It’s difficult to manage what you cannot see, which is why some network administrators struggle with Wi-Fi performance management. Here is a short list of factors affecting Wi-Fi performance:
Quantity of wireless access points
Quantity of SSIDs and devices
Use of legacy access points (802.11 a/b)
When analyzing the performance of your WLAN, there are places to look. However, your analysis may take you below the surface. Below is a list of areas to explore when analyzing Wi-Fi performance.
Learn more about how your wireless access point vendor does channel resource management. These automated plans run off algorithms, which are imperfect. This means that it is possible they get caught in a channel switching death spiral, which introduces instability to the system and can severely impact Wi-Fi performance.
When analyzing performance and wifi to optimize, consider using all of the spectrum that’s available to you. While it’s true that not all devices support 5GHz, do the best you can to utilize it.
Adjusting the power levels of your radios is not like turning the volume up in your car. Sure, people can hear you in the next car over, but you can become a nuisance too! Similarly, there is a sensitivity and moderation that must be learned when adjusting the power levels of your RF radios, or run the risk of making the environment worse. Ideally, you should lower output power and use antenna gain to reach clients further away at higher data rates.
But data rates that are too high can be unstable. This generally shows up in the form of high retry rates. Bring data rates down in “noisy” environments to provide stable, robust connections. In VoWLAN environments, you can also improve the robustness of your radios by assigning a higher Quality of Service (QoS) class.
Ripe for Wi-Fi optimization may be your WLAN controller. It’s possible that the hardware, software or both are in dire need of an upgrade. This is an easy Wi-Fi optimization. Just talk to your vendor and they’ll be happy to tell you all about their new products and software.
Sometimes the lights are on, but nobody’s home. Resetting access points in the area where complaints are coming from can be a fast fix. At the same time, consider checking the orientation of your antennas. When there is physical interference, such as concrete metal, a simple directional change may do the trick.
Be on the lookout for interference. It’s always present, though not always obvious. Bluetooth is the most common source of interference. It can come from keyboards, mice, headsets and handset readers. Use a spectrum analyzer to help identify the origin and attempt to correlate it to throughput for validation.
WirelessLAN Professionals Summit
Download Veli-Pekka Ketonen’s presentations on advanced Wi-Fi performance analysis from the WirelessLAN Professionals Summit in Texas.