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FRITZ!Box reports "Wi-Fi transmission quality increased by reduced channel bandwidth"

The following message is displayed in the event log of the FRITZ!Box:

  • "Wi-Fi transmission quality increased by reduced channel bandwidth (2.4 GHz)"

Cause

  • In environments with many other 2.4 GHz Wi-Fi networks, the FRITZ!Box automatically reduces the channel bandwidth in the 2.4 GHz Wi-Fi network from 40 MHz to 20 MHz. By temporarily reducing the channel bandwidth, Wi-Fi connections in the 2.4 GHz Wi-Fi network are disturbed less and the user data rate of the connections is increased.

1 Selecting the best Wi-Fi channel

In the factory settings, the FRITZ!Box automatically checks the Wi-Fi environment and selects the Wi-Fi channel settings. However, with some disturbances it cannot determine the best Wi-Fi channel for all wireless devices. Therefore, select the Wi-Fi channel in the FRITZ!Box that is least affected by interference in the Wi-Fi environment:

  1. Click "Wi-Fi" ("Wireless") in the FRITZ!Box user interface.
  2. Click "Wi-Fi Channel" ("Radio Channel") in the "Wi-Fi" ("Wireless") menu.
  3. Click the link "Show disturbances to wireless network" in the section "Wi-Fi environment".
  4. Use the diagram to determine which channel in the lower frequency range is least affected by other Wi-Fi networks and interference.
  5. Enable the option "Adjust Wi-Fi channel settings" ("Adjust radio channel settings") in the section "Wi-Fi Channel Settings".
  6. From the drop-down list "Radio channel", select the Wi-Fi channel that was the least affected.
  7. Click "Apply" to save the settings.
  8. If the issue with your Wi-Fi connection still occurs, repeat steps 3 - 7 with a Wi-Fi channel in the middle and then with one in the higher frequency range. Then, use the Wi-Fi channel with the least interference.

    Important:The diagram of the Wi-Fi environment only reflects the current situation! The allocation of the frequency band can change significantly over the course of the day because many Wi-Fi networks are turned on when in use. Therefore, check several times to see which Wi-Fi channels are least affected by interference.