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The Point of a Parabola

Postby proteindenaturation » Sat Nov 16, 2019 11:29 pm

Hi! My 6th grader is working on the "Point of a Parabola" project, but couldn't find a site that measures in dBm. Using the recommended WifiInfoView program, he used the "Signal Quality" readings to complete his experiment. What is the label for this data? percent? Is signal quality a scale from 1-100? He began with 59 "signal quality" without a parabolic reflector. This number increased to 78 "signal quality" as the highest amount we could get using the reflector. We have a 30 foot distance between the router and laptop. It was obvious that the signal quality changed with different tests we performed, so we hoped measuring the change in signal quality would work. How do we label signal quality in our graph? Is it a percentage? if so, a percentage of what specifically? Just wanting to make sure we understand and label the measurement correctly.
Thank you so much!

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Re: The Point of a Parabola

Postby AmyCowen » Tue Nov 19, 2019 9:38 am

It sounds like your student's tests were successful in showing differences in signal quality.

In step 2.b of the "Testing Your Parabolic Reflector," this is noted about the scale of signal strength:
"Make sure you know how to measure the wireless signal strength in dBm. As explained in the Introduction, the dBm readings should be negative numbers. Some programs may provide other scales — for example "signal quality" on a scale of 0–100 — but you should use dBm if possible. If dBm is not an option at all, then it is OK to use "signal quality" instead. You may need to read your program's documentation or help files, or ask an adult to help figure this out."
[Project information: ... background]

I searched, and there is information on the support page for the program you used which may be helpful to your student in understanding the data gathered and putting together the graphs and display board.

There is a glossary of terms for the program at the bottom of this page: ... _view.html

According to that information: "Signal Quality: A number between 0 and 100 that represents the quality of the signal."

And, also note: "RSSI: The received signal strength indicator value, in units of decibels referenced to 1.0 milliwatts (dBm), as detected by the wireless LAN interface driver for the AP or peer station."

I hope this information helps.

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Re: The Point of a Parabola

Postby proteindenaturation » Fri Nov 22, 2019 8:55 pm

Thank you!

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