FRITZ!Box 4040 Service - Knowledge Base
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 possible with 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)"
- The FRITZ!Box recognizes when the wireless channels it uses in the 2.4 GHz frequency band are subject to 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 defined by 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.
1 Enabling or refreshing the auto channel
When the auto channel is enabled, the FRITZ!Box checks the wireless environment and automatically selects the most suitable wireless channel settings. The allocation of the frequency bands can change significantly over the course of the day, though. The FRITZ!Box does not refresh the auto channel as long as wireless devices are still connected with it. However, you can manually update the auto channel at any time:
- Click "Wireless" ("WLAN") in the FRITZ!Box user interface.
- Click "Radio Channel" in the "Wireless" ("WLAN") menu.
- Enable the option "Set radio channel settings automatically (recommended)".
- Click "Apply" to save the settings.
Note:All wireless connections to the FRITZ!Box are cleared and then automatically re-established when you enable or refresh the auto channel.
- Click the "Refresh Auto Channel" button.
Wireless connections to the FRITZ!Box are now 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, then this is because of the heavy use by wireless networks in the vicinity.