Thoughts on Wide Channels

[sfx2000]

The last time I used 40 MHz channel width on the 2.4 GHz band, the customer's Internet would cut off whenever his cordless phone rang (this was before the DECT 6.0 days).

I've been DECT for a long time - and these days, the hardline is seldom used - and many have done away with it...

Most devices will downgrade to 20 MHz whenever there's any interference. Between microwave ovens, Bluetooth and neighbours, this will most likely happen a lot.

Bluetooth is what drove Apple with their FAT channel intolerant modes - with 11n Airports still set that bit in the Beacon frame, and all of their clients are 20MHz only for 2.4GHz...

Microwave Ovens - still a big noise source/jammer - it's broadband noise, and short term, and mostly won't trigger an AP with Wide Channels to go to 20MHz, as even there, the noise source would impact everything, including bluetooth.

Neighbours - less so lately, as I've seen both the off-the-shelf mesh/mulitple point wireless systems, along with Broadband Provider Prem gears, they used to follow the 1/6/11 until the last 18 months or so, where I find them now starting to pop up in the 1+4 scheme, so a lot of stuff on 1+5, 11-7, and 5+9 wide... the 5+9 or 9-5 configs are probably the most troublesome for those looking to be "nice" as it pushes many to 1 or 11...

Anyways - with the newer chipsets, better radios, and keep in mind that 802.11n was always designed to take advantage of wide channels when and where available, it's worth a try in the SOHO environment... worst case is that one will still have 20MHz to work with.

For large scale enterprise/hospitality deployments, 20MHz absolutely makes sense, where one does have some central management in place....

 

[sfx2000]

The last time that 2.4 GHz Wide Channels was looked at on the main site was in 2012...

https://www.smallnetbuilder.com/wir...es/31743-bye-bye-40-mhz-mode-in-24-ghz-part-1
https://www.smallnetbuilder.com/wir...es/31744-bye-bye-40-mhz-mode-in-24-ghz-part-2

And that was a long time ago, with 11n silicon and AP and Client drivers that were largely based on legacy 11 b/g...

This is an interesting article from 2012 - just at the cusp of 802.11ac

https://www.smallnetbuilder.com/wir...94-why-80211ac-will-kill-the-5-ghz-wi-fi-band

And we know where we are at the present - again, better chipsets, better firmware - otherwise all these Mesh things would be spectacularly challenged, and they're not...

Going to very wide channels in 11ac - e.g. the 160 and 80+80

https://www.smallnetbuilder.com/wir...es/33210-160-mhz-wi-fi-channels-friend-or-foe
https://www.smallnetbuilder.com/wireless/wireless-features/33212-160-mhz-wi-fi-channels-revisited

I'm totally ok with this - seriously I am - if you've got the gear to do it, why not? It's the client that really drives the bus there... but if the AP is capable, it should make it available.

 

[RMerlin]

If Tim were to revisit wide channel support, my recommendation would be to wait for 802.11AX clients to appear, and then to do some thorough testing on the 2.4 GHz band to see how things have evolved since the 802.11n days. 40 MHz channel support would be just one item to check then, in addition to the various 802.11ax enhancements (and the new generation of wifi clients, which might also have improved).

 

[MichaelCG]

Oh how I wish SmartThings let you pick your own ZigBee channels. I am stuck with Channel 19 which falls right in the middle of the 2.4GHz band, so WiFi Channel6 is off limits in my house. As well as Sonos is sitting on Channel 11.

 

[sfx2000]

If Tim were to revisit wide channel support, my recommendation would be to wait for 802.11AX clients to appear, and then to do some thorough testing on the 2.4 GHz band to see how things have evolved since the 802.11n days. 40 MHz channel support would be just one item to check then, in addition to the various 802.11ax enhancements (and the new generation of wifi clients, which might also have improved).

That would be interesting - and include legacy b/g and older N (WRT160 era), along with the AC1900 class representative examples (AC-68U or R7000)

 

[Leo Fender]

Are wide channels in recent designs useful for bi-directional transfers, or still limited by shared spectrum?

 

[sfx2000]

Are wide channels in recent designs useful for bi-directional transfers, or still limited by shared spectrum?

Still shared spectrum, and access for all 802.11 a/b/g/n/ac follow the same rules...

11ax with it's scheduled MAC may have some improvements there.

 

[coxhaus]

If you want wide bandwidth use 5 GHz. I switched many years ago. I would never go back to 2.4 GHz. I am real happy using only 5 GHz. If you need better 5 GHz coverage use multiple wireless units. I now use 3 Cisco WAP571 units. They work well.

 

[sfx2000]

If you want wide bandwidth use 5 GHz. I switched many years ago. I would never go back to 2.4 GHz. I am real happy using only 5 GHz. If you need better 5 GHz coverage use multiple wireless units. I now use 3 Cisco WAP571 units. They work well.

2.4GHz is still useful and with many IOT oriented projects - it's needed... still amount of BW there..