The fight for 2.4 GHz Wi-Fi Spectrum - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: December 12, 2017, 08:48:51 am
content: I've just spent the past few hours configuring 3 new Ubiquiti Wi-Fi access points, which involved a lot of testing for interference and busy channels taken up by nearby access points and other devices.While the 5 GHz band is reasonably clear (I can have at least 3 non-overlapping 80 MHz channels all to myself), the 2.4 GHz band is far from it (but we knew that already).I'm lucky enough to live in a regional area, so the number of "interfering access points" in the 2.4 GHz band is limited to about 7 at any given time as I walk around the house, however some douche has decided to configure his Wi-Fi router to take up 40 MHz (essentially channels 5 to 13) rather than sticking with the conventional 20 MHz (which would probably yield him better performance, see why below).I don't know about you, but people who don't understand technology just shouldn't fiddle with settings (I now see why most APs/consumer routers come with an "auto channel" function).So I conducted a little experiment, I configured one of my access points to use Channel 1, ~2412 MHz because it's the furthest away from the centre frequency of a microwave oven and manually ramped the power up to the maximum legal limit.After a little while, the neighbouring access points that were occupying Channel 1 (and 2 and 3) have jumped over to "less congested" channels (as seen in the attached screen shot). Now douchy-mc-douche-bag (the grey parabola) has a bunch of other networks to deal with since he decided to be greedy, while I have a clear channel (yellow and dark blue parabolas).Am I being mean? Surely I can't be alone in this.While most of my devices use 5 GHz, not all of them support it.

author: Kjelt
author_rank: Super Contributor
timestamp: December 12, 2017, 09:01:00 am
content: You are making an assumption that your neighbour on purpose configured his device.From experience there are many devices sold in the past that occupy the entire 2,4GHz band, one of them is a wireless video transmitter, it transmits the old analog videosignal to the bedroom way before any Wifi device was invented.If you ever stood on an exhibition with a demo in that band you know it is Mission Impossible 7.That other protocols and applications such as bluetooth and Zigbee also use these bands does not helpThe only real solution is freeing up more bandwidth from other old fashioned/obsolete purposes.

author: Halcyon
author_rank: Unknown
timestamp: December 12, 2017, 10:28:12 am
content: Quote from: Kjelt on December 12, 2017, 09:01:00 amI make the assumption based on the following:- I'm yet to come across a consumer Wi-Fi modem/router that defaults to a fixed 40 MHz on a 2.4 GHz band (he is using a Billion modem/router according to the MAC address). Some will have an "auto" mode where if the band is clear, it will switch from 20 to 40 MHz automatically.- The parabolas shown in the screen shot are all from Wi-Fi devices. This software doesn't detect other (non-Wi-Fi compliant) devices, so anything else in that band (Bluetooth, baby monitors, AV transmitters) are not shown at all. For those I used a spectrum analyser.Based on those two factors alone, I can be 95% confident that it was done intentionally.

author: borjam
author_rank: Unknown
timestamp: December 12, 2017, 11:28:47 am
content: Quote from: Halcyon on December 12, 2017, 10:28:12 amVodafone in Spain configured their residential customer routers with 40 MHz channels at least for a while. Not sure what are they doing now.

author: Unknown
author_rank: Unknown
timestamp: December 12, 2017, 11:48:51 am
content: Quote from: Halcyon on December 12, 2017, 10:28:12 amPlenty of Billion gateways sold here came configured out of the box for 20/40MHz andreallyliked to camp out across 40MHz beyond all reason - I've seen them stubbornly trying to keep using the whole lot while throughput dropped to near-0. They were a right pain in the proverbial back when I was dealing with such things...