tamograph site survey - university of california, santa...
TRANSCRIPT
TamoGraph Site Survey
Adrian Oleksiewicz
CE 158 w/ Brad Smith, Jim Warner
Spring 2012
TamoGraph S.S. introduction
Wireless tool for collecting, visualizing, and
analyzing 802.11 a/b/g/n Wi-Fi data.
Three surveying methods:
Continuous, point-to-point, GPS
Two survey types:
Passive Survey (complex RF analysis, dBm)
Active Survey (UDP, TCP etc. throughput)
Why perform Wi-Fi site
survey?
Time consuming, complex tasks…
Analysis and reporting of: signal strength,
noise and interference, channel allocation,
data rates, etc.
Make sure there is complete coverage of
building.
Steps for getting ready to survey
1) Acquire laptop with proper network interface for doing
passive/active surveys. (tablet).
2) Acquire floor plans to building (thanks Jim)
3) Create eduroam account (all Wi-Fi interfaces)
4) Open Software. Project -> New Project
5) Select building environment (attenuation)
Steps (continued)…
6) Select channels to scan (2.4gHz 1-14,
5gHz 8-196)… (less = faster scan per
channel)
6) Load floor plan and calibrate map
distance:
Steps (continued)…
7) Now you are ready to begin survey…
- Select survey mode
Steps (continued)…
8) Plan the path you will walk
9) Walk at a steady pace and tap the map
whenever you change direction.
10) When area is sufficiently covered, stop
survey and now you can analyze the results.
note: Special building access to locked
rooms.
My Results (Science Engineering Library)
3 Floors.
Not very many closed off rooms, large spaces.
9 Access Points total
First Floor – Passive – Signal Strength
Second (main) Floor – Passive – Signal Strength
Third Floor – Passive – Signal Strength
Results
Fairly good coverage in the areas that require
Wi-Fi
Signal Bleed Through – First Floor (only showing signal from Second)
Signal Bleed Through – Second floor –
(left = bleed from 1st floor, right = bleed from 3rd floor)
Signal Bleed Through – third floor- signal from second floor
Results
Don’t count on using APs from other floors to
fill in any dead spots on current floor.
Surprisingly, bleed through was stronger
coming from ceiling than floor, despite APs
being farther.
Active Surveys
Unreliable (because of computer
drivers/roaming handling)
Blank Spaces
Missing APs
Active Reliability/Consistency Test (Two Runs, floor 2) – TCP downstream rate
Results: One AP was running much faster on a second run through, slightly
inconsistent
Active Reliability/Consistency Test (Two Runs, floor 3) – Actual PHY rate
The physical layer (PHY) rate is the speed at which client devices communicate with the AP
Limited speed because of WiFi dongle speed capability (?)
Passive Survey Consistency Test – Second Floor- Signal Strength
Note: right image does not contain survey of special access/locked areas
Passive Survey Consistency Test – 3rd floor – signal strength
Results: Passive surveys are pretty accurate/reliable.
How long does it take?...
Constantly learning the software. But after 3 good
runs, and playing around with the APs you should
have a good understanding. (2-4 hrs)
Each run in the library took about 5-10 minutes.
Recommended two or three passes to make sure
there is consistency.
Depending on reliability of wireless card (and active
surveys), Science and Engineering Library would
take roughly 30mins-1.5hrs to survey.
Issues I ran into doing this project
Getting laptops (took ~4 weeks). + another
week for installing memory.
Active Surveys.
Connecting + Staying connected to internet
(happening at home as I make this
presentation) … buggy laptops/drivers (?)
Setting up Eduroam on 2 Wi-Fi cards.
Heavy laptops (esp. w/ extra battery pack).
Issues continued Combining files into one project:
"Create a new project and calibrate the map. Save the project and copy the project file to the portable computers that will participate in the data collection process. "
So in order to combine floors into one tamograph project file, the "seed/basic" file must be initially distributed between the computers/project (?) ... or else "no matching site map" error [image]
Conclusions
Science and Engineering Library has great coverage.
I would recommend this software.
More up-to-date hardware/tablets.
(Test to see if it removes the issue roaming/active survey issue).
Thanks for listening! :]
