FRITZ!Box 4020 Service - Knowledge Base
FRITZ!Box reports "Wireless LAN transmission quality increased by reduced channel bandwidth"
Wireless connections (WiFi) according to wireless standard 802.11n are established with a throughput that is considerably less than 450 Mbit/s. The following error 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 that the wireless channels it uses in the 2.4 GHz frequency band are subject to heavy use by other wireless networks. In order to still guarantee stable wireless connections, the FRITZ!Box automatically reduces the channel bandwidth to 20 MHz. Although the wireless devices display a lower throughput as a result, the user throughput is higher because it is not affected by retransmissions. This FRITZ!Box function ("wireless coexistence") complies with wireless standard IEEE 802.11n.
1 Enabling or refreshing the auto channel
If the auto channel is enabled, the FRITZ!Box checks the wireless environment and automatically selects the optimum wireless channel settings. However, the allocation of the frequency bands can change significantly over the course of the day. The FRITZ!Box does not refresh the auto channel as long as wireless devices are still connected with it. You can therefore manually refresh the auto channel at any time:
Note:All wireless connections to the FRITZ!Box are cleared and then automatically re-established when you enable or refresh the auto channel.
- 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.
- Click the "Refresh Auto Channel" button.
The FRITZ!Box now establishes wireless connections with the highest possible throughput.
Note:If the error 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.