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Best WAP For Dense Crowds?
An anonymous reader writes "A local community organization has asked me to help them set up Wi-Fi access for an upcoming event, with some unusual (to me) requirements. All users (up to 500 people) will occupy a relatively small area and more-or-less have line-of-sight to the WAP, so issues like signal strength and wall penetration don't matter. Security also does not matter, as we plan to open this to anyone wanting to connect. Cost always matters, but we realize a $50 Linksys or three won't cut it here.
In the past, I have used Cisco AP1200s for a few dozen users to great satisfaction, but they only handle 50 connections at a time, and practically count as antiques at this point anyway. My research on the matter tells me that 802.11n performs far better in this regard, but I want to support 802.11g as well. I have no objection to using two APs to split those apart (with n limited to 5.8GHz, as per the suggestion of several comments in a recent Ask Slashdot), but physical constraints make it preferable to minimize the total number of APs needed — Ten WRT54s might cost about the same as one Aironet, but I only have three good places to mount these.
I welcome any suggestions and real-world experiences with similar situations, including the ever-popular Ask Slashdot refrain of 'What kind of idiot would do it like that, when you can just do this?' Ideally, I would like to know model numbers and how well they held up under real-world loads comparable to my situation."
I thought WAP was dead with real mobile browsers?
You don't have to hit 'em, mate. Just find another crowd that's brighter.
Will all 500 users connect at the same time and continuously (like some type of LAN party w/o the LAN) or is this much more haphazard and random with far less users at any one time?
consider running a small pfsense box with a number of wifi adapters. You could pick up some cheap directional antennas to help limit connections to any one radio somewhat. Alternatively you could just run 4 sids and do a script to hide a sid when the user count got so high so the next users would only see the less loaded ones.
there was a slashdot the other day about the wifi at a python conference.
any AP is only going to handle 50 users or so because 802.11x is contention based.
So go ahead and get yourself 10 APs, spread them out, and make sure the ones near eachother are on different channels.
Even though they're suspected GPL offenders (opinions differ) I still have to put in my word for mikrotik. These guys know how to build wifi in rural areas with plenty of subscribers, stable hardware and good software at low cost. Even their cheaper products are very well up to the task and can be expanded upon with different wireless-transmitters and antennas. If that is not enough you can always look at their more "enterprise:ish" products. I've only good things to say about them, and we used their products for well over 5 years when we still ran a WISP.
I have a Netgear WNDR3700 that I use as an access point. It has a lot of good features including two independent radios (2.4 and 5 GHz), gigabit switch and a pretty fast processor. It is about as good as it gets for hardware of its type.
The firmware based on OpenWRT. Some of the features like the attached storage are dodgy, but that doesn't matter for this application.
For your application though - high density, lots of users why don't you take some of the load off the airwaves by offering wired connections too? People who aren't actually physically roaming will appreciate the choice and better performance of wired.
But I'd say, a few Aruba AP-105s (with 802.11abgn and band steering - which tries to put clients on the 5Ghz band), or maybe even AP125s (which have more MIMO) for the core. You can fill in the corners with cheap little AP-65s. The ARM (adaptive radio management, shoves clients from one AP to another or something like that) means that Aruba works very well in dense deployments. (You'll also need a controller behind them... probably an Aruba-200 or a 651 - the latter has a built in AP. Having the controller limits the configuration you'll need to do.)
I work for Aruba, but I never look at a price list. I believe, however, the pricing should be rather competitive with Cisco .... Also, I'd cite some super awesome deployments and customers but I forget who's a super awesome reference customer that my parents would recognize and who's just "a major hospitality win in the Middle East" (which is so much less impressive-sounding!) here's their press release page anyway.
Setup some inexpensive ipfire (ipfire.org) boxes with wlan cards. Can be used, older hardware and the distro is free.
I would suggest http://www.xirrus.com/products/
Run your favourite 3rd party firmware on it (openwrt, dd-wrt, tomato, whatever) - it's specs are pretty awesome for the bucks. 128M Ram, 32M flash, two usb ports, N wireless, 480Mhz Broadcom/MIPS cpu (~twice as fast as most others).
BlackNova Traders
and here's the press release about the Australian Open, whose organizers said
You may want to look into Aerohive. If you are interested in pricing or more technical information let me know http://www.aerohive.com/products/overview/hiveAP300.html
Not the cheapest stuff, but Meru's access points and controllers will allow you to run all the APs on one channel, and the controller "load balances" the users across the available access points within reach of the client.
We use them at my place of employment (6 APs scattered throughout the building servicing around 200 laptops), and the performance is quite good.
-ted
Xirrus 'Arrays' are designed for what you're doing. I've used 2 4-radio Xirrus arrays to serve 240 users in a single ballroom. http://store.xirrus.com/SearchResults.asp?Cat=4
Ubiquity Rocket M2 and M5
Scalability: 300+ subs per sectored base station
Xirrus is the way to go... I've done this before and nothing else has worked, especially Cisco. We have standard Xirrus conference kits at work ready to be quickly deployed for this kind of thing. Reasonably priced too.
The Xirrus XN8 not a cheap option, but it will work for over 500 simultaneous users with b,g,n using only the one device.
Ubiquiti (ubnt.com), makers of WISP hardware, have a "Bullet AP" product that is extremely affordable and VERY easy to set up. It's great in dense environments and you BYO antenna so you could set up 2 or 3 with panel antennas at a central location to cover the entire area, effectively load-balancing your geography.
Not the cheapest stuff, but... well, $marketing says that of the Adaptive Radio Management
What you are describing is basically the situation faced by every conference with more than a few hundred people. Everything is fine when you are in break-out rooms or smaller sessions, but put everyone together in a ballroom, add a boring keynote speaker (probability: high), and wireless becomes unusable. Especially geek conferences when every person in the room has a laptop and a iPhone. Or two. The usual solution is large numbers of WAPs and let the proles self-regulate which WAP they connect to: if they can't get one one, they'll try, try again until the connect.
use Adhoc. no problems then. eesh.
So you put 240 people in a single ballroom, and all they do is surf the web?
Why..? Did you forget to turn on the music?
Seriously, try Meraki. Their software is pretty neat, and it'll auto configure to give you the best situation.
A case study: http://meraki.com/general/2009/12/09/does-it-scale-absolutely-blazing-fast-meraki-wireless-at-leweb-conference-in-paris/
You will have to email them to get the Prices, but you could get all 500 of them by just using three of these. I can tell you from my own experience these will definatlly do the trick each once can handle 200 concurrent connections and have enough speed to run HD IPTV's off them if you wanted. http://www.ruckuswireless.com/products/zoneflex-high-end/7962
remember that they will all be able to listen to each other's traffic.
It won't have anywhere near the granularity in configurations, but I will say apple airport extreme's tend to "just work". They support both g and n operating at the same time since they have multiple antenna's, and they also have a sort of sandbox guest environment you can set.
If you want fall-down easy to setup and manage, they'll get the job done. If you want granular control, don't waste your time. I got sick of trying to make dd-wrt work with WAP, wireless-n and g at the same time a year ago, and just bit the bullet on the apple units. I can say it's been one purchase I don't regret.
They're going to use laptops in the mosh pit?
Background on me to qualify my comments: I am a cisco engineer specialising in wireless and security. My product recommendations later come from this experience but there are other products capable of the same performance such as the aruba equipment which would be my close second recommendation but i have no specific product knowledge.
I think you need to refine your requirements. It is highly unlikey that a crowd of 500 people will create 500 connections. You will probably end up serving 100-150 clients simultaneously but not all of them requesting data at the same time unless there is something specific that all users need to connect to at the same time throughout the event.
Without much better information everyone is just throwing out a product, not a design. And as you clearly are not a wireless expert (as you asked for 802.11n "as well as .11g) i would recommend finding someone who is to consult properly.
And for those suggesting consumer products, your dreaming. Without some form of spectrum management in this situation the asker is doomed to provide a very poor service with no roaming and massive 2.4ghz congestion. In addition, those people recommending wired access, WTF? You very clearly do not understand what you are talking about. Are you expecting 500 desks with RJ45 ports, or multiple 48 switches places around the room for people to huddle around with their laptops (and only laptops as no mobile device even has an RJ45 port). This is clearly a fallacious argument.
Answer the following questions and we can all get very specific.
3 points to place APs. Is this to physically mount or a cabling limitation? Can you mount more but have no cabling? Un-manged switches can help with this for less than $50 each. If only to mount then you are stuffed, There is nothing out there that will handle 500 clients with any useful service. It's not a limitation of the products it's the contention of the medium as mentioned earlier.
What services are they accessing? Are they local or is it just the internet? If the internet, what is the upstream bandwidth available? If local access at high speed (100Mb/s +) then you will end up with contention issues. If it is the internet and the pipe isn't fat you are not looking at contention issues you are looking at number of users connected. Most modern APs do not have practical limits of associated clients but most recommend around 25 per AP.
What is the nature of the event? Basically, are you providing a service that is required constantly throughout the event leading to 100% of attendees connecting all the time. Also, are users accessing a high bandwidth service (streaming video for example) all the time or things like static web pages delivered via http? The later will deliver small amounts of data to each person but will then take time to read by the attendees al will also be cached locally meaning subsequent connections will require even less bandwidth. If streaming video, someone should have though of this earlier and you will need a consultant/engineer 100% or expect to fail.
An off the cuff answer without the above knowledge assuming http type data required, cabling limitation not mounting, the more realistic 150 simultaneous users and internet link at less than 30Mb/s:
1x Cisco 2112 Controller (100Mb ports not important as limited upstream)
5-9x Cisco 1142 APs (very nice 802.11n dual band with the ability to force people to move to 5Ghz if they have it 6.0+ code)
3x gigabit unmanaged switches (something like dlink DGS-1005D)
It would not be far fetched to contact decent size Cisco/Aruba/VendorX partner and get loan equipment for a price + a consultant as part of the deal.
Check out Aerohive (http://www.aerohive.com). These guys use to work at Juniper/Netscreen. It's a controller based solution that runs CentOS with a MySQL backend. The APs themselves run Linux too. If the APs lose connectivity to the controller, they can still function. You can do 802.11x auth. Good stuff.
The chains of Cisco are removed, and an extraordinarily simple setup process - which will help you figure out AP placement and type, after uploading a site map, including all sorts of calculations that I'd really have a computer do.
I seriously recommend you take a serious look at Aruba Networks offerings.
Seriously.
Guns don't kill people, "with glowing hearts" kills people.
Baseball bats work quite well against one or two. Any more waps than that, you'll need to look for an alternative.
The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50
HP ProCurve has dual radio products from their buyout of Colubris... check out the MSM422. You can run 2-3 of these @ low to mid power with one radio on N (@ 5ghz) and one on b/g (channelized). That should split the traffic up a bit (most newer laptops have 802.11n cards) You should be able to get 200+ users per AP as long as no one tries to connect from the parking lot (hence the low power).
You can also use some narrow-field sector antennas and "columnize" your signals across a room.
If it is a more permanent installation, consider a distributed/engineered antenna solution (DAS) that will limit the signal bleed outside the intended area (and in turn, increase the connected capacity of the AP. DAS solutions get expensive though. So unless you have other signals you want to inject (cell, licensed radio, etc...), this may be out of the cost range you are looking at.
And for the record, I work for an HP reseller (we sell/support other vendors as well).
Never trust anyone who takes pride in being called a 'geek'....
Checkout the recent pycon conference setup. They had luck with 5.2GHz wireless A+N using netgear hardware. 600 clients. http://www.tummy.com/Community/Articles/pycon2010-network/
I hope you're not planning on buying anything when a better way to do things would be to rent/lease/hire some equipment for the job. Which is hard to place, since you gave so few details. 500 people, but what, if any networking connection will they need? What is the real intent here? I can understand being a little vague, but there's a point where it's hard to help, and it really seems like you're expecting a magic solution to waft you way.
Won't happen.
Setup 12 Airport Extremes Each one supports 2 different antennas plus a guest network. You can setup a group of them as N Only on 5Ghz, N Only on 2.5Ghz, G Only, B Only and maybe even setup one of them as A Only. Reasons I picked this 1, if you set WAPs up in N on 2.4Ghz with backwards compatibility it only takes one user on B to nock every one down to B. 2, There is a 50 User limit on WAPs 3, you get 24 networks with 12 devices, and you can space out the B,G and N 2.4Ghz networks over a few channels and have true 5ghz N and A there too. 4, They are high performance devices and reliable and easy to manage as a group. The other problem you will face is IP addresses. You will need to set that up to since you can only have 253 IPs on a class C subnetwork. Another reason I selected the Airport Extremes is you can build a wireless Network backbone so you dont have to string up cables between all of them. You can use the spare antenna on a few of them to connect to each other.
My firm loves and adores Trapeze WAPs. You can get MIMO units that are PoE powered for far less than the competition *cough* *cough* Cisco.
We have one prominent client (an IT admin who runs a large school campus) who swears by Trapeze WAPs.
Check them out: link
Keep in mind that only the best WAPs can only handle so many clients at once! You're going to need to have multiple WAPs on multiple channels in your area to make this work.
"--wine; a constant proof that God loves us, and loves to see us happy." --Benjamin Franklin
2x4 upside their head...it's amazing what some incentivizing can do to improve collective intelligence
You need to give us the following to help you:
1) db Antenna specs on the AP's
2) Area you would like to cover in cubic meters.
3) Are the sender and receivers using the same 802.11 spec or do you plan on mixing the environment?
4) Is this line of site for all of the receivers or are there obstructions?
Personally I have had excellent results with the WRT600. Nice big processor and decent antennas 802.11N, DD-WRT.
(You can modify the case to make better interfaces for Antennas...just google for it.)
-Hack
Got Geometrodynamics? Awe, too hard to figure out? Too bad.
Take a look at Xirrus access points... they're designed for high density applications.
However, they are expensive.
the best solution is to set up a lot of APs with very very low power and low gain antennas all over the room, in bridge mode, all with the same frequency and SSID, all connected to the same lan, and sprinkle them all around the room.
I've had very good results with Ubiquity picostation 2 attached to the chairs in a keynote style setup (one stage and plenty of chairs...
as for how it works, easy...
the "low power" part, takes care of there being a lot of people. laptop will connect to the closest ap (aka best received signal), so the lower the power the ap puts out, the less laptops it will attract (which will take care of the "I can't handle more than x people at a time part)
as for the bridging, frequency & ssid setups, this will allow for complete transparent roaming around the covered area.
ps: can I enquire what the event is ?
I addition to my other comments...
Turn off 802.11b. Very few devices still use it but if you enable it the backwards compatibility mechanisms will slow the network to a crawl. It is usually done by disabling the speeds 1, 2, 5.5 and 11Mb/s.
In such close proximity and no signal strength issues i would also recommend making sure you add higher basic rates ( i have no idea what vendors other than cisco call it) as if everyone is connecting faster (whether or not there is more throughput is irrelevant) then this will up the management and control traffic to a higher rate freeing up even more spectrum.
802.11n is compatible with all of the previous specs (a,b and g) even though they didn't all talk to each other. Mixed mode (2.4 and 5GHz to the rescue). Here are a couple links that should help explain (yes I know these are older but these should help get the idea across). http://features.techworld.com/mobile-wireless/2280/how-can-80211n-talk-to-all-worlds/ and http://www.pcworld.com/article/145098/new_80211n_routers_the_best_wifi_yet.html
Check out Ruckus Wireless. The dual band APs can handle 200 users each, and cover a 5000 square foot area each. They can be installed with or without a controller. Extremely easy to set up and they come with a lifetime warranty.
They have 17 directional antennas inside them and we have yet to find an environment where they did not out preform the competition; very strong signal and cut through interference like it isn't there.
We've been replacing Aruba, Cisco, and Meru products with Ruckus for many clients that have become frustrated with how difficult their existing gear was to install and manage. All of our clients are very happy with the Ruckus gear.
http://www.linksysbycisco.com/US/en/products/WRT610N
It should be less than $160 and will probably give you the best performance when using N. Never tried it though.
This: "Common man after the last time ... the lamp shade, two Chihuahuas and the weed waker, do you really have to ask?"
was meant to be a story about crazy behavior at a party:
"Come on, man... After the last time... The lamp shade, two Chihuahuas, and the weed whacker, do you really have to ask?"
check out prior art how to cater wireless to hundreds of network users, and consumer grade hardware isn't what you want
The Two-Tier Internet, Delivered by Anton Kapela
http://www.nanog.org/meetings/nanog38/presentations/kapela.pdf
Saw a presentation of the new Aruba 3 OS last week, and also got a demo of the AirWave used in the Aruba headquarter. This is a very good solution if you want to have full control and it's an event that you want to have control over and maybe have them on a regular basis. Could be that it's an overkill for this kind of event, but take a look here http://www.airwave.com/resources/demos/ to get a some new thoughts. It can also give you a heatmap of the coverage of all your AP's around in the event area.
http://www.merunetworks.com/ps/security/index.php
I would do a controller/WAP and possibly a router for everyone to authenticate too. But then again, 500 users on wifi is like beating a dead horse... Nothing beats hard wiring to every user. I would say if this is something like a large business, large RV park, Apartment complex, etc, I say bite the bullet and invest in the right hardware to do the job. Consumer grade products are not going to get you anywhere. So enterprise grade or bust here. You can probably run fiber optic to each corner and a few in the middle, connect to a small switch and hard wire where ever or attach your WAP and run them 100M in what ever direction.Shielded cat6 comes to mind for this task.
Good luck setting up 500 users on Stable wifi in the same community, because if you can do it, patent the method...
I have read very good recommendations of having cells of WIFI routers giving 1,4,7,11 in one, 2,5,8,12 in another and 3,6,9 in the third, why lock yourself in?
In Japan, you can use all the 14 WIFI channels, and if your event is the ONE TIME thingy, use all 14 channels !
Do a 1,5,9,13 on router A, then 2,6,10,14 on router B, then 3,7,11 on router C and 4,8,12 on router D on group them into one cell.
Try push all the users of router C and D to 5 GHz band, router B to 3.6 GHz band and router A to 2.4 GHz band.
Use directional antennas, aim router A to North, router B to East, router C to South and router D to West.
Then set up cells within the premise.
In that way the signals that overlaps are not of the same channel, and not in the same frequency band either.
Muchas Gracias, Señor Edward Snowden !
If you need 500 simultaneous users, you should consider that 1 ap will not handle more than about 50 simultaneous well, if so many at all. So, you need arround 10 APs. I suggest proxim AP-4000M, which is about 600$ per AP...sorry not realy cheap, but neither are your requirements.
What kind of gathering would require a pure wi-fi solution? Is everyone using smartphones or tablet PCs? Do they need to move around? If this is your typical conference/meeting where people are rooted to one spot with their notebooks, you may want to consider wired connections, in addition to wi-fi. WAPs are cheap these days, but Ethernet switches are also cheap, and possibly cheaper. For e.g. you can buy well-known brand 16-port switches for about $60 ea. Plus you don't need to buy "enterprise-grade" switches either - any ole switch should be able to outperform an 802.11g WAP. There might be a bit of problem with providing Ethernet cables, but you could always ask everyone to BYOC.
My brain got hung up on that thought for a while trying to figure out if it would even be possible to fit that many devices in my bathroom.
Mit der Dummheit kämpfen Götter selbst vergebens
Subject says it all.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
...CAT-5 based internet connection is probably still the best option. Why are you discarding it ?!?
With 500 people in a small area, why not offer Ethernet as an alternative, together with access points for e.g. 300 users, if the room allows for it (e.g. if you have tables, not just rows of chairs)? It will be faster for many users (if not all, considering the limited spectrum you have available), easier to set up, more secure and it's also possibly healthier (some of your users might be worried about emissions?). Of course, it is also much, much cheaper. For the first 2 reasons I'd always prefer Ethernet myself if both were available (could be just me though).
"I love my job, but I hate talking to people like you" (Freddie Mercury)
This isn't really that hard, even the old 802.11b service can handle this, a few years ago I worked for an ISP that serviced hotels and we setup these networks all the time. I even have a couple of patents on wireless security. The suggestions to use all 14 channels, lowering the power output with the same SSID works. You do want to physically separate the access points. Some people erroneously think that more power gets more connections. What you really are concerned with is that everyone on the same channel has to listen to all the other traffic from the other computers on the same channel. People also think that since channels 1, 6 and 11 don't overlap in frequency, that they are the only channels to use. The channels that overlap cause noise, but normally don't cause the clients to drop off. Get yourself a spectrum analyzer. I use Wi-spi from Metageeks which only costs about $200, you may want a couple. Next position your access points so that the close frequencies are furthest away from each other. Your goal is to create 14 overlapping circles of wireless activity that will cause the least interference with each other. In a single big ballroom you can draw a plan on paper in a box and figure it out. If it is a really big space there are usually support beams that you can also use. Walls, depending on the building material can cause your signal to do things you don't expect, so you need to get into the space and take some readings. I've seen some reenforced concrete walls kill most of the signal so that we could reuse channels right outside the room, while other walls allow most of the power to pass right through. We've also seen where we could actually place an access point outside on a light post and get great connectivity through windows. We've done this with multiple brands of access points, with good success. One other thing, don't forget the connection to the outside. A single T1 will not cut it for 500 users. Most services now don't care about being NATted, but its good to know if your presenter wants a dedicated IP.
Call the vendors of the type of product you are looking for and ask them what they recommend.
> Finally, if at all possible, make sure your DHCP server sends ACK using unicast where possible. AFAIK, every major OS should be able to handle this
Windows Vista by default (stupidly/evilly pick one) sets the broadcast flag for DHCP, so it requires broadcast responses. While it can handle unicast replies if configured accordingly, by default it doesn't ask for unicast replies and thus should not be getting unicast replies.
See: http://support.microsoft.com/kb/928233
Windows 7 probably handles it better: http://blogs.technet.com/teamdhcp/archive/2009/02/12/dhcp-broadcast-flag-handling-in-windows-7.aspx
That said, "default Vista" is OK with "broadcast replies" which are are unicast layer 2 (dest= mac address of vista machine) but broadcast layer 3 (dest=255.255.255.255). This may or may not be RFC compliant (in my reading the RFC is not very specific on this), but it works.
How I know this? Because in my previous workplace (which supplied "expensive hotel/airport internet") I wrote a dhcp server which was somewhat RFC compliant (and did work with Vista unlike some other dhcp servers ;) ), but I had to deal with a scenario where some network devices between the client and server were not forwarding layer 2 broadcast frames (they were supposed to) - so the dhcp replies never reached the vista clients. Fixing the devices in time was not possible, so I worked around it by doing the above.
If 802.11 broadcasts are that expensive (I can see why it would be different from unicast but are there any decent articles on that? ), then it looks like that feature would be useful in this scenario too - since you then send a 802.11 unicast but have the dest IP = 255.255.255.255. :)
Not sure if some patent troll has patented that already - to me it's just an obvious solution.
I don't see a good technical reason why Vista (or other DHCP client) should use broadcasts by default though.
And I wonder though how many laptop users are actually using Vista and sticking with it, instead of moving to Windows 7?
We've been testing some Ruckus 7962 APs and they are putting our existing Cisco 1242s to shame. We've also been happy with the controller and overall system config (our eval is with a ZD1000, but we'd be purchasing a ZD3000). We will most likely be dumping our current Cisco wifi infrastructure and going with Ruckus. Pricing is also excellent, especially when you consider what you get with the 7962s and the deals (sales) they run. We considered other wireless vendors, but after looking at all the technologies, we found they all pretty much do RF the same, except Ruckus. This is starting to sound like a commercial, but I'm just a happy end-user, and I've only had the eval equipment about a week. Here's their web site: http://www.ruckuswireless.com/
One thing i haven't seen suggested is adjusting the transmission power. It won't help if you are limited to 3 mount points though. By decreasing the transmission power on each AP, you are able to limit the cell size. This would allow you to pack more APs in a smaller area, without causing interference, and spread the load.
1. Push everything into 5.8 range you can. Whereas 2.4 (b/g/cheap N) only has 3-4 non-contiguous channels, 5.8 (A/N) has dozens of fully non-shared channels available which should make spectrum contention less of an issue in this band.
2. depending on the geographical area required, back the power levels down using either commercial gear that allows it by default or using one of the freeware (DDWRT/Tomato) firmwares so that it doesn't exacerbate cross AP contention in B/G ranges
3. Directional antennas
4. Disable the DHCP servers in your APs and setup 2 or more subnets with their own physically separate DHCP servers.
5. If there is any AP placement flexibility, it is generally better to setup an "edges in" approach with say directional APs antenna at the perimeter and at least 4 quadrants in the central area, though if this is in the US your going to be limited to 3 non-overlapping B/G bands.
There is a diagram in the Cisco CCNA wifi study materials that has a frequency reuse map defined for maximum spectral efficiency and minimum overlap, though with only 3 mount points you won't be able to use much of that.
As far as the per user available bandwidth being small and latency going up exponentially with more users .. on paper that's true, but I find it extraordinarily unlikely that ALL users will be powering up and attempting to access all at the same time. If this were really the case than I'd say scrap the AP plan and go scounge up some 10/100 switches and go wired.
no seriously, I started with a few dozen, built up a lab of 11,000 then did many tests with 32,000
this was all with Ad-Hoc, on 802.11 B, yes "B". on one channel!
it's all in how you do it.
yes, I wrote the protocol myself, it was called "L2R" and no you wont find mine with google,
that one isn't it.
You will not be able to accomplish your goals with consumer-grade equipment, simply because consumer-grade equipment is neither designed, nor priced, for this type of performance.
As a few others have suggested, Aruba Networks is a great solution, but it is neither inexpensive, nor simple/fast to set up if you don't know what you are doing. I've set up Aruba gear for a WAN spanning 30+ countries and supporting over 2000 users, and it is absolutely rock solid, with no performance problems whatsoever. The controllers intelligently move users to the least-utilized AP without packet loss, and load balance not just user count but by activity, signal strength/interference, etc.
You could pick up an 800-series controller for around $3000, but your user count might justify a 3000-series. The AP125 model supports a/b/g/n, and runs somewhere in the neighborhood of $800 each. Yes, it is expensive. The problem you are going to run into is that pretty much any AP is not going to support more than about 50 simultaneous connections, and really you are going to want to get that number closer to 25 users/AP.
Having separate SSIDs per frequency band is not a bad idea, but isn't necessary if you have a system like Aruba that does intelligent balancing.
One product that should possibly be used would be the Extricom. Their product line should be capable of doing this, but one must remember the recommended number of users/AP is about 10 to 20. The requirement for extricom, would be that you must purchase their switch with the AP, as the Switch manages the AP's to provide continuous coverage.
only room for 3 APs?
500 people?
WOW! sounds like a BIG microwave oven.
i guess one can surf the net by just
closing ones eyes in that environment
in your situation i would suggest getting a Bulk reel of Cat6, fittings, PROPER CRIMPERS and then a bunch of that wire channel stuff and then some rack type routers
(hint folks i did say crimpers as in more than one)
Any person using FTFY or editing my postings agrees to a US$50.00 charge
There was a slashdot post two days ago describing how PyCon 2010 did it: http://mobile.slashdot.org/story/10/03/04/1315210/Why-PyCon-2010s-Conference-Wi-Fi-Didnt-Melt-Down
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
-- You can't drink all day. (Unless you start in the morning...)
Use more WAPs and adjust the TX power down - then you can have greater density.
BlackNova Traders
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You could place a few OpenMesh units around the area. http://www.open-mesh.com/store/
Hey everyone. I'm a software engineer at Meraki (mentioned earlier in the thread by dotwaffle) and wanted to chime in and offer what I can. Our gear is commonly used at conferences, including the most recent LeWeb, a conference in Paris with about 2,000 attendees and VERY heavy WiFi use (social media types that are tweeting, blogging, posting photos and accessing WiFi from their cell phones and laptops). We covered a 12,000 square foot room and other areas without any downtime or customer complaints. This was a huge improvement over the 2008 conference, when poor WiFi topped the list of attendee complaints.
Dotwaffle posted a link to our blog post about LeWeb which is worth re-linking. That photo was taken when the speaker asked everyone to hold up their iPhone.
We used MR14 access points with channel spreading and band steering enabled. This allowed us to use the entire wireless spectrum and avoid congestion on a single frequency (both of these are 1-click options when configuring your network). I'm happy to answer any technical questions you might have, or you can visit our website to learn more.