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I wanted to get everyones opinions on some good wireless site survey apps. What have you used, liked, disliked? Specifically, has anyone used Proxim's "Ekahau Site Survey / Site Survey Pro", and if so, what was the experience?

Any insight would be appreciated.

Thanks.

I believe the Proxim version is the same as ESS, but I don't know for sure.

I have over 40 hours experience with ESS recording measurements, and more with design, and supervised site surveys where other people were using it. but I haven't used it much for the past year. So please take the following comments as a starting point only, for your own testing.

First, the good parts -
It makes very attractive signal strength maps compared with AirMagnet Survey Pro. It uses a grid of blocks for this purpose, and accuracy seems to drop if a drawing is really large, since the number of blocks is fixed. Ekahau didn't provide any hard and fast rules, but suggested repeatedly that my 100' x 400' drawings for floors were too large, and should be divided for better results.

The signal strength results appear to be smoothed in some manner, which is probably appropriate.

On a number of occasions I have taken a variety of client cards, used a beaconing AP without interference, had no physical movement in the environment, and gotten numerous RSSI values over a one minute period that vary by over 10 dBm (most within +/- 5 dBm). Some have been 20 dBm from the highest to lowest. Neither the AP nor client computer was in motion, and similar measurements were with Ekahau, AirMagnet Survey Pro, Cisco utility, and Orinoco utility, and included multiple samples of the same client card and different models of client WLAN PC cards. Standard deviation for these readings usually runs 4-5 dB. Variation and standard deviation can be reduced by about half if the AP is transmitting longer and more frequent frames than just the 100 msec beacons. Possibly like other people, I first used site survey APs set to standard beacons only, which gives lots of variation in RSSI readings from second to second.

Considering these observations, smoothing the results probably does not result in any loss of accuracy.

Now the other parts -
1. As of the last version I used for an actual site survey:
ESS ignored APs that weren't broadcasting an SSID, so even in the same facility, about 6 of 30 existing APs didn't get logged. It may be that the only APs that get logged are the ones that respond to a probe request that ESS is sending, and that send their SSID. Ekahau literature shows that some client card models will perform differently, but I did not get different results by changing client cards.

2. I have had problems with every version I used in getting clients installed and working under Windows XP. I have a lot of experience with applications and Windows, and used to teach MCSE classes. This is with several different computers and more than one model client card. Client operation, after it was running, was sometimes erratic.

Please bear in mind that these issues could have been corrected in the latest versions.

Charles Preston

Charles,

Thanks for the response. I suppose I won't really know the quirks until Ive used it. Here's the deal...the survey is for a mesh network over a small town. I understand I'll probably need to do it zone by zone, but I'd still like to have an accurate utility to use before going into the installment phase.

Thanks again for the input. I'll let you (all) know my results!

I now do site surveys by capturing throughput along with RSSI. Although there are other aspects of WLANs that could be measured for quality, and there is an IEEE group working on meaningful measurements, I think throughput is generally considered a good quality indicator.

Especially outdoors, where delay spread may be greater than indoors, throughput might provide more useful information than RSSI alone.

I've been using InFielder (Wireless Valley, now Motorola) to do this in a fairly simple way. There is a server laptop, and I use a TCP/IP connection to it from the mobile tablet InFielder client. I've been getting some interesting results.

I've used other throughput measurement methods, but InFielder makes it easier to capture lots of RSSI and throughput data points with location coordinates.

Charles Preston

For indoor Site Surveys Helium Networks Wireless Recon smokes everything else that I've used (including Ekahau and Infielder).

Bottom line, it takes thousands of samples automatically, compared to dozens or even hundreds by others.

For outdoors, Ekahua does have the GPS capability, so that might be a decent option, though I haven't tried it that way.