How to Read WiFi Heatmaps?
The image above shows a WiFi heatmap generated by NetSpot. Notice how different parts of the map have different colors. The color red means that the signal is very strong (hot), green means that the signal is average, and blue means that the signal is weak (cold). These three main colors create an endless array of possible color gradients, depicting raising or falling signal levels.
More specifically, the map above displays the signal-to-noise ratio (SNR), which compares the level of the WiFi signal to the level of background noise, which may be produced by microwave ovens, cordless phones, wireless game controllers, wireless video cameras, and many other electronic devices that can be found in most homes today.
SNR doesn’t include co-channel interference from other radio transmitters, which is where the signal-to-interference ratio (SIR) comes in. SIR is available as one of the premium visualizations in the PRO or Enterprise version of NetSpot.
Other visualizations available in the PRO version of NetSpot include signal level, quantity of access points, noise level, frequency band coverage, PHY mode coverage.
Signal level corresponds to the strength of your WiFi signal, and its purpose is to give you a better understanding of your signal-to-noise ratio (SNR). Quantity of access points shows the number of access points detectable at each measurement point on the map. Noise level is the amount of outside interference detected at each measurement point and it’s best understood in comparison to the signal-to-noise ratio.
Frequency band coverage shows you which frequency bands are present in the surveyed area. Finally, PHY mode coverage shows you which 802.11 protocols are present in your scanning area, including protocol overlap.
