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Opened 2 years ago

Closed 2 years ago

#21365 closed defect (not_a_bug)

RaLink Rt3050 802.11bgn radio only works on 20Mhz

Reported by: yurtesen Owned by: developers
Priority: low Milestone:
Component: base system Version: Chaos Calmer 15.05
Keywords: 40Mhz 802.11n 20Mhz noscan Cc:

Description

I have been trying for a while to get it to work on 40Mhz but it just wouldn't. Until I consulted the forum and advice was to add noscan to config. Only, after adding noscan=1, the 40Mhz seem to work. Setting 40Mhz from luci does not add this option.

Thread:
https://forum.openwrt.org/viewtopic.php?pid=303430

Attachments (0)

Change History (5)

comment:1 Changed 2 years ago by user5077

This is perfectly normal. Openwrt will leave it to 20 MHz if it detects interference, unless you explicitly add noscan=1.

comment:2 Changed 2 years ago by yurtesen

I disagree completely. I can see the interference argument, but why? Other brand APs do not do this. I just put 3 APs next to each other, two of them were 802.1n 150Mbit and one 300Mbit. My windows machine got 150Mbit and 300Mbit(ehmm 2x 40Mhz!) connections to APs with original firmware. The OpenWRT does 72Mbit only.

This makes the whole 40Mhz unusable for almost everybody unless you live in an island alone or something. ;) If you have to do this, just remove the 40Mhz option altogether, make the UI easier to understand. Why bother with unusable options to begin with?

If you think there is a regulation for this. Please post the link to it. I never heard about it before, in either case apparently other manufacturers do not care about such things anyway.

Also this is a user experience problem more than a technical one. If a user sees 150Mbit connection but it works poorly due to interference, user would blame the interference. But if user sees a 70Mbit connection on a 150Mbit device, user would immediately think there is a fault in the device to begin with. As a matter of fact, I thought it was fault of OpenWrt simply because only OpenWrt had this problem.

Thanks!

comment:3 Changed 2 years ago by J1mbo

Answered in forum; hostapd implementation of BSS scanning per 802.11 (2012) 10.15 (20/40MHz BSS Operation) prevents use of 40MHz if overlapping channels are present.

Last edited 2 years ago by J1mbo (previous) (diff)

comment:4 Changed 2 years ago by yurtesen

I have access to IEEE Xplore, but you can get it free also:
http://standards.ieee.org/about/get/802/802.11.html
You are right about the standard. I was a bit hasty to decide this was a bug. But OpenWrt does not have Wi-Fi certification anyway, and many wi-fi certified APs fail to conform to it based on the article you mentioned, so why OpenWrt shouldnt...
http://www.smallnetbuilder.com/wireless/wireless-features/31744-bye-bye-40-mhz-mode-in-24-ghz-part-2
(and my tests also). I can only imagine that manufacturers are trying to please their customers.
But thank you for the link to the article. It was very informative.
Thanks!

Last edited 2 years ago by yurtesen (previous) (diff)

comment:5 Changed 2 years ago by jow

  • Resolution set to not_a_bug
  • Status changed from new to closed

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