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Have any of you guys completed any 802.11n surveys? If so, can you explain what specs you used as far as SNR, data rates, etc. What tools did you use to test? We are currently preparing to do a large project and I wanted to see what you guys had run into. I can't find many answers relating to 802.11n. We will be using the 5GHz spectrum so I was thinking I could do the survey similar to what we have done in the past for a 802.11a survey. We are more concerned with capacity and throughput versus coverage area. Do you guys have any advice? Thanks!

I've done several large-scale 802.11n site surveys and found that the methods used for legacy networks still mostly apply to 802.11n deployments. I primarily use AirMagnet tools. The minimum SNR for defining signal coverage depends on the environment. Typically, I use 20 dB, but some environments with higher multipath and fading due to moving obstacles require higher SNR, such as 25 dB. In general, I recommend 25 dB for voice over WLAN applications. 802.11n signal propagation is much different and not as predictable as compared to legacy wireless networks, so you might have troubles determining optimum access point locations initially.

You might consider viewing an audio-visual recording of a webinar I recently completed where I discuss tips on selecting tools and determining optimum locations for access points for covering multi-floor facilities and elevators. You can view the webinar at the following URL: http://www.wireless-nets.com/training/wireless_survey_tips.html.

I've done several 802.11n surveys using AirMagnet as well. I'd recommend looking at the intended product documentation for criteria such as Signal Strength or SNR. This should be available from the hardware vendor. The Data Rate to aim for should be determined by the traffic/applications the wireless network is to support.

For me, this worked out to around voice requirements (20-25dB SNR depending on environment, as Jim said) using Cisco hardware.