FRITZ!Box 6890 LTE Service - Knowledge Base

FRITZ!Box 6890 LTE Service
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Mobile connection drops frequently

The mobile connection between your FRITZ!Box and your mobile network operator drops frequently (several times a day). When this occurs, the "Power" LED on the FRITZ!Box flashes and stays lit as soon as the internet connection has been reestablished. The following error message is displayed in the event log of the FRITZ!Box:

"LTE no longer responding"


  • The stability of the mobile connection depends on factors such as the distance from the mobile station and the shielding effect of the walls of your own house. It can also be affected if your mobile network operator is experiencing technical difficulties.

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

Simply proceed as described below. After each measure, check whether the problem is solved.

1 Checking the event log of the FRITZ!Box

  1. Click "System" in the FRITZ!Box user interface.
  2. Click "Event Log" in the "System" menu.
  3. Check whether there are any events that occurred before the error did, or whether only events that occurred after the error are shown.
  4. If events that took place before the error occurred are also shown, continue with the next section:

2 Using a different modem version

The software version for the FRITZ!Box's integrated mobile broadband modem undergoes constant development with each FRITZ!OS to ensure that it can establish optimal mobile connections under all circumstances. However, in rare cases the FRITZ!Box may only be able to establish a mobile connection with certain versions. Therefore, test the current and the previous modem version:

Using the latest FRITZ!OS

The modem version is part of FRITZ!OS. Make sure that the FRITZ!Box is using the latest FRITZ!OS and therefore the latest modem version:

  1. Install the latest FRITZ!OS on the FRITZ!Box.

Using the previous modem version

If the problem occurs with the latest modem version (for example after updating FRITZ!OS), test the modem version of the previous FRITZ!OS:

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "LTE Information" in the "Internet" menu.
  3. Click on the "Reception" tab.
  4. Enable the option "Use previous software version for the integrated mobile communications modem".
  5. Click "Apply setting" to save the settings.

Now the FRITZ!Box enables the previous modem version and reinitializes the modem. Afterwards, the FRITZ!Box attempts to establish a mobile connection again.

3 Selecting the type of mobile communication

Depending on your mobile network operator and contract, if there are several radio cells at your location, you may need to manually select the desired type of mobile communication in the FRITZ!Box:

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "Account Information" in the "Internet" menu.
  3. Click on the "Internet Connection" tab and then on the "Mobile" tab.
  4. In the section "Type of mobile communication", enable the option "Manual" and disable the option "UMTS".
  5. Click "Apply" to save the settings.
  6. If you are now no longer able to connect to the mobile network, re-enable the option "UMTS" and click "Apply".

4 Checking the LTE antennas

Mistakes made when connecting the LTE antennas can often be overlooked. Therefore, check whether the LTE antennas were correctly connected to your FRITZ!Box:

  1. Check the pin in the connector of both LTE antennas. If the pin is bent or has broken off, there can be no contact between the LTE antenna and the FRITZ!Box.
  2. Make sure that both of the LTE antennas included in the package are correctly screwed onto the sockets labeled "LTE" on the FRITZ!Box.
  3. Swap the LTE antennas connected to the two LTE antenna sockets on the FRITZ!Box. Check whether the FRITZ!Box can then establish an LTE connection.
  4. If you are using an outdoor LTE antenna, check whether you can establish an LTE connection if you use a different outdoor LTE antenna or a different LTE antenna cable. If you can establish a connection then, either the outdoor antenna or antenna cable is not suitable or is defective.

    Note:If you are using the FRITZ!Box in the indoor coverage area of your LTE provider, test whether you can establish an LTE connection if you use the original LTE antennas included in the package.

5 Finding the ideal location for the FRITZ!Box

You can use the alignment aid to find the ideal location for the FRITZ!Box and the best position for the mobile broadband antennas:

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "LTE Information" in the "Internet" menu.
  3. Click on the "Reception" tab.
  4. Click the "Start Alignment Aid" button.
    • Now the current signal strength of the antennas is displayed by the LEDs on the FRITZ!Box (in five levels) and in the user interface.
  5. Select a location for the FRITZ!Box where the signal strength is as high as possible. When doing so, note the following:
    1. Do not set up the FRITZ!Box in the corner of a room.
    2. Place the FRITZ!Box as close to an outside wall as possible. If you know where your provider's radio cell is located, position the FRITZ!Box by the wall facing the radio cell.
    3. Place the FRITZ!Box so that it is as unobstructed as possible, i.e. not directly in back of or under an obstacle such as pieces of furniture or a heater.

6 Connecting an outdoor LTE antenna

If you are using the FRITZ!Box in an area located on the edge of the LTE radio coverage area (outdoor coverage area), using LTE antennas in your house may not be sufficient to establish an LTE connection. In this case, increase the transmission and reception power of the FRITZ!Box by using an outdoor LTE antenna on your roof or balcony, for example:

Note:Your LTE provider can tell you whether you are using the FRITZ!Box in their indoor or outdoor coverage area.