What is the Signal-to-Interference Ratio? [PRO]

The signal-to-interference ratio (SIR) is similar to the signal-to-noise ratio, but in this case the interference is specific to co-channel interference from other radio transmitters. The general consensus is that wireless devices will work reliably with the SIR ratio of  0dBm (decibels) or less. If you hover over the measurement markers on the map and look at the AP names on the left, you can see the exact ratios for each location.

The Signal-to-Interference visualization is one of the PRO visualizations available only to those that have upgraded to the PRO or Enterprise version of NetSpot. If your SIR levels are high, see Troubleshooting Overlapping Channels (SIR) for strategies to correct it. NetSpot PRO users also have access to Automated Troubleshooting to help identify interference issues.

Get started with NetSpot WiFi tool for macOS

There are several ways you can adjust this heatmap view:

  • Wi-Fi Network: Each Wi-Fi network detected can be mapped individually. Simply check the box next to the network(s) you wish to view on the left-hand side of the NetSpot window.
  • project gear icon

    Project Configuration icon

    Wi-Fi Channel: By clicking on the Project Configuration gear icon (on the bottom-left), you can also view the signal-to-interference ratio by channel.

  • View: By clicking on the Project Configuration gear icon and selecting Toggle, you can choose whether to show your path, sampling points, and AP titles on the map.
  • visualization gear iconAP Detection Proximity: By clicking the Visualization Configuration gear icon (next to the visualization drop-down menu), you can filter out weaker access points (APs) by adjusting the AP detection proximity slider. The default is -60dBm.
  • Min/Max Signal Level: By clicking the Visualization Configuration icon, the colors assigned to the SIR range can be adjusted by changing the Min Signal Level and Max Signal Level sliders. The default range is set to -0dBm (minimum) and -86dBm (maximum).
updated: April 23, 2018 author: Alex
Have more questions? Submit a request.