I was wondering what this sentence (Singapore to shut down 2G network) means:
I assume what it means but I want to know exactly what it means . I've never seen such structure of a sentence.
Don't feel too confused. It's not a sentence that can be fully understood without more world-knowledge than we have.
There's something called a "2G network" that Singapore controls in some way, whether because the city-state is the entity running it, or it's being run within Singapore's jurisdiction. And Singapore officials are going to shut it down for some reason we're not told. Whether the "2G" stands for "second-generation", "two gigabits per second", or something else is another thing we're not told, but presumably many Singaporeans are not so ignorant as we.
The structure is what's generally called "telegraphic" because messages sent by telegraph were charged for by the word (I think they still are, even though they're no longer sent by actual Morse-code telegraphy). So unnecessary words were omitted to reduce the total cost: "Singapore [intends] to shut down [the/its/...] 2G network"