Unable 40MHz bandwidth in the 2.4GHz band?

Jan Ceuleers jan.ceuleers at gmail.com
Wed Apr 17 05:51:31 PDT 2019

On 16/04/2019 21:45, Nicolas Boullis wrote:
> Any hint how I can understand why 40MHz is not enabled?

As Jouni said this is likely because the standard requires APs to
minimise interference with other spectrum users by staying at 20MHz
bandwidth unless the other channel is unused.

Let me add that hostapd is the only AP implementation I've seen that
actually complies with the coexistence rules. All commercial APs I have
seen (and this includes openwrt etc on fullmac devices) flout the rules
(and trample on the neighbours' signals) for marketing reasons.

There have been attempts over the years to get Jouni to accept patches
that also make it ignore the coexistence rules and he has rightly
rejected them. This is not merely a matter of religiously adhering to
the standard, but also of not adding to the overcrowding in the 2.4GHz band.

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