topic Hi Ordonez,CleanAir:With in Wireless

Diferrence Between RRM and Clean Air

Daniel Ordóñez Flores — Mon, 05 Jul 2021 07:25:05 GMT

Hello Everyone.

I want to say thank you for read my post.

Well I'm having some problems here, because I don't get the correct Idea for RRM & Clear Air. For me they do the same.

Can anyone explain me the differente?

Thank you.

Hi Ordonez,CleanAir:With

Ashish Chandra — Wed, 12 Mar 2014 19:00:32 GMT

Hi Ordonez,

CleanAir:

With Cisco CleanAir technology, if an interference source
is strong enough to completely jam a Wi-Fi channel, the
system will change channels within seconds to avoid the
interference, resuming client activity on another channel
outside of the affected area. The system remembers
intermittent interference from persistent sources such
as a microwave ovens, wireless bridges, or wireless
video cameras. Through tight integration with Cisco radio
resource management technology, the CleanAir solution
indicates the channels where these devices operate so
that system administrators can optimize performance and
minimize future disruption.
Others claim to have integrated spectrum intelligence
but can’t effectively distinguish between Wi-Fi and non-
Wi-Fi interference. Spectrum intelligence products from
other manufacturers typically falsely interpret any network
noise as interference and randomly switch channels,
which jeopardizes network stability and may reduce
overall network performance.

Source: http://www.cisco.com/c/dam/en/us/solutions/collateral/enterprise-networks/cleanair-technology/aag_c22-594304.pdf

RRM:

The RF Group Name is an ASCII string configured per wireless LAN controller (WLC). The grouping algorithm elects the RF Group leader that, in turn, calculates the Transmit Power Control (TPC) and Dynamic Channel Assignment (DCA) for the entire RF Group. The exception is Coverage Hole algorithm (CHA), which is run per WLC. Because RF Grouping is dynamic, and the algorithm runs at 600-second intervals by default, there might be an instance where new neighbors are heard (or existing neighbors are no longer heard). This causes a change in the RF Group that could result in the election of a new Leader (for one or multiple logical RF Groups). At this instance, the Tx Power Threshold of the new group leader is used in the TPC algorithm. If the value of this threshold is inconsistent across multiple controllers that share the same RF Group Name, this can result in discrepancies in resultant Tx power levels when the TPC is run

Source: http://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/71113-rrm-new.html

RRM and CleanAir perform approximatley the same.

Only difference being in CleanAir they have implemented spectrum level intelligence which can differentiate between different wireless interfering devices for ex: microwave oven , cordless phone. With this if youre using NCS you can easily plot and mitigate the source of interfernce with exact device type.

Chandra.Thanks for your

Daniel Ordóñez Flores — Wed, 12 Mar 2014 19:17:36 GMT

Chandra.

Thanks for your answerd, so if I get this right RRM use TPC, Cover Hole Detection and DCA, for mitigate interference issues?

RRM can decide if my AP works on channel 1 and one big interference is jam this channel RRM can say to the AP "Swicth to channel 6" ? I'm right?

The only Difference is with Clean air can I know what device is making this interference?

Correct :)

Ashish Chandra — Wed, 12 Mar 2014 20:10:37 GMT

Correct 🙂

Thank you :)

Daniel Ordóñez Flores — Wed, 12 Mar 2014 21:19:46 GMT

Thank you 🙂

CleanAir has a list of most

Leo Laohoo — Wed, 12 Mar 2014 21:29:38 GMT

CleanAir has a list of most-common interference. It will say, "I detect a Bluetooth device" but can't say, "I am detecting a Panavision microwave oven" or "I detect a DECT handset by RCA". In order the CleanAir to work, DCA and TPC must be enabled.

Ok.I get that, but If my AP's

Daniel Ordóñez Flores — Thu, 13 Mar 2014 00:04:16 GMT

Ok.

I get that, but If my AP's don't have clean air, can I trust on RRM?

I ask this because we have a big problems in a Hotel, very exclusive and another company deployed a wireless network with Unifi AP's form ubiquiti networks.

I was reading about them and they use a class of RRM because they can select automatically their Channels. So I was thinking in cisco, but I'm not sure what kind od AP are the best, and I know the Hotel is surrounded by many antennas and wireless network. So I think in clear air

Can you trust RRM... sure you

Scott Fella — Thu, 13 Mar 2014 01:35:57 GMT

Can you trust RRM... sure you can, but if your AP's are in hallways, then no. DCA is fine, but TPC will be the downfall with AP's in hallways.

Depends on the type of

Leo Laohoo — Thu, 13 Mar 2014 02:40:36 GMT

Depends on the type of interferrence. If you have another wifi device, then yes. RRM can be trusted.

But if we are talking about Bluetooth devices, wireless microphones, DECT phones, then RRM wouldn't even know what the interferrence are.

Sorry Scott, but why Can not

Daniel Ordóñez Flores — Thu, 13 Mar 2014 03:48:17 GMT

Sorry Scott, but why Can not trust? And exist a work around for this issue?

I see, and clean air does?

Daniel Ordóñez Flores — Thu, 13 Mar 2014 03:52:31 GMT

I see, and clean air does?

If all your APs are in the

vlad.mihailov — Thu, 13 Mar 2014 17:11:15 GMT

If all your APs are in the hallways and cover offices to located on the sides then APs can see each other and will lower trasmit power (as they have direct LOS to each other). This may create an issue with the signal strength in the offices themselves. To avoid this issue either survey in such way to hide APs in the offices (perhaps rotating sides of the hallway) or manually configure the transmit power settings. As for trusting the DCA - ... no one answer. I have seen it pick rotate channels too close to each other and not use perfectly available channels.

It also doesn't also switch 2.4GHz frequencies off in dual channel APs when APs are densly installed.

Well most of AP's are in

Daniel Ordóñez Flores — Thu, 13 Mar 2014 17:22:55 GMT

Well most of AP's are in rooms, but the guest complaint because when they come out to hallways the lost conectivity.

Vlad explained it pretty well

Scott Fella — Thu, 13 Mar 2014 17:23:50 GMT

Vlad explained it pretty well. RRM doesn't know what the coverage is in rooms. When APs are LOS or hear each other, the algorithm will lower the TX power. This is the same issue in warehouse in which the AP's are LOS at ceiling level. RRM reduces power to reduce the interference or should we say noise. Hallway designs are a thing of the past per say and not recommended for newer installs when the controller uses an algorithm to calculate power. This goes for other vendors products also. With stand alone AP's, it was okay because you set the power.

So the best way is set the AP

Daniel Ordóñez Flores — Thu, 13 Mar 2014 17:35:19 GMT

So the best way is set the AP in rooms and cover the Hallways with this same AP's?

And If I got this right I never user ar linear desing in hallways or wharehouse if I'm using WLC?

Yes. This is the sole

Leo Laohoo — Thu, 13 Mar 2014 21:14:14 GMT

Yes. This is the sole function of CleanAir.

CleanAir has a small "list" of potential wireless interferrence signatures. Once identifies, CleanAir will evaluate the strength of the interferrence and changes the channel and/or radio power if necessary.

So far, this feature is unique in the industry.

Re: Diferrence Between RRM and Clean Air

jiflorwi — Wed, 13 Dec 2017 20:41:12 GMT

There seems to be confusion regarding the difference between CleanAir and RRM. They're two completely separate features. For certain use cases they can collaborate when it makes sense.

CleanAir is a silicon level spectrum analyzer embedded into the radio chip set. It's sole purpose in life is to detect, classify and measure sources of NON Wi-Fi radio signals. To the Wi-Fi model - these simply appear as noise.

With or without CleanAir - RRM is reactive to noise. The DCA channel algorithm measures Noise on a channel along with signal (which is our AP's transmissions) and interference (other AP's or Rogue's transmissions). The Wi-Fi chipsets defines anything that can not be demodulated as Wi-Fi to be "Noise".

CleanAir is capable of identifying non-Wi-Fi sources of noise. It does this by first pattern matching the radio waves at the physical layer, and then analyzing these using DSP modems to interrogate the sample. It is extremely accurate and can easily identify multiple instances from even the same type of device (Bluetooth for instance - CleanAir can demodulate the link address - and allows us to keep track individually of multiple bluetooth sessions).

CleanAir can identify, evaluate severity (how much airtime am I losing because of this non-Wi-Fi device), and locate it on CMX and NCS maps. It strictly investigates and analyzes NON-WI-FI.

RRM's DCA runs by default every 10 minutes. With DCA alone - we would see the "NOISE" and if there is a better channel for that AP, change channels in reaction to it.

With CleanAir, identifying the Noise Source happens at the AP,

One example where CleanAir helps RRM is - ED-RRM . Certain kinds of interference are extremely destructive and interrupt a Wi-Fi conversation immediately. A video camera for instance, transmits at 100% duty cycle - it is always on. Because Wi-Fi uses listen before talk to access the channel - this means every time the AP or the clients attempt to access the channel for transmit - they will hear that video camera and defer (not transmit because the link is in use). This will stop a complete cell and all of it's clients from talking - ever. DCA will of course change the channel - however this could take 10 minutes. CleanAir ED-RRM (Energy Detect RRM) allows the AP that positively identifies interference sources of this type to immediately change it's channel - and tell RRM after. This happens in as little as 30 seconds.

Another example of how CleanAir helps RRM do a better job is in mitigating persistent non Wi-Fi interference. Lets use a Microwave Oven as an example. In an office - the Microwave will run pretty much constant through the lunch hour - and then again at around 3 PM for the popcorn crowd. During the time the microwave operates - any AP near it will have interference (unusable) while it is in operation anywhere between channel 6 and 11 in 2.4 GHz. RRM will move the AP's, however once the Microwave has stopped - it is quite likely that the best channel was in the path of that Microwave oven - and the whole thing will repeat the next day. Persistent Device Mitigation will allow the AP to remember that the microwave is there, this is communicated to RRM and a Bias is put against the affected channels - for that AP alone. DCA will calculate a channel plan that avoids the interference - only in the areas where it impacts your AP's. The interference is "remembered" by the AP for 7 days. If it is never detected again - it clears, but it also refreshes for another 7 days each time it is detected.

https://www.cisco.com/c/en/us/solutions/collateral/enterprise-networks/cleanair-technology/white_paper_c11-599260.html?dtid=osscdc000283

Re: Diferrence Between RRM and Clean Air

Martin H. — Fri, 15 Dec 2017 07:53:03 GMT

Thanks Jim for clarification.

Re: Diferrence Between RRM and Clean Air

tonisaprano — Wed, 21 Mar 2018 10:42:00 GMT

thanks, Jiflorwi. When RRM/Event RRM is starting to work does it affect on client connections at that moment?. I mean it causes the client disruption?