FRITZ!Box 4040 Service - Knowledge Base

FRITZ!Box 4040 Service

FRITZ!Box reports "Wireless LAN transmission quality increased by reduced channel bandwidth"

The speed of the wireless connection (WiFi) to the FRITZ!Box displayed by wireless devices such as computers, smartphones, or tablets, is significantly lower than the data rate allowed by the wireless standard 802.11n. The following message is displayed in the event log of the FRITZ!Box:

  • "Wireless LAN transmission quality increased by reduced channel bandwidth (2.4 GHz)"

Cause

  • The FRITZ!Box recognizes when the wireless channels it uses in the 2.4 GHz frequency band are in heavy use by other wireless networks. To ensure stable wireless connections, it automatically reduces the channel bandwidth from 40 MHz to 20 MHz. This FRITZ!Box behavior is conform to wireless coexistence, which is part of the wireless standard 802.11n. Although wireless devices then display a lower data rate, the user data rate is increased because there is less interference and the wireless connection is no longer affected by constant retransmissions.

Note:All instructions on configuration and settings given in this guide refer to the latest FRITZ!OS for the FRITZ!Box.

1 Automatically configuring wireless channel settings

Configure the following settings so that the FRITZ!Box checks the wireless environment on a regular basis and automatically selects the best wireless channel settings.

  1. Click "Wireless" ("WLAN") in the FRITZ!Box user interface.
  2. Click "Radio Channel" in the "Wireless" ("WLAN") menu.
  3. Enable the option "Set radio channel settings automatically (recommended)".
  4. Click "Apply" to save the settings. Now wireless connections to the FRITZ!Box are briefly cleared and then automatically reestablished.

Now wireless connections to the FRITZ!Box are established with the maximum possible data rate.

Note:If the message "Wireless LAN transmission quality increased by reduced channel bandwidth [...]" is still displayed in the event log of the FRITZ!Box, this is due to the heavy use by wireless networks in the vicinity.