5Ghz VoWLAN deployment, channel bonding issue or not?

[Joeri De Winter]

HI all,

Question regarding a 5GHz VoWLAN deployment in the 5GHz band.

Let's say you have an multiple floor building in a city environment, and you need to deploy VoWLAN on one floor in that building, during the site survey you noticed that the 2.4GHz band is to noisy and that all channels of the 5GHz band are occupied by the neighboring companies on the upper and lower floors, even more all 5GHz channels are configured for channel bonding, the utilization % is low on all bonded channels but the site survey is done on a holiday.

• Could this scenario cause problems when you want to deploy VoWLAN (20MHz channels) in the 5GHz band?
• Any tips or tricks for this scenario?

Regards

Joeri De Winter

[Leo Laohoo]

20 Mhz or 40 Mhz channel bonding with 802.11a/n doesn't make any difference as there's still alot of channels to play with.

[Joeri De Winter]

Hey Leo,

Not much room to play here!

Cheers

[Leo Laohoo]

Geez.  That's one crowded spectrum.

Is EWA your network?

[Joeri De Winter]

Nope,

It's a remote customers network in Sweden, they have one floor in a 7 floor building, and thay want to deploy 100 x Cisco 7925g phones.

We always push the 7925g phones to the 5GHz, but in this case I want to make sure....

[Leo Laohoo]

It's too crowded to use channel bond, in my opinion.  What AP model are you using?

I think if you have an AP which supports CleanAir, you just might be able to run channel bond for voice.  You may need to put extra AP and bring down the data rates to, say, only allow 18 Mbps and above only.

George, Scott, Steve, Surendra, opinion?

[Joeri De Winter]

We have foreseen the 2602i series for the deployment, but want to deploy 20Mhz channels in the 5GHz for Voice, I did the onsite survey for additional capacity (some of the 2.4GHz radios will be disabled) to counter CCI.

[Leo Laohoo]

2602 and 3602 are two models I highly recommend.

Don't disable 2.4 Ghz because there are some clients who don't have 802.11a radios.  Like I've mentioned before, disable low speed data rates (both radios) from 1 Mbps up to 12 Mbps.  Make the next one up, in your case 18 Mbps, "Mandatory" and the rest are Supported.

Enable channel bonding and check the airwaves.  If you get excessive channel interferrence then break it apart. 

[Joeri De Winter]

Hey Leo,

Im not gone disable the 2.4GHz, only a couple of them that are located in meeting rooms (additional capacity).

My question is:

in this scenario, what would be the best design and why.

VoWLAN design with 20Mhz channels or 40Mhz channels?

many thx

[Saurav Lodh]

The 5 GHz band now has 20 channels. These are  non-overlapping channels, which means that they can all be co-located. Please follow the Voice over WLAN design recommendations from below

http://www.cisco.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch9_Voic.html#wp1073934