A WiFi heatmap overlays a graphical depiction of WiFi signal strength on top of a map of some real physical space, such as your home or office. When you look at a WiFi heatmap, you can instantly see where the WiFi signal is strongest and where it’s so weak that even tasks that don’t require too much bandwidth, such as sending email messages, are barely doable.
As you can probably imagine, having an accurate WiFi heatmap at hand is indispensable when planning and setting up a WiFi network. Without the ability to see where strong signal levels end and weak signal levels begin, it’s impossible to select the best place for the wireless router to ensure that the entire area is evenly covered.
WiFi heat map may sound complicated and difficult to understand and create, but that couldn’t be further from the truth. Thanks to modern WiFi heatmappers like NetSpot, anyone can create a detailed WiFi heat maps in a matter of minutes and understand them at a glance.
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.
NetSpot is an easy-to-use WiFi heatmapper that was designed to simplify the process of creating WiFi heatmaps as much as possible. To create a WiFi heatmap with NetSpot, you first need to activate the Survey mode using the slider located at the top of the main window.
Then, click the "Start a new survey" button and name your WiFi heatmap. You will be asked to choose Zone Area Type, which helps NetSpot configure default sampling settings for the first zone you create within the project.
If you have a map of the area you would like to survey, now is the time to load it. If you don’t have any, you can create one using the tools that come with NetSpot.
Once you’re ready to start the heat mapping process, click “Continue” and carry your laptop from one spot on the map to the next until the entire area is covered with green, overlapping circles. You can then click the “Stop scan” button and view the results.
The default view shows the signal-to-noise ratio, but you can switch to other visualizations supported by NetSpot, such as signal-to-interference ratio or frequency band coverage, by clicking on the currently selected visualization and choosing a different one from the list.
It’s worth mentioning that NetSpot is also the Android WiFi heatmap app, so make sure to give it a try if you own a mobile phone or tablet.
The easiest way how to fix signal weak spots is with better router placement. Avoid placing your router inside cabinets, near windows, behind furniture, or in hard-to-reach corners. Ideally, your router should be right in the center of your house, apartment, or office.
If you can’t place your router in the center of your space, you may want to consider purchasing a WiFi extender, which is an electronic device that repeats the wireless signal from your router to expand its coverage. WiFi extenders are relatively inexpensive, and their only inconvenience is the fact that they create a separate WiFi network.
To avoid constantly switching between two different WiFi networks, you can instead purchase a brand-new WiFi router, preferably one with support for the 2.4 GHz and 5 GHz WiFi band. High-end WiFi routers are equipped with multiple antennas, and they are able to focus the WiFi signal to connected devices with a technique called beamforming.
Of course, even the best WiFi router on the market won’t fix all signal weak spots unless you configure it properly and use a WiFi channel that’s not occupied too much.
NetSpot’s Discover mode takes a quick snapshot of nearby WiFi networks and presents wireless data as an interactive table, allowing you to instantly see which WiFi channels are used the most, both in the 2.4 GHz and 5 GHz band.