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Hi all,

I am looking to design an 802.11n Wi-Fi setup for a bunch of lecture theatres and could really use a sanity check on my design methodology as I've not managed to dig out any useful stats on real world throughput expectations for 802.11n. (And with such varied environments, kit and device combinations i guess it's no suprise!)

So, I'd appreciate any feedback on my design principles below:-

3.1 USER REQUIREMENT ASSUMPTIONS
? Assuming that within a full lecture theatre, 50% of students may be using Wi-Fi at any one time
? Assuming that of these 50%, 50% again are actively sending/receiving data at one time
? Assuming 1Mbps of bandwidth required by each user for SD YouTube.

Total Bandwidth required = capacity / 4 * 1Mbps
? Assuming at least 50% of users have one Wi-Fi enabled device, and some users have 2

Total Associations to network = 1 x Lecture Theatre Capacity

AP CAPACITY ASSUMPTIONS

? 80% of uses connect to 2.4Ghz
? Assume 50% ?N capable Clients? on 2.4GHz
? 2.4GHz Radio using 20Mhz HT Channel, 2 Streams

Effective Max throughput of on 2.4GHz is 70Mbps per radio = 70 Clients

? Assuming 20% of of users connect to 5GHz
? Assume 80% ?N capable Clients? on 5GHz
? 5Ghz Radio using 40Mhz HT Channel, 2 Streams

Effective Max throughput of on 5.0GHz is 140Mbps per radio = 140 Clients
Therefore if we had a 300 seat theatre, we would need
300 * (80/100) / 70 = ~ 3.4 Radios on 2.4 GHz
300 * (20/100) / 140 = 0.4 Radios on 5 GHz

Lots of hideous assumptions made... but am I in the right ballpark? (Personally my gut feeling is that I'd need more than 4 2.4GHz radios...)

Any thoughts welcome!