Serving 10,000 simultaneous users over Wifi
I'm looking to offer a wifi service at a public event. The traffic will be very minimal, 10KBps should be adequate. Users don't necessarily need to connect to anything other than the private intranet.
Assume that all 10k users will be using the network at the same time, where would I start looking for a solution for this?
You're going to want to get in touch with a major vendor like Cisco or Aruba.
When you get that many people in a contained area, throughput isn't your (main) problem, interference is. For a deployment like this, you're going to need a large volume of APs capable of real-time channel select based on interference and auto-power adjust based on proximity to friendly neighbor APs. I know that most of the Cisco controller-based lightweight APs do this. I don't know if their autonomous line can, but even if they could, managing that many autonomous APs would be a headache in itself.
We don't do specific product recommendations on Server Fault, but I can tell you that trying to cheap out is only going to cause you to fail miserably. It's going to cost a lot and you're going to want to go with a major vendor that caters to large deployments.
You should also do your best to offer wired connections wherever possible to alleviate the load on the wireless network. 802.11 just isn't designed to have 10k concurrent users in their same confined space. If you have vendor tables/presenter rooms, give them switch ports and Cat5e/6 to plug in with (lots of people don't travel with these any more).
edit: Another advantage to going with high-end gear is that it can make clients "prefer" 5GHz A/N, which will also help alleviate some of the interference problems. Cisco APs can be configured to ignore the first X B/G probes and only respond to A/N probes. Usually configuring this where X = 3 is enough to get a bulk of users onto the 5GHz band while not lengthening association times by more than a second or two. The more users that you can push the the 5GHz band, the better. It'll still be crowded with that many users, but you won't have to compete with all of the 2.4GHz noise that is much more common than 5GHz noise.
I'm sure that other enterprise-grade APs can be configured in a similar fashion, but I'm only familiar with Cisco gear in the wireless space.
I guess this will be quite a huge task that you're facing...
After watching a co-worker at my university struggle with setting up conference wifi für a few hundred users, I read a few excellent articles about this:
- Joel Spolsky's "The WiFi at Conferences Problem"
- a good discussion here on Serverfault: "Why is Internet access... always so terrible at large tech conferences?"
- The reports from the PyCon organizers
- Also, look for the reports of the people who organize the Chaos Communication Congress (I don't have a link handy right now).