Voice Wireless Deployment help - High Utilization w/ no users

[netwrkgod]

“We” have a highly dense AP deployment going on right now in our new HQ building to support wireless voice services.

Unfortunately, the AP's were hung only about 35 ft. from each other. There are about 20 AP's per floor in a three floor building. All three floors have one side without a wall. What I am seeing is that all of the AP's power down to level 8 (the lowest), and each of the AP's has around 30 Rx neighbors. If I leave all of the AP's turned on, the utilization per AP is above about 60% - and up to 100% without any clients associated to it. On the middle floor, I've tried turning off every other AP to see what effect that would have, and noticed the utilization dropped significantly (each AP below 50% utilized), but the power levels never increased on the AP's (I'm assuming because of the gazillion neighbors they see). So, I tried to manually increase the power on every other AP to power level 6. Now, of course, the utilization is really high again.

Is this typical for a voice deployment?

Should the AP's be more like 50-60 feet apart?

Any suggestions? (don't put AP's on the 2nd floor - just 1st and 3rd)?

Please see the attachment.

Thanks!!

[wififofum]

BTW, not to confuse HCCA with HCA, but I never worked for the latter. A cohort of mine knows them well, and I've spoken to one of their folks as a reference for AirWave.

[john.preves]

Very Zen indeed...hahaha! That was good.

Ummm... I attempted to read your document and it might take about a month to absorb and re-read and Google etc...but I'm thinking the gist of it is the time interval is pre-determined either way (HCCA or EDCA)

Meru has described their time division multiplexing as almost like token ring...nobody talks until your finished.

I might want to look into that further since they were probably over simplifying.

I haven't heard anything about the medical equipment people and BSSID's...I will ask about this...thanks. So far we have voice and data no RFID yet or medical pumps, etc. but that's all in the pipe.

I can however, use VNC which is like a server that hosts huge files like a movie and then use a wireless laptop or ten and connect to the server and view the movie across the wireless, while roaming even. I'm not sure how that works or if VNC does some kind of compression, but it is fairly impressive none the less.

[john.preves]

Actually we are going to keep the Cisco for things like remote sites and guest networking. I would prefer a single platform myself, but that fight has been lost and I resign myself to learning both platforms and remaining quite confused on both.

This reason and God punishing me for an incorrigible childhood that lasted well into my late 20's is why I have no hair.

I just hope the fallout from having Cisco and Meru AP's scattered around in the same room is going to be as agreeable to them when it's finished as it is to them now. We shall see.

[wififofum]

John,

You concerned at all about extended NAV timer conflicts between Cisco and Meru APs and clients in close proximity? Does Meru offer a non-Meru compatibility mode? Based on Dave Molta's coverage in Network Computing, it sounds as if Meru's alleged 802.11 tweaks might not make them a good neighbor.

[john.preves]

I am very concerned. This is the argument I lost. I brought up that very article during my dissertation. The powers that be have decided that as long as the Cisco that gets whacked is the guest network, then so what?

If nothing else, I get to have a 'production-lab' and see what happens. I will keep y'all posted.

[wififofum]

John,

I'm jealous -- you get to have some valuable vendor interoperability experience between deployment paradigms. I'm curious, who is pushing Meru as an alternative? The Medical Device vendors? Please keep us posted on your results.

Thanks,

--Bruce

[john.preves]

The hospital and all the boss people above me are pushing the Meru. Actually, it has been pushed already. I have almost one hospital completely Meru now. I have finished surveying one other hospital, currently awaiting deployment, one building of a third (also awaiting deployment), half of one other hospital, and two more in the pipe. Add the guest networking component, another hospital that is on the fence, a whole bunch of doc-in-the-boxes that will most likely remain on Cisco and the occasional break-fix like today and it's a lot to get done. Plus, I'm learning things like switching, trunking and routing from the regular network geniuses. I also get to teach one minion person wireless principles and technique while he helps me put all this together. Truly a righteous gig. I am blessed. (even though its cold eight months out of the year).

Just to clarify - we are still primarily concerned with voice and data. Guest networking is third and somebody is probably talking to the RFID/ medical device people, but I have yet to see a piece of gear for that. I'm sure that is going to happen faster than I can get to it.

Which is why I'm pro-actively doing surveys for facilities that haven't spent money yet.

We never seem to roll out one whole hospital at once. Coverage gets chopped up depending on who's department is paying. I want to have the whole thing drawn out so when they pick and choose who gets what, it will all be kosher in the end.

I hope to have some kind of guest networking up and in test mode this week. It will go in a lobby area where it should get quite a workout with two AP's.

Results will be posted forthwith and breaking developments as they occur.

Peace-

[wififofum]

Thanks John,

You may want to include location in your current surveys, but with the proviso that some of the APs deployed will need to be receive-only (peripheral APs). Its probably better to consider this an overlay on an existing data deployment. I would make sure you be diverse in the placement of APs going forward as preliminary preparation. Avoid horiztontal and vertical stacking, offer at least some measure of variation in RSSI for location piloting.

Interesting impetus for Meru. It doesn't sound like you have to deal with pumps yet. We've found these vendors to be unwilling to adopt any non-IEEE spec (or they're hiding behind this so as to not have to re-engineer for CCX compatibility). Hence their own SSID to avoid bcast/mcasts from others (God knows a pump CPU is probably half of what's in my PDA). Single channel will certainly facilitate a client that doesn't have any roaming logic.

I assume you can have multiple single-channel zones via subordinate controllers? Devin Akin of CWNP has been a spokesperson for Meru of late, and I believe/assume he uses the term "stacking" to convey this capability?

We have the same funding model, and it makes a lot of sense for you to do the building in advance to maintain continuity in the deployments. Just make them pay for whatever covers their area.

I come from the wire-side, but spend a lot more time in the air now.

Good luck and keep sharing!

Regards,

--Bruce

[wififofum]

Hey John,

FYI - take this with a grain of Aruba salt, but its a pretty detailed technical argument against SCA.

http://www.arubanetworks.com/pdf/technology/whitepapers/wp_RFARCH.pdf