Schadenfreude: WiFi 5GHz on DFS channels

hwzlite

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Here's the site survey from my humble neighborhood far from airport/weather radar station:

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Mosts hogged at lower channel 42 @ 80Mhz, prolly due to using the default-plug&play auto channel selection which usually tries to avoid DFS channels. :s22:

Wi-Fi-Channels.jpg



Enjoy while I can now until my neighbors upgrade to shiny WiFi6 (802.11ax) @ 160Mhz device :D

Refs:
- http://wifinigel.blogspot.com/2018/05/the-5ghz-problem-for-wi-fi-networks-dfs.html
- https://dongknows.com/wi-fi-6-explained
 
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xiaofan

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I live in a corner unit and maybe the thick wall (1998 HDB block Jurong area) is very good at blocking 5GHz signal, so you can see it is pretty quiet for 5GHz, but 2.4GHz is really bad.

Now I just let the Asus RT-AX82U to select channels automatically including DFS channels and it is using CH60.
Edit to add: the app linked by the TS does not seem to work on my Huawei P20, so I use another app.
fVDIDMt.jpg
 
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firesong

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Like Xiaofan, my home in Bedok is a 1970s era unit, and the walls are thick enough to reduce most 5Ghz signals from neighbours. There are a few (probably immediate neighbours), but nothing like the 2.4Ghz band. The 2.4Ghz band is so congested, I can even get signals from across my block.

This is also why I'm eagerly waiting for the 6Ghz band to become popular. It should be good enough for fast internal networks while being properly contained by the walls without much cross-interference, reducing the occurrences of CSMA/CD and hence providing and even better home wireless experience.
 

xiaofan

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List of Wifi channels
https://en.wikipedia.org/wiki/List_of_WLAN_channels

IMDA Standard for TX power limit
https://www.imda.gov.sg/-/media/Imd...ion-Standards/Radio-Comms/IMDATSSRD.pdf?la=en

1) Max RF output power (TX power)
2.4000 – 2.4835 GHz: ≤ 200 mW (e.i.r.p)

5.150 – 5.350 GHz:> 100 mW (e.i.r.p.) and ≤ 200 mW (e.i.r.p.); DFS and TPC for 5.250-5.350GHz sub range

5.150 – 5.350 GHz: ≤ 100 mW (e.i.r.p.), DFS for 5.250-5.350GHz sub range

5.470 – 5.725 GHz: ≤ 1000 mW (e.i.r.p.), DFS and TPC

5.725 – 5.850 GHz :<=1000mW (e.i.r.p.). If > 1000 mW (e.i.r.p.) ≤ 4000 mW (e.i.r.p.); Operating under this provision shall be approved on an exceptional basis.

2) Max Transmitter spurious emissions
All frequency bands used by WiFI are >1GHz, so the limit is the same: <=-30dBm
 

yusoffb01

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5Ghz is quiet for me. signals from same router
qXkCGHM.jpg
 

hwzlite

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...so you can see it is pretty quiet for 5GHz, but 2.4GHz is really bad.

but nothing like the 2.4Ghz band. The 2.4Ghz band is so congested, I can even get signals from across my block.

& to make matter worse, some dude even config 2.4Ghz @ width 40Mhz channel which really makes no sense :s22:...
 

Mach3.2

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Interesting, is it by design sharing same channel?
Any chance config other using non-conflicting channel?
Unless his AP have multiple 5GHz radios, he can only broadcast all his BSSID on a single channel at any one time.
 

ahtionginsg

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I found channel 36 has the best signal quality and download speed, even it looks congested from wifi analyzer. channel 52 has no congestion, but my download speed on my laptop (intel ax201) dropped from 800+Mbps to 200Mbps at 2 meters away from the router comparing to channel 36. Phone not affected though. Router is ax82u and ax86u mesh.
 

xiaofan

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I found channel 36 has the best signal quality and download speed, even it looks congested from wifi analyzer. channel 52 has no congestion, but my download speed on my laptop (intel ax201) dropped from 800+Mbps to 200Mbps at 2 meters away from the router comparing to channel 36. Phone not affected though. Router is ax82u and ax86u mesh.

Interesting. But yes signal strength and speed may not always be correlated.

I am using auto (including DFS channels) settings for the RT-AX82U China version (2.4GHz disabled, only 5GHz), it is using CH60 now. My 3 years old Acer Swift 3 laptop with upgraded Intel AX200 adapter is pretty fine with the AX82U at 3m range (600Mbps - 800Mbps+).

It may be related to the location as well because CH52 to CH64 are DFS channels. For example if you are closer to the airport, maybe it will affect the operation.
 

hwzlite

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Muhahahaha.. site survey at the playground surrounded by HDBs.

Screenshot-2021-01-31-21-08-54-074-abdelrahman-wifianalyzerpro.jpg
 
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