Channel selection

[I_Terrabull]

I live in NYC. Due to the overwhelming number of APs, good channel selection is difficult. I know that 1,6,11 are the optimal channels, but no of these seem workable in my situation.

One of my neighbors has his router set on channel 3 and it seems to be overwhelming the area. Channels 1-5 are rendered pretty much useless. I have no idea who this 'Grahame' is.

I set my channel to 10 since Wifi Analyzer gives it the highest rating. What can I possible do to make this a better situation for myself and my neighbors.

I've included Wifi Analyzer and inSSider screenshots.

 

[thiggins]

Best thing is to move to the 5 GHz band if possible.

The best method boils down to trial and error. This post basically summarizes the approach.

Good luck.

 

[stevech]

It's likely that WiFi Analyzer is showing WiFi SSIDs that exist.
That's not very important.
What does matter is which of those carries a LOT of traffic, and when.

 

[tipstir]

WiFi does get crowded if you live in heavy WiFi usage area. 2.4GHz seems crowded you can go with the suggestion of using 5GHz instead. 802.11ac around the corner another option to try. Use that software you have to scan who can what and try to but a different brand for Wireless. I had ran into some issues with my CISCO E4500 with one next door house is using something CISCO same channel same power level. Odd that has knocked me off and disabled my network media players. Also E4500 started to give issues again one of the RE1000 has failed dropped off the network on it's own. The other one won't connect to the EA4500. I had to switch to EnGenius XtraRange ESR600H which I had use for testing. Latest firmware fixed a lot of prior bugs in it now works as my primary WNAP (WAP).

 

[claykin]

I have no idea who this 'Grahame' is.

I'd guess that Grahame lives VERY close to you judging by his signal strength. Do a little walk around the floor/building and see if you can identify him. -46db on 2.4Ghz means you are pretty close to the source antenna.

Are you working OK on channel 10? If so, leave it alone. Alternative is to move to 5Ghz as others stated.

 

[I_Terrabull]

Thanks for the replies.

Today I'm scanning the APs and 'Grahame' is now on channel 6. I guess he has some sort of auto channel selection on the router.

It's probably time to ditch the westell wireless router(VZ DSL). I feel like I'm in an arms race with my neighbor and need a good high powered AP to 'compete'. Any suggestions?

 

[sfx2000]

all you need is about 20dB difference with an adjacent Access Point - not that much different that planning out an enterprise deployment in a medium sized building.

 

[stevech]

all you need is about 20dB difference with an adjacent Access Point - not that much different that planning out an enterprise deployment in a medium sized building.

What's the reasoning for this? 802.11 is CSMA/CA. Channel sharing by listen-before-transmitting. Energy in or near (3 channels) of your operating channel will delay your transmissions. Good for sharing. If heavy traffic, not good for optimal latency and throughput. Such is life in unlicensed bands.

 

[tipstir]

Today you can buy 20dBm, 23dBm, 27dBM and 30dBm. But the higher the number doesn't mean you'll be all set. Fallback always been 20dBm. 23dBm 200mW and the 20dBm 100mW. Most of the known major players seem to go lower from 14dBm to 18dBm and then force you to buy many repeaters to make up the different in signal.

Motorola has AP650 for $199 but requires additional wireless RF switch hardware AP650 has 24dBm with adjustable TX setting by 1db 2Tx3R design.

 

[stevech]

You're mixing dB and dBm. (dB is a ratio. dBm is a measure of power, where 0 is equivalent to 1 mW).

The statement above was
"... all you need is about 20dB difference with an adjacent Access Point..."

To me, this is saying your WiFi signal needs to be 20dB (or more) stronger than an adjacent Access point. As if that's enough to "overwhelm". Maybe I misunderstood. I brought up CSMA/CA because in 802.11, things usually work correctly: two devices rarely transmit simultaneously causing a collision. When it does happen, rarely, a 20dB SINR (signal to interference + noise ratio) can arguably work for certain modulation rates. If that's what is being said.

If WiFi gets in to a power war, it'll deteriorate as did Citizen's band radios.

 

[sfx2000]

You're mixing dB and dBm. (dB is a ratio. dBm is a measure of power, where 0 is equivalent to 1 mW).

The statement above was
"... all you need is about 20dB difference with an adjacent Access Point..."

To me, this is saying your WiFi signal needs to be 20dB (or more) stronger than an adjacent Access point. As if that's enough to "overwhelm". Maybe I misunderstood. I brought up CSMA/CA because in 802.11, things usually work correctly: two devices rarely transmit simultaneously causing a collision. When it does happen, rarely, a 20dB SINR (signal to interference + noise ratio) can arguably work for certain modulation rates. If that's what is being said.

If WiFi gets in to a power war, it'll deteriorate as did Citizen's band radios.

Well, more power is never the answer in wideband communications

20dB is enough above the noise floor, and adjacent AP's are just that, noise, that 802.11 can work. This is all RF and PHY - less than 20dB, it really starts to affect the CNR (correlated signal to noise ratio), and you'll start seeing increased framing errors, and likely drop to a lower order modulation scheme, in lay terms, you'll slow down.

Don't confuse MAC with PHY - the CSMA/CA is a MAC function to detect and resolve collisions within the service set - same with the CTS/RTS mechanisms to ensure that the air is clear when transmitting.

The reality of 2.4GHz in the urban environment is you'll likely never have a perfect channel, so using tools like Innsider can be helpful to find a channel that generally works.