Allowing station to over-ride default VHT-oper element?
I'm trying to figure out how to make a VHT station with hardware capable of 80Mhz width instead force itself to advertise/use just 40Mhz width, but still support VHT.
Similar to how the VHT-capabilities overrides works, but for VHT-operation.
First, is this even a valid thing to do, or does VHT imply that stations are always available to do 80Mhz?
And second, if it is a valid thing to do, any hints on a proper way to go about this. I'm getting a bit tangled in the code trying to figure out where to apply any overloads properly.
Possibly in ieee80211_determine_chantype?
Thanks,
Ben
Signature · 2 lines
Ben Greear <[email protected]> Candela Technologies Inc http://www.candelatech.com
Quoted 2 lines · Ben Greear
First, is this even a valid thing to do, or does VHT imply that stations are always available to do 80Mhz?
According to the spec, a VHT STA must support 80 MHz:
802.11ac-2013, 22.1.1:
A VHT STA shall support the following features:
[...]
- 20 MHz, 40 MHz, and 80 MHz channel widths
Consequently, there's no bit indicating whether or not 80 MHz bandwidth is supported (like there is, for VHT, indicating 40 MHz is supported or not.)
Also it is invalid to advertise a VHT capabilities IE and an HT capabilities IE without 40 MHz.
johannes
Quoted 13 lines · Johannes Berg
Quoted 2 lines · Ben Greear
First, is this even a valid thing to do, or does VHT imply that stations are always available to do 80Mhz?
According to the spec, a VHT STA must support 80 MHz:
802.11ac-2013, 22.1.1:
A VHT STA shall support the following features:
[...]
- 20 MHz, 40 MHz, and 80 MHz channel widths
Quoted 6 lines
Consequently, there's no bit indicating whether or not 80 MHz bandwidth is supported (like there is, for VHT, indicating 40 MHz is supported or not.)
Also it is invalid to advertise a VHT capabilities IE and an HT capabilities IE without 40 MHz.
Ok, thanks for that..one less piece of work for me to do :)
Quoted 1 line
From what I can tell, it *IS* ok to have an AP do VHT on 40Mhz though?
Thanks,
Ben
Signature · 2 lines
Ben Greear <[email protected]> Candela Technologies Inc http://www.candelatech.com
Quoted 3 lines · Ben Greear
Ok, thanks for that..one less piece of work for me to do :)
From what I can tell, it *IS* ok to have an AP do VHT on 40Mhz though?
It may even be compelled to do so by the spec, since there could be overlapping networks (see 10.39.2.)
johannes