Edit: Wireless Access Points, not Modems
I read some time ago that overlapping interference is a lot worse so all modems should use either 1, 6, or 11. But I see a lot of modems in my neighbourhood using all the channels from 1-11, causing an overlapping nightmare. Why do modem manufacturers allow overlapping to happen in the first place?
Edit: To clarify my question, some countries allow use of all channels and some don’t. This means some countries’ optimal channels are 1, 5, 9, 13, while other countries’ optimal channels are 1, 6, 11. Whichever the case, in those specific countries, all modems manufactured should be hard limited to use those optimal channels only. But modems can use any channel and cause overlapping interference. I just don’t understand why modems manufacturers allow overlapping to happen in the first place. The manufacturers, of all people, should know that overlapping is worse than same channel interference…
To add a scenario, in a street of houses closely placed, it would be ideal for modems to use 1, 6, 11. So the first house on the street use channel 1, second house over use channel 6, next house over use channel 11, next house use channel 1, and so on. But somewhere in between house channel 1 and 6, someone uses channel 3. This introduces overlapping interference for all the 3 houses that use channels 1, 3, 6. In this case, the modem manufacturer should hard limit the modems to only use 1, 6, 11 to prevent this overlapping to happen in the first place. But they are manufactured to be able to use any channel and cause the overlap to happen. Why? This is what I am most confused about.
In: Technology
Can someone explain this question like I’m five?
Almost touches on the idea of a prisoner’s dilemma -like situation.
The standard allows the choice of any channel in the range to best suit the user’s wishes. But let’s just say everyone sticks to 1/6/11 and those three bands are heavily congested. Anyone setting up a new radio in a congested area will find a LOT of interference centered around each of those three channels.
Someone else gets tired and decides that to avoid interference he should select something in the middle of the overlapping bands like channel 3. And suddenly now you have someone who has a relatively clear channel, but now 1 and 6 have some interference from another channel in addition to everyone else already on 1/6.
Other WiFi devices aren’t the only thing that you might need to work around, it could be other 2.4ghz devices as well as environmental factors.
because with channels 1, 5, 9, 13 you get 4 non overlapping channels. not all countries allow all channels.
Because in much of the world world, you should be using 1, 5, 9 and 13, to get 4 non overlapping options. The 1-6-11 is used because of the U.S. refuses to allow use of channel 13, or, in Japan, to allow channel 14 to be fully non-overlapping.
In addition, there are uses for half-overlapping channels. When a large area needs to be covered, you have 3 non-overlapping channels nearby, and further away you use half-overlapping channels, where the weak overlapping signals won’t cause as great a problem.
so if i enable only those channels i will benefit from it because other people use the standard settings ? if so, how do i do that ? thanks
Because that isn’t how wireless signal works.
https://cdn.comparitech.com/wp-content/uploads/2018/03/16-2.4G-Channels-1024×587-1024×587.jpg
The farther you are from the center of another network’s broadcast, the less noise that network causes. If you have 9 networks in range, you will do better with partial overlaps on 4 of the other networks, than you will with complete overlap with 2 other networks.
Two reasons: edge cases where it does make sense to deploy on one of the normally overlapping channels (think single AP deployments in odd RF environments), or other countries where you’re allowed to go up to channel 13.
Cause number 1: Freedom.
Number 2: FCC actually had a rule saying you can only use 1,6, and 11. But no one had to follow it, and it’s left open to use whatever channel you want because there is/was anticipation to use wider band channels (40mhz over 20mhz for OFDM). Which you can see in the wild if you have a scanning tool. If you’re curious, you can get Alfa Wifi Scanner software and take a look at the different channels are being used in your area and what their bandwidth is. From that, you can also choose a better channel for you personal device.
This is a really smart question for a five year old.
I know it’s just semantics but you’re referring to wireless access points (WAP). Not all modems perform as routers and access points.
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