tamograph site survey - university of california, santa...

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! :]

Thanks for listening! :]

Adrian Oleksiewicz

aoleksie@ucsc.edu

760-705-5087