Troubleshooting low signal level

Note: This visualization is available only for the Pro and Enterprise versions of NetSpot.

The signal level is the strength of your Wi-Fi signal. Signal levels lower than -40 dBm are of concern and lower than -70 dBm is considered critical. But what is truly important is your signal level in comparison to your noise level (see signal-to-noise ratio). A low signal level can be tolerated if the noise level is minimal.

If you are registering low signal levels in some areas of your Signal Level visualization, then your first step should be to deselect all of your APs on the left sidebar and then re-select them one by one. Try to narrow down which APs should be covering the area(s) of low signal strength.

• Optimize AP locations: You should minimize the number of obstructions between the AP and the low signal area. The material of the obstructions also plays an important role; for example, the attenuation factor of a brick wall far exceeds that of a cubicle wall or glass partition. If possible, avoid placing your AP near metal posts or filing cabinets, cement walls, or obvious sources of electrical interference.
• Add more APs: Sometimes repositioning APs does not provide the desired effect, and the best option becomes installing additional APs in the problem areas.
• Remove unnecessary APs: Generally it’s not recommended to install several APs close to each other in order to presumably improve Wi-Fi coverage, as this may actually lead to the opposite result. A signal overlap of 10-20% between APs is considered optimal.
• Stick to one manufacturer: Make sure you are using hardware from the same manufacturer. Compatibility is a tough issue, especially for wireless appliances.
• Use a different antenna: If an AP is installed in a corner or a place with limited visibility, a high-gain antenna (if your AP supports the use of such antennas) redirects the radio signal towards the desired direction, thereby increasing the signal level in some zones and decreasing it in the others.
• Increase output power: Some APs allow for the adjustment of transmission power. However, for most, the maximum power is already set as the default factory setting. If you are able to increase power, keep an eye on signal-to-interference values, as they may increase. Installing a Wi-Fi repeater or extender might be a good option.
• Stay up-to-date: It’s smart to always keep your APs’ firmware up-to-date. Manufacturers tend to improve their products quite frequently.
• Reconfigure WEP: If your network uses WEP security with multiple keys, reconfigure it to use only one.
• Use the latest security protocols: It is best to implement the latest security algorithms (WPA and WPA2). They provide more advanced features to configure the security of your wireless network in comparison to the outdated WEP protocol.
• Disable 40MHz in the 2.4 band: If your APs are using the 2.4GHz band and have the ability to use both the 20 MHz and 40 MHz channels, try turning off the 40 MHz. Macs, iOS devices and other modern hardware don’t support them and they can cause increased instability. Disabling this mode might also improve noise values.
• Use antennas with a low amplification factor: Make sure APs are configured to use diversity reception. All-directional antennas with low amplification factors decrease the probability of multi-beam signal propagation if they are placed at a non-standard height (such as in exhibition halls). Low amplification also results in each AP covering a smaller area, meaning less users will be connecting to it simultaneously. This minimizes the traffic load on each AP, and also lowers interference in the network.