FRITZ!Box 5490 Service - Knowledge Base

FRITZ!Box 5490 Service

Wireless 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 the wireless (WiFi) or DECT connections to the FRITZ!Box. This significantly reduces the range of the wireless or DECT connections.

1 USB 3.0 device is interfering with the wireless 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 only occurs rarely, and usually only during data transmission via USB and with poorly insulated USB 3.0 cables, which act like an antenna and amplify the radiation of the USB 3.0 device.

With radio connections, the radiation from such USB 3.0 devices reduces the range, data throughput, and quality of the connections. This affects wireless connections in the 2.4 GHz frequency band, but does not affect the 5 GHz frequency band.

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 homepage 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; instead, use a USB 3.0 extension cable to connect it to the FRITZ!Box.
  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.