Initially connectivity issues - then proper operation

Construction and installation went without problems. Originally I wanted to connect my UMTS modem (Huawei E180 USB stick) via the included USB docking station and even an extension cord to the wireless router. However, in this variant, the connection between the wireless router and UMTS modem was apparently not very stable. The stick indicated that a connection to the UMTS network is composed. Although the connection between the wireless router and UMTS modem could not be contacted, but was cut off after a certain period. Then helped only the UMTS modem off and reconnect. Even changes in the basic settings were not helpful.
Finally, I tried the UMTS modem directly, ie without connecting any cable to the wireless router. Since it works without any problems. For hours the connection is maintained. The unit now unfolds its full benefits.