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So I know all about using channels 1, 6 and 11 as non-overlapping channels for 2.4 GHz wireless but does this rule still apply when living in a large apartment complex where everyone uses 1, 6 or 11 and probably stream video all day? I recently have had trouble with my two iphones and wireless printer trying to connect to my wireless router. My phones started saying unable to join network and printer wouldn't connect either. I tried all combinations of things I read on the internet and none of them were working. I changed my 2.4 GHz channel from auto to 6 (which had the fewest users but I have no idea how much they are using) and that didn't help but when I changed it to 8 everything started working as it should.

I am using an Airport Extreme router. Does this make sense that 8 would work better?

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Just get a 5.0 Ghz router it solves all your problems there is no software or hardware solution to crowed radio space –  Ramhound Jul 5 '13 at 1:32
    
By using 8, you're overlapping both 6 and 11, likely making things worse for everyone. –  David Schwartz Jul 5 '13 at 12:56

3 Answers 3

Find a wifi scanning app on your phone and see what channels are being used in your nearby area. If everyone is using 1, 6, and 11 then the channels in between will likely not have that much strength.

Think of bell curves with 1, 6, and 11 being the top most point. As the signal reaches channels 3 and 4 or 8 and 9, the signals for the ones broadcasting on 1, 6, and 11 become weaker. If you were to use a primary channel of 3/4 or 8/9 then the highest strength of your signal will not overlap with those other wifi networks.

Now if other people are also running non-standard channels, then you will need to try to find the one that is the least polluted by other wifi networks, which is where the Wifi scanning app comes into play.

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Find the clearest channel and use it. It's where smart phones and android pads have a definite strength. We used to have to buy special dongles and spectrum analyzer software to do this. Look for all the clumps and place yourself in between the clumps. A single AP on Channel 5 can beat out 25 systems all glued on 1,6,11. –  Fiasco Labs Jul 4 '13 at 21:16
    
There are about 20 people using channel 11, 15 for channel 6 and 5 people using 1. There are also a few people using 9+5 and a few using 10+6. I will try channel 1 since it has the fewest. –  Todd Hoefen Jul 4 '13 at 23:56

The router's channel also sees what is called a noise floor. This varys from router to router channel to channel. I try to use a channel with a lower noise floor which would also necessarily be less used. A lot of things can cause noise on a channel. With a lower Noise floor you are likely to have a higher signal. Signal - to - noise ratio, that is key, getting your signal as high above the noise as possible. signal and noise are measured in db and are mostly negative numbers least negative being a higher signal signal to noise is measured in positive numbers of db , higher being better. Find a channel with a low noise floor. It also helps to be running a router that packs a punch a higher power output means that your stations will hear the router better. Router power output is usually rated in db as well and usually anything above 21 db is good. 21 db would be about 125 milliwatts. in my book I want something producing at least that much, 500 0r 600 is fine if you can afford it. bigger antennas is sometimes better than more power cause they are rated in db as well and the higher the number the more signal both directions...

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802.11 uses spread spectrum modulation: it spreads the signal by a specific pseudo random code to send the data and de-spread the signal by using the same code. enter image description here

so the transmitted signal from a wifi decide is on the noise level for another device. So it should not effect how many people around you use the same frequency unless there are hundreds of them around you.

Therefore, it does not make sense that WiFi work better at channel 8.

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In theory, it's supposed to work this way. You're better off finding a relatively open channel with minimal overlap. We've been making sense of the nonsensical in using any free channel since smart phone spectrum analyzer apps came out. It makes a major difference if you're not one of 14 stations trying to use channel 1,6,11 to increase your throughput. What is never taken into account is hidden transmitter effects where pairs of stations don't have complete symmetrical receive/transmit visibility between their locations. –  Fiasco Labs Jul 4 '13 at 21:22
    
Your are right that would effect the throughput but I doubt it would jam an Access Point, especially they are at noise level signals. At my work place, I count around 20 APs around me uses the same frequency that my WLAN does, and I have no problem with my AP which is 50 meter away from me. –  angs Jul 4 '13 at 21:31
    
As I posted below there are a number of people using all of the channels. I will try channel 1. I guess I did post this question because I also don't understand why I can use all of my devices on channel 8 but not on 6? I have tried everything else. Upgraded firmware, downgraded it to an older version to see if that worked, reset the router, reset the modem and so on? –  Todd Hoefen Jul 5 '13 at 0:00
    
Other WLANs should not effect you as spread spectrum is a very robust modulation technique. if you are a Linux user, can you paste iw list output –  angs Jul 5 '13 at 0:09

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