Diferrence Between RRM and Clean Air

[Daniel Ordóñez Flores]

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.

[Ashish Chandra · Accepted solution]

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.

[Daniel Ordóñez Flores]

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?

[Ashish Chandra]

Correct :)

[Daniel Ordóñez Flores]

Thank you :)

[Leo Laohoo]

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.

[Daniel Ordóñez Flores]

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

[Scott Fella]

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.

[Daniel Ordóñez Flores]

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

[vlad.mihailov]

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.

[Daniel Ordóñez Flores]

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

[Scott Fella]

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.

[Daniel Ordóñez Flores]

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?

[Leo Laohoo]

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.

[Daniel Ordóñez Flores]

I see, and clean air does?