Wow, that's a string of misguided replies, with the occasional person that actually knows what they're talking about. Full disclosure: I'm an engineer for Aruba Networks, and this is exactly the kind of thing I/we do regularly. I've personally done the Interop shows in Javitts Center in NYC, the All-Star Game at Yankee Stadium, and various other conferences with 1,000 or more people. As a company, we've done the wireless network at Black Hat for years (without one failure or hack), the HoPe conference, as well as most of the hotels and conference centers in Vegas. Oh yeah, and every US Air Force base in the world. If you want this to work, here are the unique features that ONLY Aruba Networks provides for high density deployments (all without needing software on the clients or CCX extensions in the NIC card)...
- Band Steering: Use dual-radio access points. The Aruba gear detects if a client supports both 2.4g and 5g, and moves the client automatically to the 5g band, which is cleaner and has more channels available.
- Spectrum Load Balancing: Every vendor offers load balancing: there are 10 users on AP-1/Channel 1, and 20 on AP-2/Channel 6, so put the next user on AP-1. This ignores the fact that the only resource you're really constrained by is the amount of spectrum in use, not the number of users on an AP. If those 10 users are using most of the spectrum of Channel 1, while Channel 6 isn't being used as heavily by the 20 users, you'll get better performance by balancing the user to the less-utilized spectrum, rather than the lowest user-count AP.
- Co-Channel Interference: The Aruba architecture knows when a client is within range of two APs on the same channel, and schedules transmissions out of the APs so they don't collide in the air.
- Adjacent channel interference: Aruba ecognizes that there *will* be some bleed between transmissions on adjacent channels, and manages transmissions to avoid that.
- Airtime Fairness: Aruba recognizes the different client phy types (802.11a, b, g, and n-2.4/n-5) and allocates certain amounts of airtime to each client, so those old 11b clients don't drag your 11n clients to a screeching halt.
- Channel Reuse: modifying the collision threshold on the channel to allow you to reuse channels in much closer proximity to one another than normally possible.
- Dynamic Multicast Optimization: The APs can detect a multicast stream and determine if it's better to send the stream to all multicast clients at one, but at the normal lowest data rate, or convert the stream to a series of unicast transmissions that can be sent to each client at a much higher rate.
- Mode-aware Adaptive Radio Management: Deploy as many APs as you want. The Aruba architecture will automatically turn on (or off!) individual radios based upon RF needs; too much RF is worse than not enough, in most cases.
- Client bandwidth contracts: Set a rate limit for each user, so one person can't use half your bandwidth.
- Policy Enforcement Firewall: Allow your users to only do what protocols you want (http, https, dhcp, dns), and block all the others. iTunes/Bonjour/MulticastDNS from Apple products will KILL your network otherwise.
If you want more information on the physics of these methods, check out this white paper which has more info than you'll want to read:
http://www.arubanetworks.com/pdf/technology/whitepapers/wp_ARM_EnterpriseWLAN.pdf
Now, all of that said, here are some BAD ideas that people have suggested:
- Use all 14 channels!
------ Not only is this illegal almost everywhere, but most clients will use the operating system's country code and only use the channels that are supposed to be available. In the U.S. for example, only channels 1-11 are valid; client devices won't try to use channels 12-14.
- Use channels 1, 4, 7, 10 on one group of APs, then 2, 5, 8, 11 on the next set....
------ TERRIBLE idea. Because 802.11a/b/g transmission are roughly 22mHz wide, you can't transmit on channel 6 without affecting channels 4, 5, 7, and 8. That model will bring the entire network to a screeching halt.
- Use the 3.6gHz band too
------ This is not spectrum that is available for your use; the AP radios can't physically use it, and neither can your clients. This one is borderline crazy...
- Set up one AP on 11b, another on 11g, another on 11n/2.4, etc.
------ Again, just silly. It ignores the fact that they will all contend for the same frequency; that's the one and only resource you don't have enough of! Putting more APs in here won't help.
In the end, you left too many questions unanswered for me to get much more specific. What country is this in? How big is the space? Why can you only use 3 spots? Where are the three spots? How many *simultaneous* users will you have? What will they try to access? What do you WANT them to access? And what's your budget for all of this?
Good luck... reach out to me or your local Aruba rep if you want more info or assistance...
Michael
