Wireless overkill. That is what happens when there are way too many AP’s in a certain area. Or, when the AP’s are configured to scream at the loudest decibel possible and their voices overlap by miles. Well, not miles, but you know what I mean.
When we are rolling out more wireless infrastructure to support the endless growth of mobile devices – think tablets, phones, scanners, and other devices – it is often the assumption that more devices requiring more bandwidth (voice/video) with more critical traffic being delivered will require more AP’s. Well, that may be true in some cases. But in several environments, more AP’s doesn’t mean that we will get better wireless service.
Before changing anything on the wireless environment, know what you have, and what you need. Using a tool like the Fluke Networks Aircheck, we can quickly see what AP’s are in an area, and how much signal can be detected in a given area. This is an important step to take before deploying more AP’s, because it may be that our coverage is fine for the number of users we will realistically support. While doing this analysis, be sure to look at the interference levels to monitor not only the signal strength, but the quality. We can have great signal strength in an area, but if we have a lot of interference, then throughput will be low, and this will affect performance.
The reason why too many AP’s can be a bad thing, is because we can have channel overlap and crosstalk. Ever been in a noisy restaurant with someone else and tried to have an important conversation? That is exactly how a client feels when it is trying to communicate with an access point on channel 6, when there are 4 other AP’s on channel 6, as well as a couple on channel 3, 4, 6, and 7. You get the idea. If there is a bunch of noise in an area, clients have a hard time communicating. Noise goes up, interference goes up, and retries go up, which kills performance.
So before throwing out a bunch of new AP’s, look at your environment. Analyze what is really needed for good performance for the expected services and users. Then make the decision to either add, or in some cases subtract, the number of AP’s that will give the required service.
End the AP overkill! Only put out there what you need. There is such a thing as TOO MUCH of a good thing!
Author Profile - Chris Greer is a Network Analyst for Packet Pioneer. Chris has many years of experience in analyzing and troubleshooting networks. He regularly assists companies in tracking down the source of network and application performance problems using a variety of protocol analysis and monitoring tools including Wireshark. When he isn’t hunting down problems at the packet level, he can be found teaching various analysis workshops at Interop and other industry trade shows. Chris also delivers training and develops technical content for several analysis vendors. He can be contacted at chris (at) packetpioneer (dot) com.