Sat Feb 18, 2012 8:58 pm
Your biggest problem will be RF interference between access points, this will limit the throughput and the total number of clients more than the number of clients per access point.
At 2.4GHz you have 3 usable channels: 1, 6 and 11 and you need to arrange the access points to minimise interference between them. Use walls etc to maximise isolation between access points which are operating on the same frequency. Your target should be that signals from the nearest adjacent access point on the same frequency should be 30dB below that of the clients registered on your access point. In practice this is nearly impossible. Consider using directional antennas to reduce the coverage area of access points and reduce power to match the antenna gain. Consider the hidden node problem when working out coverage.
I recommend that you design the layout based on your calculated range to clients suggest you plan for +16dBm isotropic from the clients, maybe lower if they are mostly iPhones, Androds etc. Reduce the power of your access points to match this after allowing for antenna gain. There is no point using more power on the access point than is being radiated by the clients as you will end up with a link imbalance and interference to other access points.
Enable 5GHz and use as many channels as practical (or DFS if you have to). Use the same ERP power settings as 2.4GHz. If you get 2.4GHz coverage correct then the coverage at 5GHz will be about right too - the difference in path loss is insignificant as interference is your biggest issue.
When you have done all this you can compute the maximum number of clients per access point, users will not be distributed evenly so allow a margin for this.
I can try to advise further if you let me have more information and a floor plan. Please contact me directly if the details are sensitive.
regards
andy