Goodmorning everyone,
 I mean little about modem / router so I don't know if the product I am looking for exists. That's why I ask you.
 At home I have a Modem / router with Vodafone fiber that transmits via Wi-Fi to various devices ..
 I would now like a device that extends the wifi signal to which we can connect, and if there is a power outage or network problems that may have the possibility of inserting a SIM in order to pass the data connection automatically.  If all this had even a battery it would be great.
 Thank you all!