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
Also why the hell when I choose auto channel selection the router chooses the WORST channel and basically never chooses 1,6,11?
I know it’s just semantics but you’re referring to wireless access points (WAP). Not all modems perform as routers and access points.
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.
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 with channels 1, 5, 9, 13 you get 4 non overlapping channels. not all countries allow all channels.
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.
The decision to restrict 802.11 to a 72Hz range was a stupid one to begin with. The overlapping channels thing is a mitigation of that. I can imagine the standard changing to what you described, and it would help for some people but it’s just mitigation on top of mitigation of a screw-up that needs to be fixed directly. Also, restricting to those three channels reduces flexibility for people who need to fine-tune things to avoid interference from things other than WiFi.
All these answers and not a single person has stumbled on the correct one: Hindsight is 20/20.
Remember that when the standard was settled upon, the designers had absolutely no idea how ubiquitous WiFi would become. It would be approximately another ten years before WiFi routers would even start to become household appliances. Zip drives were state-of-the-art, laptop thickness was measured in _inches_, and the concept of a smartphone was about a decade away from public consciousness. People rented VHS cassettes to watch movies at home on their rear-projection TVs, and HD television was for the idle rich. Netflix had just started mailing people DVDs via The Postal Service.
Okay, I’m getting a little carried away describing the world of the late 90s, but it’s important to remember the designers of the 802.11 standards had to make choices in a world where households rich enough to even have internet access connected to the internet via dialup. No one even conceptualized a world where routers would be so cheap that every single tenant in an apartment building would have their own radio transmitter sitting in a closet gathering dust out of sight, out of mind. Many of the choices they made for the standard naturally assumed wireless internet access would only really be deployed by professional network admins who would have control of all the other routers in range. Why not let them choose any channel?
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.
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.
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