Access Point Channel Deployment

[jason crockett]

We are starting to greatly increase our access point density throughout our floors and I am wondering if we are using the correct channel assignments. We are using LAP 1140's and 3500's. We have some locations that have have anywhere from 4 to 9 floors in one location. These are consecutive floors that have 8 to 11 APs per floor. There are also other businesses in these buildings that use wireless as well. We use 802.11a/n and 802.11b/g/n. Right now the channels are set to the default, (36, 40, 44, 48, 52, 56, 60, 64, 149, 153, 157, 161 for 802.11a) and (1, 6, 11 for 802.11b/g/n). I was wondering that since we are increasing our density whether we should enable other 802.11b/g/n channels outside of 1,6,11. I know the other channels can overlap but with correct placement I am wondering if it would improve our wireless coverage since we wouldn't have 8 to 11 APs fighting for only 3 channels. Has anyone experimented with enabling other 802.11b/g/n channels? If yes, please share your experience. I have attached one of our heat maps for one of the floors I described above. Also, send me a link to any articles you think may be helpful. Thank you!

[Scott Fella]

I would have to say no. On the 2.4ghz you should keep using channel 1, 6, and 11.

Thanks,

Scott Fella

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[jason crockett]

Scott, what are your thoughts on sticking with channels 1,6,11 but manually assigning them rather than letting the controller choose the channel?

[Scott Fella]

That is okay, as long as you know that the spectrum is okay when using a particular channel. If you are using 3500's or 3600's using CleanAir, then you need to leave RRM on an enable EDRRM. So it depends on your implementation.

Thanks,

Scott Fella

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[Leo Laohoo]

Scott, what are your thoughts on sticking with channels 1,6,11 but manually assigning them rather than letting the controller choose the channel?

Then why bother putting a WLC?  One of the features with the WLC is the ability to regularly change the channel when the noise of the nearby wifi neighbor gets in the way.  So if you disable DCA then how often will you review your channel assignment?

[Scott Fella]

Haha... It's just one option. These days RRM is better, but for those with older equipment and older code, it might not be. It was the domino affect that put a bad taste to RRM. Again it varies on the install, but we all did channel assignments back in the days:) its like having the WLC adjusting power... Some times you just have to set things if the norm doesn't work for you.

Thanks,

Scott Fella

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[jason crockett]

Believe me, one of the selling points that made us go with the controller was RRM. But I have noticed when having a very high AP density that channels and power levels don't adjust accordingly. So consecutive APs can be on the same channel or at high power levels. We have a 5508 running 7.0.220.0 code so we are running one of the latest codes.

[Leo Laohoo]

We have a 5508 running 7.0.220.0 code so we are running one of the latest codes.

Hi Jason,

Latest code for the 7.0.X is the 7.0.230.0.

If you want the latest-and-the-greatest then it's the 7.2.X.  Because you have the 5508, I'd recommend you go to the 7.2.X as it has more features than the 7.0.230.0.

One more thing, the new 7.2.X has a new TPC version, however Cisco is recommending people stay with the current version as the new version is still in a "beta" state.  Future releases will allow the TPC (and maybe the DCA) to be fully operational.

[jason crockett]

Thanks for the info. I may try upgrading to 7.0.230. I am going to wait on the 7.2.X code since it was recently released and may have some bugs.

[jason crockett]

I do not see any open caveats in the 7.2.103.0 version that would affect me. Has anyone tried this IOS version yet? If yes, can you share your successes or failures?

[Scott Fella]

Jason,

The thing is, its okay if the ap's at times have the same channel as one of its neighbors.  You really cant prevent that especially if you have aps above and below.  I would just leave RRM decide the channels unless your users are complaining.  I have huge installs with that code and also 7.0.230.0 and of couse I see AP's next to each other on the same channel.  I don't think 7.2.103.0 will help, but you can try.  I ran 7.2.103.0 but had some issues with anchoring and managing anchored WLC's, that i reverted back to 7.0.230.0.

[George Stefanick]

One thing I have not heard mentioned is that your rf design really needs to be consider for rrm will run optimally.

If you have sparse deployment rrm may power everything very high. Or if you have aps to close they could power them very low leaving gaps.

Once it's up and running you would hope to see they balance between power levels at 2 - 4.

Just my 2 penny's worth ..

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