Science Buddies: "Ask an Expert"

Hi everyone,
I am a frazzled parent who has been researching how to read the dBm strength from a router to an iphone. I cannot seem to find any application for any Apple product that measures wi-fi strength this way. I am about to hijack a fiber optics truck and see if they have a little gizmo that reads that way!
Any advice would be great. Oh, I have already found the code to the Field Test page on the iphone which supposedly gives you the dBm instead of bars in the upper left hand corner. The problem is, I have not gotten any reliable results from our experiments. My 7th grader has no fear of failure, but I do! I want this to work.

Hi,

Take a look at this site:

http://www.mirazon.com/5-phenomena-that ... fi-signal/

Pay close attention as how you are increasing the distance from the source. Ideally on open space would be best. I have to assume that the iPhone measurement is right and that somehow your signal is being affected in other ways. The expected answer is clear: The power should drop with distance.

Also, make sure you are not confusing cellular signal strength with wi-fi signal strength. Cellular phone to tower communication is such that your phone hops from tower to tower seamlessly.

It's not obvious from your post if you can use your iPhone to measure dBm? looks like yes?

Note: You can make a very similar experiment using sound and decibels. There are phone apps that measure dB (decibels).

Let us know how it goes. Good luck!