WLAN Access Points Only Hear Half the Story

In a previous article, we discussed the importance of passive testing to understand how end-users are experiencing the Wi-Fi network. Some of you may be thinking that access points can do the same thing. In fact, they do collect some of the same information that 7signal's Sapphire Eye does. However, there are several advantages to 7signal’s architecture that enables the most useful and accurate measurements, which are critical for Wi-Fi performance management. Below are 5 ways the Sapphire system outperforms WLAN access points when it comes to monitoring and measuring the air.

1. The Sapphire Eye dedicates 100% of its processing power and air time to monitoring and measuring key performance indicators. The Eye operates in this mode continuously and collects data 24 hours a day.
2. WLAN access points are limited as sensors because they can only hear themselves while they are talking. In practice, they cannot listen to any activity in the RF environment while serving and transmitting data to clients.
3. Another important distinction is that a WLAN access point is only capable of monitoring traffic on the channel where it is currently operating. Since access points need to serve clients as a primary responsibility, they can only scan other channels for availability for a brief moment of time. However, when traffic volumes increase, there is no time for scanning other channels at all. This is unfortunate because peak traffic volume is the time when collecting the data is most critical. Optimizing a Wi-Fi network based on data collected outside of peak times does not provide reliable Wi-Fi analytics.
4. If you placed an access point into "listen-only" mode, essentially turning it into a full time passive sensor, it still performs poorly because it does not have the benefit of 7signal’s directional antennae technology. Directional antennae focus on one sector at a time while suppressing energy received from elsewhere. This allows the Eye to "hear" transmissions from larger distances, at lower levels and to collect valuable information that would otherwise not be detected.
5. Finally, 7signal offers another unique element, which is the tracking and trending of all the data collected over time. These Wi-Fi analytics are invaluable because they help identify coverage and user experience issues. Trends and patterns may point to issues taking place at a particular time or day of the week. These issues may coincide with particular events or activities taking place in the environment, planned and unplanned. Without the historical data and its visual representation in the form of a Wi-Fi performance management dashboard, network engineers are most likely left in the dark.

While it is true that WLAN access points can collect some data, they only hear half the story. It is not enough data in order to accurately diagnose performance issues. And without the data, there is little hope for Wi-Fi optimization or long term Wi-Fi assurance.