Geek: omgwtfbbq my wifi reaches the 1st floor (in a way)
Saturday, October 27, 2012

So... I was walking home today. My phone (Samsung Galaxy S2) happened to have it's wifi turned on. When I passed by a playground nearby, I suddenly realized that my phone is connected to a network. I quickly opened up the settings to check if I connected to a random open network. I am paranoid and I'm afraid someone is trying to hack it or anything.

Lo and behold! I was connected to my room's wifi connection. I am roughly 33.7 meters away from my room. Using rough estimates of my apartment's height and distance from the block, calculated using Pythagoras theorem. (it is finally useful in something practical)

Holymotherofballs. I couldn't believe that actually happened. I'm sorry for not having screenshots, I'll do some testing another day so bear with the wordy representations.

Connected with a good link, probably with 40% strength. Hovering 15~26mbps bandwidth. Ran a speedtest, which thankfully has it's results saved in my phone.



The first results on top, 7.26mbps down, 6.91mbps up. I could maybe get a stable 1MB/s download if I tried positioning myself a little better. (note the amazing 12ms latency)

How does this happen? 2 things mainly.
Line-of-Sight and Fresnel Zone. 

My room was facing towards the location I was coming from, with only 1 wall separating the connection, I have a decent enough LOS. There weren't any trees or EMI materials blocking the "zone" where the connection is made. I've also configured my router to be pumping up at the maximum legal limit of 100mw through it's antennas. It's a low gain 3dB antenna so it could actually be a lot better once I've changed them.

Also, because I could walk anywhere I wanted, I can finally observe the "shape" of the signal outputted by an omni-directional antenna.

It was extremely amusing to see the things I learned last year being put into practice. I suddenly gain a new perspective on a lot of things that I've been spending my time reading. I don't really know how to put it into words but it's like, things just made a lot more sense to me right now.

I was so excited I started calling up my friends and telling them about my discovery. I am so pumped with motivation I want to get so much equipment and start experimenting with them all around the place! It's like, finally something geeky that I could do outdoors! This is definitely a first for me who's used to staying cooped up inside the room while doing my own "research/studying". One of these days, I'm going to bring my laptop down and start doing some tests of my own.

Though everything is great and amazing, I noticed something worrying. What I've learned in school is that you should never allow your wifi to extend to places you don't intend to be used, for security reasons. Yet, almost anyone could get a lock-on on my signal, even from hundreds of meters away if they used the right equipment. This is definitely worrying for me.

Also, I am sorry to all the residents around here. Even though I picked up a lot of signals while I was downstairs, I definitely noticed my signal even though it's broadcasted from very far away. I am probably affecting some unfortunate person's wifi signal. I will try to reduce interference once I'm good enough at this, so till then, I shall keep experimenting with things like these!

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