Question Wi-Fi interference (not used signal)

[cambridge1234]

Will an active AP that is not connected to any device will cause interference with another one operating in the same channel/.frequency? In other words, if I have 2 wireless routers at 2.4GHz and only 1 has devices connected, will turning off the one not in use make the other one better in anyway. Or maybe another way to ask the question is , if interference is caused by simply having AP transmitting wifi signals in overlapping frequencies or a device needs to be connected and using bandwidth to create interference?

 

[kanewolf]

There are multiple channels in the 2.4Ghz band. Three channels have no overlap (1,6,11). If router A is on channel 1 and router B is on channel 11, there will be no interference. If both are on channel 1, but with different SSIDs then router A will broadcast (with no devices) and will have some small amount of impact on router B. WIFI is difficult to predict because of reflection and absorbtion of signals.

 

[cambridge1234]

There are multiple channels in the 2.4Ghz band. Three channels have no overlap (1,6,11). If router A is on channel 1 and router B is on channel 11, there will be no interference. If both are on channel 1, but with different SSIDs then router A will broadcast (with no devices) and will have some small amount of impact on router B. WIFI is difficult to predict because of reflection and absorbtion of signals.

Thanks!
I understand the concept of the non overlaping channels (1,6,11) but that only applies within 1 AP that you can control, if I select channel 1 thinking that it wont have overlap and my neighbor is using 2 or 3 it will overlap with the frequencies on my channel 1 so it will defeat the purpose.
In any case I think you answer the question by stating that even when there are no devices connected broadcasting wifi signals will have some impact on the router you want to use
Thanks again for your feedback

 

[kanewolf]

Maybe your original question wasn't clear on the situation. Obviously a neighbor's WIFI on the same channel (with THEIR devices) can interfere with your WIFI on that channel. This is why you need to move as many devices to WIRED and the remaining to 5Ghz where possible.

 

[bill001g]

Pretty much you have to give up and assume your are 100% overlapped with your neighbors.

You have to be careful about the so called channel numbers you see on the 2.4g band. Those only represent 5mhz of bandwidth and wifi used to use 20mhz so more or less 4 of what the router calls channels. There is 60mhz total bandwidth on 2.4g so in theory you can have 3 devices which is what 1,6,11 represent.

That is all old information. Almost everyone is using 40mhz channels, so it is now impossible to fit 2 40mhz signals into 60mhz of bandwidth. So no matter what channels you pick you are likely overlapped at least partially.

The 5g channels have a very similar issue even though there is more bandwidth.

The new so called wifi6 or802.11ax is suppose to have some new features to help resolves this but I have my doubts unless they let you control your neighbors usage in some way.

 

[kanewolf]

Pretty much you have to give up and assume your are 100% overlapped with your neighbors.

You have to be careful about the so called channel numbers you see on the 2.4g band. Those only represent 5mhz of bandwidth and wifi used to use 20mhz so more or less 4 of what the router calls channels. There is 60mhz total bandwidth on 2.4g so in theory you can have 3 devices which is what 1,6,11 represent.

That is all old information. Almost everyone is using 40mhz channels, so it is now impossible to fit 2 40mhz signals into 60mhz of bandwidth. So no matter what channels you pick you are likely overlapped at least partially.

The 5g channels have a very similar issue even though there is more bandwidth.

The new so called wifi6 or802.11ax is suppose to have some new features to help resolves this but I have my doubts unless they let you control your neighbors usage in some way.

@bill001g , I will say that since I have installed Ubiquiti APs with the ability to monitor neighboring WIFI, I don't see many 40Mhz users. Most neighbors in my part of the world are "good" neighbors and use 20Mhz on 2.4Ghz.