Receving from 2.4 and sending to 5 ghz

[jim_konng]

Hi all,

Need to understand one thing. As we know that before 802.11ac MU-MIMO, it was single user communication. I just wanted to know if below scenario is applicable in real life (no specific to ruckus)

1. 1 client associated to AP on 2.4 Ghz, another client associated to AP on 5 Ghz
2. On radio medium, only 1 device can sent at a time
3. if client 1 (2.4 ghz) is sending data, will client 2 (5 ghz) will recieve it simultaneously ?

I think in point 3, the communication should be bidirectional isnt it without any hold up since both clients are operating on different frequencies ?

[seanmuir]

You are correct.

All you need to know is that WiFi is 50% duty cycle and the MAC layer can either be based on throughput fairness (equal amount of frames) or airtime fairness (equal amount of airtime) and this is radio dependant.

[jim_konng]

so which one does Ruckus support ? throughput fairness ? or airtime fairness ?

[seanmuir]

Airtime Fairness:

https://support.ruckuswireless.com/answers/000002008

[john_d]

A simultaneous dual-band AP can be thought of as two separate AP's operating independently: One serving 2.4GHz and one serving 5GHz. So yes, it would be possible (and has nothing to do with 802.11ac MU-MIMO) for separate clients to be either sending or receiving at the same time on 2.4GHz and 5GHz. It's merely a "convenience" that the most popular AP configuration is shipping a two-in-one dual band.


On the consumer market, you also see weirder configurations, like AP's that have two 5GHz radios and one 2.4GHz one.

But this kind of scenario isn't MU-MIMO, it's just you are saturating more of your channel spectrum with additional AP's.