mobility • Parameters • Type of worm: one or two • Static or Mobile (human mobility) • Topology (for static): line, star, random • With/Without the super node, i.e., super mobile node which is our radio-controlled truck

21. Reference • E. Anderson, K. Eustice, S. Markstrum, M. Hansen, P. L. Reiher , “Mobile Contagion: Simulation of Infection and Defense” PADS 2005: 80-87 • S. Capkun, J. P. Hubaux, and L. Buttyan "Mobility Helps Security in Ad Hoc Networks" Fourth ACM Symposium on Mobile Networking and Computing (MobiHoc), June 2003 • F. Castaneda, E.C. Sezer, J. Xu, “WORM vs. WORM: preliminary study of an active counter-attack mechanism”, ACM workshop on Rapid malcode, 2004 • A. Chaintreau, P. Hui, J. Crowcroft, C. Diot, R. Gass and J. Scott, “Impact of Human Mobility on the Design of Opportunistic Forwarding Algorithms” IEEE INFOCOM, April 2006 • W. Hsu, A. Helmy, "On Nodal Encounter Patterns in Wireless LAN Traces", The 2nd IEEE Int.l Workshop on Wireless Network Measurement (WiNMee), April 2006 • S.Tanachaiwiwat, A. Helmy, "Encounter-based Worms: Analysis and Defense", IEEE Conference on Sensor and Ad Hoc Communications and Networks (SECON) 2006 Poster/Demo Session, VA, September 2006 • A. Vahdat and D. Becker. Epidemic routing for partially connected ad hoc networks. Technical Report CS-2000.