When setting up and maintaining a wireless network, you'll want to maintain good signal strength in all areas within the network perimeter. "Dead" spots of weak signal strength can cause connections to be dropped. With more and more people moving around while connected to the Internet through their smartphone or tablet, these dead spots have become more problematic.
NetSpot is a wireless signal assessment and site survey application for Mac. It provides two ways of measuring your WLAN signal strength.
The first — and quickest — way is to use Discover Mode:
If you just need to measure your wireless network signal strength in one location, then Discover Mode is all you need. However, if you wish to measure signal strength throughout your network area, you'll want to do a full site survey. This is how to do it:
Apple’s macOS and Microsoft’s Windows come with built-in support for wireless network connections and corresponding utilities that allow users to connect to WiFi networks and measure WiFi signal strength. These utilities are arguably the quickest and easiest way how to measure the strength of a wireless network, but their accuracy tends to be subpar, which is why we can’t recommend them over NetSpot.
This is how to use the built-in WiFi signal strength utility on macOS:
You can also try other Window options, like Scan or Performance, to see other useful diagnostic information.
This is how to measure WiFi signal strength on Windows:
Of course, you can always simply click on the WiFi indicator icon located in the taskbar on Windows and macOS and count the number of solid bars.
An online internet speed test won’t actually be able to measure your WiFi signal strength, but they can tell you the maximum download and upload speeds your internet connection can achieve. By comparing the measured speeds with the speeds declared by your internet service provider, you can get a pretty good idea about the strength of the WiFi signal in your location.
Just keep in mind that there are many other factors that can potentially influence your download and upload speeds, such as the software you run, number of users on your network, ISP network bottlenecks, and more.
To measure your download and upload speeds using an online speed test:
Speedtest by Ookla is just one of many internet speed test applications that are readily available online. Popular alternatives to Speedtest by Ookla include Fast.com, SpeedOf.Me, TestMy.net, Internet Health Test, and SpeedSmart. The main reason why Speedtest by Ookla has earned our recommendation has to do with the fact that it has servers all around the world, which ensures high accuracy of its tests.
The common name for the received radio signal power level in a wireless network is RSSI (Received Signal Strength Indicator). WiFi signal strength is typically measured in decibel milliwatts (dBm), a unit of the level that is used to indicate that a power ratio is expressed in decibels (dB) with reference to one milliwatt (mW).
When interpreting this unit, it’s important to keep in mind that the decibel scale is logarithmic and not linear. As such, 3 dB increase in level doubles signal strength, while 10 dB increase in level is equivalent to a 10-fold increase in power. To better understand what this means in practice, let’s take a look at the table below, which describes various levels of signal strength loss and how they affect network performance.
|Expected quality||Minimum signal strength for applications that require very reliable, timely delivery of data packets.|
|Expected quality||The maximum signal strength that is achievable under controlled conditions.|
|Required for||Voice over IP and real-time streaming video|
|Expected quality||Minimum signal strength for reliable packet delivery and tasks such as email.|
|Required for||Email and light web browsing|
|Expected quality||Minimum signal strength for basic connectivity, such as connecting to the network.|
|Required for||Connecting to the network|
|Expected quality||Extremely poor signal strength that makes any functionality, including connecting to the network, highly unlikely.|
Generally, signal strength between -55 dBm and -75 dBm is acceptable, depending on how close or far away from your wireless router you happen to be. If you’re in the same room as your wireless router and have trouble achieving good network performance, the chances are that there is a lot of environmental noise from various electronic devices and other wireless networks.
You can see just how much noise there is by measuring the Signal-to-Noise ratio (SNR), which is the difference in decibels between the received signal and the background noise level. For example, if you receive a signal of -70 dBm and the noise floor is measured at – 80 dBm, the SNR is 10 dB. Of course, you want the Signal-to-Noise ratio to be as high as possible so that it’s less likely for a signal to disappear in environmental noise.
Once you have completed your survey, there are three WiFi heatmap visualizations you will want to view:
Once you've identified areas of low Wi-Fi signal strength, you can take steps to correct it. Options include: moving an access point/router, adding a new access point, or installing Wi-Fi signal repeater or a WiFi extender.
If it's a high noise level that's the problem, you can take steps to reduce the noise by moving your access point, moving or shielding the interfering device, or switching from the 2.4 GHz band to the 5 GHz one. If the problem is high levels of interference, try changing channels to one with less interference. See these troubleshooting guides to learn more about signal level, noise level and channel interference.
To measure WiFi signal with the built-in utility on macOS perform the following:
Follow these steps to measure WiFi signal strength on Windows:
Alternatively you can use the WiFi indicator icon located in the taskbar on Windows and macOS to eyeball the strength of connection.
WiFi signal strength is expressed in dBm, which stands for decibels relative to a milliwatt.
When reading signal strength measurements, you need to know that dBm is expressed in negatives. -30 will be a higher level of signal than -80. Also remember that the decibel scale is logarithmic and not linear: 3 dB increase in level doubles signal strength, while 10 dB increase in level is equivalent to a 10-fold increase in power. In general if you get -70 or -65 dBm, you have a good signal.
Perform a WiFi survey and have a look at the following visualizations: