About to pull my hair out -- wireless interference?

[SimbaLion]

Until about a year ago, I've been happily chugging along with a Zyxel X550 wireless router. Fast speeds, never crashed. Loved it.

My place isn't that big -- it's a house with 2 floors, and the router is on the bottom floor towards the back. I have devices on the upper floor (Tivo, iPad, and a laptop) that I use and they're towards the front of the house. Like I said, it's not a big place -- probably 75ft ft from the front to the back of the house, if even that.

About a year ago, I started being unable to reliably connect to the laptop on the top floor. Signal strength fell from 4-5 bars to 2 bars and I basically stutter my way through web browsing.

Long story short, I thought it was my router, so I started upgrading -- tried a Zyxel X550n (didn't get any better of a connection), a Netgear 3700 (much worse than any other router I tried in terms of speed and interface), a Buffalo "Hi Power" N router, an Asus N16 (both stock and Tomato firmware), an Apple Airport Extreme WITH an express for bridging, and finally, a Linksys e3000 (which is what I still have...)

The e3000 seemed to work brilliantly for a while...fast speeds, good connection. Then one night, it dropped to two bars again. I installed iStumbler on the laptop and it shows horrendous Signal to noise ratios whenever I have these weird signal degradation issues.

What is causing this interference?? Is there any way to combat it? I basically have no clue how to "fix" this...

 

[stevech]

may not be interference.... because a reduced signal strength indication on the client side doesn't match an interference issue.
I'd consider these possibilities
1. Client device is, now and then, switching away from your WiFi and associating to a neighbor's open/unencrypted WiFi. Watch the client's behavior for this.

2. The client's transmitter power degrades, or if it's battery powered, its power-saving mode of WiFi is not working properly (the router must cooperate for this mode). Ideally, but often not, the router will display the received signal strength for each client.

3. Try changing channels on the router, among, 1, 6 and 11 (in 2.4GHz).

 

[SimbaLion]

Thanks for the reply --

I'd consider these possibilities
1. Client device is, now and then, switching away from your WiFi and associating to a neighbor's open/unencrypted WiFi. Watch the client's behavior for this.

Though I have seen an exploding number of access points around me, I am 100% certain that my laptop has been connecting to my own.

2. The client's transmitter power degrades, or if it's battery powered, its power-saving mode of WiFi is not working properly (the router must cooperate for this mode). Ideally, but often not, the router will display the received signal strength for each client.

I actually thought this was the case too (thinking my laptop's wifi card was going bad), but when the signal issues occur, the iPad can't even connect at all to the Wifi signal, so it's not just the laptop's hardware.

3. Try changing channels on the router, among, 1, 6 and 11 (in 2.4GHz).

I've also tried this. Sometimes it helps a little, but more often than not, it doesn't do much.


Any more clues?

I really appreciate your time in helping me think through this.

 

[stevech]

what does iStumbler display when you are having the issue, versus when not?
Interference would cause reduced throughput/speeds rather than reduced signal strength, as a general rule.

 

[Runamok81]

Does it happen during certain times of day? Or is it something more permanent? Do computer reboots or router reboots impact the issue?

 

[thiggins]

Invest $100 in a Ubiquiti PowerAPN and use the AirView Spectrum Analyzer tool to see what's really going on. It will let you see if your AP power is really dropping and also if there is general RF noise.