cancel
Showing results for 
Search instead for 
Did you mean: 

ZF710: MU-MIMO and BeamFlex

jason_hinterste
New Contributor II
Is there a white paper or other reference explaining how MU-MIMO works in conjunction with BeamFlex?
8 REPLIES 8

eizens_putnins
Valued Contributor II
http://www.theruckusroom.net/2014/05/beamforming-bull.html
link to document about beamforming I mentioned.

eizens_putnins
Valued Contributor II
Sensitivity is one thing, backoff threshold is something completely different. More sensitive AP means that it actually hears weak signals and can make competent decision backoff or not. If sensitivity is not so good, AP just can't hear this signals and takes no actions. It also means that level of own noise is reduced, so for normal and low signal levels SNR is a bit improved.
I don't know how exactly backoff policy is optimized, but it is obviously that it is done in Ruckus (and probably all other enterprise vendors do it too).
I have seen multiple installations near busy wi-fi networks (mostly hotels), where level from neighbor hotel network was about -75 - 80 db, no other interference, and SOHO equipment just didn't work (Linksys, Ubiquity, Mikrotik) even when client is nearby (5 m).
We observed 100% signal level, packet loss  about 20% and ping times 50 - 1000 ms. So nothing worked. I suppose reason is that AP hears hotel network traffic all the time, and as a result has almost no airtime, because hotel network is heavily loaded and ignores AP frames (or doesn't hear them at all).
Just replacing AP by Ruckus resolved this problems.

john_d
Valued Contributor II
I've observed the same thing as Eizens — even though my Ruckus AP's are capable of seeing other AP's much better than my consumer equipment before it, it seems to be able to make just as good if not better decisions about whether or not to wait or talk, as well as being able to hear mobile device transmissions from a further range.

Of course, only Ruckus knows what their magic sauce is here (whether or not the periodic noise floor calibrations set the threshold for wait or transmit on top of noise, or if on the decode side ML is used to decode the smartphone transmission superimposed on other weak noise), but it seems like sensitivity works in its favor, not against it.

The R700 being a couple dB more sensitive on 5GHz than the R600 yields similar range benefits in my experience.

I think you might be mixing a few things here. In my experience Ruckus solves many problems also, however an AP receives ALL RF signals present in the air and there's A LOT more to it than a high sensitivity threshold. That's all I'm saying.