What's this prominience in the B737? I have recovered some spotting pictures that I made long ago and I came to realize an upper prominence in the fuselage of this Norwegian Boeing 737. I don't remember to have seen it in other 737s.

Does anyone know what is it and its purpose?
It's a SATCOM (Satellite COMmunication) antenna. It has several purposes, one of them is internet connection for the passengers.

There are different types and configurations. On some aircraft the antenna is in the front, on some it's in the back, some have two.

(image from http://www.b737.org.uk/latest-2016-04-06.htm)