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First of all I'm sorry for the long winded topic. I have so many questions about deploying 802.11n and can't seem to find anyone that really has experience doing it.

Does anyone have experience deploying 802.11n in the hospitality industry? I'm mainly concerned with the guestroom areas. These areas obviously have multiple walls and other obstructions to deal with (lots of multipath). I have a few questions on the best way to deploy "n" in an environment where I'm more interested in the RF benefits I will get with "n" such as MIMO and beam-forming.

I will be using the following gear: 1 X HP MSM7XX controller.
About 15 X HP MSM422 AP. This AP is a dual radio but only 1 is capable of 802.11n.
I've included this link which covers how to deploy an MSM422 (formerly Colubris MAP-625)

http://cdn.procurve.com/training/Manuals/r523/80211n-Best-Practices-1.1.pdf


My thought is to deploy 802.11n in 2.4GHz using 20 MHz channels allowing backward compatibility to b/g. This way all of my legacy b/g clients will receive the benefits of using 802.11n. Sure my "n" clients will see lower "n" speeds but I'm more concerned with improving my legacy clients performance. The other radio I'll set to 802.11a. Keep in mind these WLANs are only used for internet access, which is usually several T-1s.
One other option would be to use 802.11n 5GHz using auto 20/40GHz channels. The other radios would be set to b/g. This option would be good for "n' clients but what about legacy b/g? My legacy clients wouldn't receive the benefits I mentioned earlier. A big reason I'm deploying "n" is to improve the performance for my legacy b/g's.

I guess my main question here is this; What is the best way to deploy 802.11n in an environment where we have no control over types of clients that use the network while also maintaining the same signal penetration and distance of 2.4GHz? In other words I don't want to have to use 20 "n" APs to cover what 10 b/g would have covered.

If we deploy 802.11n in 5GHz what types of signal propagation can we expect? The same as 802.11a?

My recommendation would be as follows:

2.4GHz is the Legacy frequency
802.11b/g reside here
If you have an 802.11n 2.4GHz the clients will still connect, but the AP will be able to 'hear' better.
20MHz channels ONLY
SSID - XXXXX

5GHz is the 802.11n Greenfield frequency
NO 802.11a
40MHz channels ONLY
No 'mixed mode' - 802.11n ONLY
SSID - XXXXX-FAST or XXXXX-n

Everyone with a non-802.11n device will connect to the XXXXX network using 802.11b/g

Anyone with an 802.11n card can/should/will connect to the XXXXX-FAST or XXXXX-n network and have all the benefits of 802.11n, MIMO, etc.

Anyone who has an 802.11a ONLY card will be SOL... but how many people have an 802.11a ONLY card?

I agree with Keith, and I think you have to boil your deployment down to specific goals.

If you want to support devices in 5 GHz...
If you only have one 802.11n-capable radio, configure it for 5 GHz. Contrary to their AP spec sheets, HP doesn't support beamforming, so you won't get any better Tx performance or RF propagation from your 802.11n radio. Like Keith said, you'll see better Rx (hearing) performance by the MIMO radio, so this might help AP reception performance at range, which would be more beneficial in 5 GHz. APs already have better radios than most clients, so the range benefit with legacy clients is nominal. However, if you are only concerned with 802.11n clients in 5 GHz, you get MRC on the client as well, so performance at range will be improved.

Thanks for the advice.

So it sounds like the best option would be to have one radio using 802.11n 5GHz 40 MHz channels. The other radio set to 802.11b/g.
I'm still a bit confused...This setup will offer "n" support in 5GHz( which will be great) but this setup will offer no benefit to my legacy b/g clients. Actually one benefit may be clients with an "n" 5GHz capable card "might" associate to the "n" radio, thus less clients on b/g. So lets say a a/g/n client fires up and attempts to associate to the network. I would think the client would choose the strongest signal. Whether or not this is "n" or b/g probably will be determined on how the WLAN was designed.

Do either of you have any experience site surveying for 802.11n 5GHz? Or are you aware of any documentation? Fortunately I have the latest Airmagnet Site Survey Pro which supports 802.11n. This should assist me in this process.

Yes, I have lots of experience in doing 802.11n surveys - specifically with AirMagnet Survey Pro.

The b/g clients will get a slight improvement when connecting to an AP with 802.11n chipsets, even if many of the n-specific features aren't available to them. The AP is still a better 'listener'.

If you offer an SSID to 'help' folks move up to 5GHz all the better, each one that moves gets a much better experience, while leaving space down in 2.4Ghz for others to use.

Too many items to talk about in doing an 802.11n survey for a simple blog-post.

If there is interest, perhaps I can condense part of my 802.11n course, and Site Survey course into a white paper to post here.

Signal propagation for the 5GHz will be at least as good as 802.11a - and sometimes quite a bit better.

This setup will offer "n" support in 5GHz( which will be great) but this setup will offer no benefit to my legacy b/g clients.

I mentioned that you should find your primary goals for an 802.11n upgrade. What benefit are you looking for from 802.11n? If the upgrade is for faster speeds, you may rethink your WAN pipe or rethink the upgrade. I'm not sure what your "upgrade to 802.11n" goals are, so it is hard to say how to deploy your network. Keith definitely shared the best practices approach to dual-band deployment when only one radio is .11n capable. Keith also has far more experience in site surveying than I do.

Supporting more devices in 5 GHz will help create a cleaner 2.4 GHz deployment, but if your 2.4 GHz utilization isn't high, this won't improve user experience. If 2.4 is crowded, as with most networks, band-steering mechanisms may be helpful (don't think HP supports this yet). Keith also addressed this in his original post recommending that you use SSID naming conventions that steer users with a/n-capable devices to 5 GHz. You can't rely on client device algorithms to choose 5 GHz, so you have to do this with your infrastructure.

I would be grateful for any info you can share concerning "n" surveys. I've actually seen the new 802.11n video from CWNP. Is this what you are referring to?

As far as my reason for moving to 802.11n:

1. We have clients that want it and are willing to pay for it and want the latest and greatest.
2. I want the benefits that "n" offers not only for "n" clients but legacy clients.
3. Many of our clients have large conference spaces. Many users concentrated together. What I've read and videos I've seen all say "n" offers increased capacity over a/b/g. Of course there are many factors to consider when deploying "n". I totally agree about the WAN link being the bottleneck.


What 802.11n vendor do you guys recommend and why? I've used Colubris now HP for years and I like them. I feel though they are behind when it comes to 802.11n. They don't even have dual-band 802.11n AP yet when every other major player does. I've looked at all the top vendors; Aruba, Cisco, Ruckus, Xirrus, Meru.

Keith, there is definitely interest in such a whitepaper. Please write. :)

11n in a hotel, I hope you are doing that for coverage and levy the use of multipath because I doubt many hotels have an internet connection large enough to handle a whole hotel will 11n clients. And leaving the ability for wireless clients to talk to each other, not a good idea.

If you are using a MSM-7XX controller, make sure you have access control on for each of the SSID's and you might want to limit the throughput per client.

~K