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http://www.cwnp.com/podcasts/SiteSurvey.mp3

Feedback please. thanks!

Devinator

Excellent overview of site surveys. In fact, I've sent the link to a few net admins who've been sending me e-mails asking about more specifics in this area.

I only have one question. Devin, you said - right at the end - that manual site surveys are already obsolete in your opinion. I've been hearing this from a lot of other sources as well. However, I have this question: What about the really - and I mean really - small companies?

For example, I've installed wireless networks in better than a dozen businesses that are in less than 1500 square feet of space and have fewer than 10 computers in the last three months. Gathering blueprints and materials specs would take days, but I can do a quick manual site survey in a matter of minutes.

I know most don't consider these "site surveys" because you usually use just one or two APs, but the reality is that I've seen a ton of implementations that were just plain wrong because no one analyzed the RF-space and ensured that the client could use the technology and configuration parameters used.

Just a thought. I agree that predictive modeling is the wave of the future (until the wave of "proactive planning" begins) for the enterprise, but what about these little guys? What do you think, Devin?

-Tom Carpenter

P.S. - Proactive planning is the term I've been using for the future where no building is ever constructed or remodeled without considering the building's impact on wireless communications in the area and within the structure. I see this happening in the next 10-15 years through actual building code mandates. This will force materials to be used that complement indoor wireless communications, but also act as a sort of barrier to communications leakage. Call it "faraday drywall". I kill myself!

Hi Tom,

Great questions.

Not all predictive/automated surveys include things as detailed as gathering building blueprints and materials specifications. Using your example, let's say you go with Symbol's WS-2000 WLAN controller and 3 thin APs to cover the entire facility. This switch (and practically all like it) has a feature whereby you just tell the switch to set the power output and channels automatically (w/o admin intervention). It scans the ISM and UNII bands and sees what interference (narrowband, wideband, 802.11, etc) sources it sees, and then chooses the best channels and power output for each AP. In addition, if the environment changes, then the switch can change the power/channel settings of each AP periodically. Aruba, as another example, calls this Adaptive Resource Management (ARM). This method of "site surveying" is basically allowing your WLAN controller to act as a glorified spectrum analyzer, making your decisions of power/channel for you. I personally still think that a manual walkthrough looking for RF interference sources using a spectrum analyzer should be done if it's economical (perhaps with a tool like Cognio's laptop-based platform).

Devin