What is Heat map (WiFi heat map)?
A WiFi heat map draws a wireless measurement onto a floor plan. Colors run from strong to weak, so a reader can see at a glance where coverage is good, where there are gaps, and where signals overlap or compete.
A heat map is the output of a survey, not the survey itself. It can come from a predictive survey, where software models the signal, or from a measured survey, where an engineer walks the area with a measurement device. A single survey usually produces several maps, for example signal strength, signal to noise ratio, channel overlap and estimated data rate.
A heat map needs context to read correctly. The same colors can mean different things in different maps. The thresholds behind the colors, such as the signal level shown as good, should be set from the requirements for the devices and applications on the network.
How it shows up in practice
- Ask for the legend and thresholds with every map, and confirm they match your requirements.
- Request more than the signal strength map. Maps for interference, overlap and data rate often show problems that signal strength hides.
- Check the date and conditions of a measured survey, because furniture, stock levels and walls can change results.
- Keep heat maps with the project files so they can be compared after changes to access points.