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I am looking for examples of situations where a company did not perform an audit prior to installation. Therefore the installation had problems, tweaking for weeks/months and the customer was not happy. The installation had a lot of problems that could have been avoided with an audit.

By audit do you mean site survey?

GT

Yes. We conduct site visits(surveys). From this we then provide propagation surveys which encompasses mapping, designing, engineering and installation if needed. We are starting to expand our business and are looking for information/examples of companies that didn't use audit surveys prior to installation - and now wish they had.

Do you have any examples?

Thank you for your reply!

1/2 of the students that step foot into the classroom are in the spot. :) I don't have any specific examples, but I can say this: One of the new major problems in Wi-Fi is the deployment of too many AP's. I've heard many situations (again, non specific) where the consultant went in and shut down 1/2 to 2/3rd of the AP's and the network worked much better.

Sorry I couldn't be any more help.

GT

I agree with Gene. I've seen way to many site that had TOO MANY APs.

Why? They were designing with 'Coverage' only in mind. People might have done a pre-install 'Audit' or 'Survey'.

I don't really care about the pre-install survey. But you MUST do a post install verification survey to actually 'see' what is in the air.

The easiest of all is to get 'coverage'. The hardest? To minimize co-channel interference.

Most poor WLAN systems I've seen had fantastic coverage, too much coverage, so much coverage that there was so much co-channel interference.

Co-channel interference leads to an even worse problem. Collision domains! Where a single device talks, and multiple APs freeze waiting for the device to finish speaking. Thus a huge collision domain. (Or to use David Coleman's term 'Contention Domain')

This causes what most end-users call - "The wireless connection dropped" - and you'll spend hours trying to track down or duplicate the problem when it was traffic load induced, NOT coverage.

Post Install Surveys are a MUST!

Also - don't merely check RSSI, also check Overlap (double coverage or backup coverage at a specific RSSI), Channel Interference, Users per AP, and whatever other statistics your target client device demands.

Remember! RSSI is only the first of many important statistics you MUST check in order to trust your wireless LAN environment.

RSSI is to Wireless what Electrical Connectivity is to Wired. Required, but not nearly sufficient!

I heard about interesting new troubleshooting product, the Site Miner by 7signal. The idea is to put client imitating monitoring stations to the problematic site and let them collect performance data and even locate sources of interference with directional antennas. IMHO that could save a lot of time spent running around with a laptop...

What's your take on that?