setting up temp wireless net for 300+ users

M

moro

Weaksauce
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Mar 8, 2005
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I just got the task of setting up a wireless network for 300-350 users in one large ballroom for a week long seminar. I have no equipment at this time. We will be setting up in a hotel ballroom. Wired is not an option. The hotel charges for every wired connection even through switches or our own routers, but does not charge for wireless connections. We tried negotiating and the hotel would not budge. $1,000 per wired connection for one week no discounts for large numbers. $300 to connect and $100 per day of use use per wired device. We are not paying $350,000 for one week of net access. Do it wireless and its $1,000 for each base station. Yeah its a gouge either way, but wireless is obviously much less.

So, Any suggestions? I have mostly worked with wireless nets of 50 or less users. I did some support on a much large wireless net but it was spread out over several buildings and never had more then 20-30 users on any one AP. This is going to be 300-350 people in one room. Tables will be classroom style. They will be using the network for internet access to view web pages. I don't expect heavy usage. (no streaming video etc)

We are doing this one time for one week so I don't want to fork out for a high end Enterprise solution if I don't have to. It does need to be reliable and just work. I will need access restriction of some kind weather PSK encryption or some PW based restriction.

Any suggestions thoughts?
 
30 users per AP is about the max that you will want to do, granted I have seen Cisco APs with 90 users, the performance is awful.

The next problem you run into is that you only have 3 wireless B channels that do not overlap (1,6,11) which would be 3 APs * 30 users = 90 users ... a far cry from 350 users.

You options: slim. Do all of your clients support 802.11A which has 8 non overlapping channels.

You should use intelligent APs and a wireless lan controller that can balance loads, change Tx/Rx power, and allow AP hopping.

The cheap way to do this, although it may have significant problems, is to purchase a dozen 'cheap' linksys APs, and crank down the power to the lowest levels possible and spread them out evenly over the conference. You could potentially return the APs to your local worst-buy if you don't see any problems with that.

As far as authentication, leave the APs completely open, and use a captive portal authentication system such as M0n0wall.
 
If you are using your own routers how will the hotel know how many wires your using, surley you can link a desktop to a desktop? is that allowed?
 
You could just get 10 ap's give them ssid's 00-01 to 00-10, write down 30 post'it notes for each ap with the ssid on them and hand them out to people on entry.
 
Always good info from archivalbackup. To add a bit more:

The design he is referring to is a BSS setup(basic service set) which pretty much allows for the most minimal/non existant service overlap. The problem with this lies in the fact that you WILL have dead spots and if not carefully prepared someone of the attendees at your conference may have little to no signal.

I think your best bet is to use an ESS(extended service set) architecture, just spread your channels out accordingly. If you're using B/G network, like archival stated there are only 3 non-overlapping channels so do something like this:

AP1(ch. 1) -- AP2(ch. 6) -- AP3(ch. 11) -- AP4(ch. 1)

going back to channel 1 is on option as long as that channel doesn't spread back into any other channel 1 freq. spectrum. Obviously this is where the "true" network engineering comes into play. Roaming is something that is very good these days, especially in our world full of pampered brats(CEO's, CIO's, CFO's, etc, etc)

If you can go with an .11A solution I would, you actually have 12 Non-overlapping channels , therefore the engineering becomes much easier. Also remember your distance limitations of .11A vs B/G.

Lastly, do not use PSK's. They are a hassle and will just piss people off(plus are easy to crack and induce overhead if you're using a soho solution). A RADIUS server with captive portal is a must. Keep everything unencrypted to keep overhead extremely low. Make everyone aware that the network is unencrypted as well.
 
I've done similar work for meetings/events, so I feel your pain. Nothing worse than paying hotel charges for internet or telephone charges. It does seem strange that they are not budging on the price at all; for an order that size there should be some negotiating room.

I second the recommendation for no encryption. Not worth the trouble.

How I would do it and have done it for smaller groups: DD-WRT flashed routers, bridged, wired to switches, wired to the tables. If the hotel tries to charge for the wired connections explain that they are a backup in case of dead spots, loss of signal, etc. I would have hardline backups in place (but not connected) just in case.

I personally don't like the idea of a fully wired/wireless meeting room for attendees, but I'm not sure, in your case, why the access is needed. For pure content delivery there's system out there like this that work very well. (I've seem that particular system in action a couple of times...very nice.) Not sure what the cost would be, but might be cheaper than you having to purchase and deploy the equipment yourself.

Hope this helps a little bit.
 
Thanks guys, Awesome input. Confirmed some of the things I was thinking and gave me some new info as well.
 
Are they charging per wired connection, or per IP address they give you on wired connections? If they want a grand for each IP they give you on their network, just get one, plug it into a router that can handle that many users - your cheapest option would be an old PC with a linux/bsd routing suite (IPCop/pfSense), and then just use your own switches & your own wires.
 
RavenD said:
Are they charging per wired connection, or per IP address they give you on wired connections? If they want a grand for each IP they give you on their network, just get one, plug it into a router that can handle that many users - your cheapest option would be an old PC with a linux/bsd routing suite (IPCop/pfSense), and then just use your own switches & your own wires.
Click to expand...

A lot of hotels/convention centers don't care if you use their wires, routers, etc. or your own. They view each wired connection as a charge; after all, it's traffic going over their network. I've been in hotels when they've come in and counted every computer to make sure they were charging us enough. A few times they've shut the connection down if they thought we had more connections that we had paid for.
 
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