Questions about TP-Link TL-MR100

Is it possible to replace the antennas of this device with others (external antennas)? Which connection does the antenna have?

Good day I received the router yesterday and activated the SIM card, which was also confirmed. Now the device is not establishing an Internet connection. Switching it off several times, reinserting the SIM card or pressing reset have not changed anything. Is there anything that can be done? If so, what? If not, I would like to return the device!

This device works fine. However, my internet connection is very slow. If I use my phone instead as a hotspot for the same network it is much faster. I have tried changing the position of the router, including putting it outside of the window. But it does not change significantly. Is it the 3G antenna of the router that is not good?

Can the unit be mounted on the wall?

Nue WEP ist falsch. Produkt unterstütz: · Wireless Security: 64/128-bit WEP, WPA/WPA2, WPA-PSK/WPA2-PSK encryptions

Is it possible to use the router with a nano-sim and adapter. With the Fritzbox, this is not recommended because it could get stuck.