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Wi-Fi or DECT connections are subject to interference when a USB 3.0 device is connected

A USB 3.0 device connected to the FRITZ!Box interferes with Wi-Fi or DECT connections to the FRITZ!Box. This significantly reduces the range of the Wi-Fi or DECT connections.

1 USB 3.0 device is interfering with the Wi-Fi connection

USB 3.0 devices with insufficient shielding can interfere with the radio connections of devices located very close to the USB 3.0 device or its USB 3.0 cable. Normally, such interference occurs only rarely, and mostly only during data transmission via USB and with poorly insulated USB 3.0 cables that act like antennas and amplify the radiation of the USB 3.0 device.

The range, data throughput, and quality of radio connections is reduced by the radiation from such USB 3.0 devices. This affects Wi-Fi connections in the 2.4 GHz Wi-Fi network, but does not affect the 5 GHz Wi-Fi network.

This effect applies to all wireless and DECT devices.

Note:You can find additional information on this topic in this article in PCMag UK and this White Paper from Intel on the home page of the USB Implementers Forum.


There are several ways to reduce the radiation affecting the FRITZ!Box. Start with the step that is easiest for you to implement:

  1. Increase the distance between the USB 3.0 device and the FRITZ!Box. If possible, do not connect the device directly to the FRITZ!Box; use a USB 3.0 extension cable instead.
  2. Change the position of the USB 3.0 device and its cable. For testing, also connect the device to the other USB port on the FRITZ!Box.
  3. Use a different USB 3.0 cable with better shielding.
  4. Change the USB mode to "Green Mode USB 2.0" under "Home Network > USB / Storage > USB Settings" in the FRITZ!Box user interface.