How many 80Mhz wide channels?

[srosenthal]

I am getting ready to install some 3700 series AP's and then also configure the WLAN controller to support 802.11ac.  I was reading on the net that there are basically 5 80Mhz channels you can use however when I look over Cisco documentation I do not see any reference to this and only see a DCA listing that would allow only 3 80Mhz wide channels.  Here is the document I mentioned. - http://www.cisco.com/c/en/us/td/docs/wireless/technology/5760_deploy/CT5760_Controller_Deployment_Guide/802_11ac_support_on_WLC5760_and_Catalyst_3850.html

Here are the channel groupings for 5 channels that I want to setup:

36-48
52-64
100-112
132-149
153-165

Am I missing something or will this work? 

Seth

[Stephen Rodriguez]

Per the AP data sheet, it does support up to 5 80MHz wide channels.

http://www.cisco.com/c/en/us/products/collateral/wireless/3700-series-access-point/data_sheet_c78-729421.html

On the link you shared, they do not have UNII-2 band enabled(look at the list of supported DCA channels it jumps from 64 to 149), probably because of DFS.  If you were to enable UNII-2 you should be able to get the 5 channels.

That being said, personally I'd stay away from the DFS channels just to be safe.

HTH,

Steve

[srosenthal]

Thank you for the information.  I see what your saying in the data sheet, although it does not mention which 4 channels.  Do you happen to know?

Seth

[Stephen Rodriguez]

I'd tend to think the three channels would be

36-48

52-64

and probably

149-153

HTH,

Steve

[srosenthal]

52-64 are also DFS channels so I were to stay away from DFS then that would only leave 2 channels.

Seth

[George Stefanick]

Seth,

I would consider doing the 40 Mhz channel and ease into 802.11ac. Clients are still very new and you will and could see issues at 80 MHz. 

[mohanak]

80 MHz wide channels allow for five (5) non-overlapping channels in the U.S. and five (5) in the UK/EU (channels 149 and higher require light licensing for outdoor use only) when DFS is used, but only two (2) channels in the U.S. and one (1) in UK/EU without DFS.

[srosenthal]

I understand the US allows for 5 channels, however the data sheet for the 3700 AP states it only  supports 4 80Mhz channels.  So that leaves me to wonder which 4 channels?  What if I configure my WLC for 5 channels, will the 3700 just resolve to using the same 4 channels or will it rotate between all 5?

Seth

[Moin Ilyas]

Best Practices – Understanding Channels, Clients and so on

Currently in the US, there are 22 (20 MHz) channels, 9 (40 MHz) channels, and 4 (80 MHz) channels. 802.11ac (Wave-2) supports 160 MHz channels but there is only 1 channel available today; this is likely going to get better because the Federal Communications Commission and other regulatory bodies realize the need for more unlicensed spectrum and are actively working to free up more spectrum.

Let us take a look at the frequencies available and how the channel bonding would work.

Right now in the US, there are only four 80 MHz channels but this will likely improve.

Figure 84 Current Channel Allocation Plan - US Theater

Hope that helps.

[Abha Jha]

The answer will depend on the regulatory domain
of the AP. In the US, there are 5 contiguous
80 MHz channels. Those 80 MHz channels can be combined to create 160 MHz channels.
There are only 2 80 MHz channels that do not require DFS