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CIS 6930: Workshop Research Introduction and Lab Assignments

Wireless Measurements: Shao-Cheng Wang ( shaochew@ufl.edu )

Trace Analysis: Wei-jen Hsu ( wjhsu@ufl.edu )

Encounter-based Networks: Sapon Tanachaiwiwat ( stanachai@gmail.com )

Gradient-based routing in Wireless Sensor Networks: Jabed Faruque( faruque@usc.edu )

Instructor: Dr. Helmy2/5/2007

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CIS 6930: Workshop IWireless Measurements

Presenter: Shao-Cheng Wangshaochew@ufl.edu

Instructor: Dr. Helmy2/5/2007

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Agenda• Introduction

• Wireless measurement fundamentals

• Tools

• Assignment questions

• Reference

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How does a coverage map look like?

http://www.ittc.ku.edu/wlan/images.shtml

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coverage maps (cont’d)

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Wireless fundamentals: SNR v.s. Distance

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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)

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Tools• Site-surveyer: Netstumbler (www.netstumbler.com)

– Signal (in –dbm), SNR– AP MAC, SSID

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Tools (cont’d)• HP iPAQ

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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

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Lab Assignment• 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– Locate APs in some specific areas/buildings– Create an AP-specific coverage map– Observations and discussions about the AP planning (evaluation

of planning, tradeoffs, applications, etc.)

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Lab Assignment (cont’d)• Bonus questions

– Other types of maps? (e.g. war-driving)– Other points of interest (e.g. downtown Gville, oaks mall)?

(http://www.digitaldowntown.net/)– How to improve visualization? (http://www.sketchup.com)– How to automate the measurement procedure? (e.g. using campus bus

to survey wider areas?)

• Logistics– Lab #1 starts this week, due 2/26 (3 weeks from today)

• Come up your plan soon, feel free to discuss with me and other a-group members (email, appointments..)

– Come to CSE401 to check out equipments if you want• iPAQ 2400 (with Wi-fi, bluetooth built-in) • iPAQ 3900 (with gps, bluetooth built-in) *checkout by “per group”, send email for appointment before you come, bring

your id. *no overnight loan. everything should be returned by 6pm

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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