Loosing mobile data connection

[Keshan]

my mobile data doesnt work... i already changed my sim but it again happened.. adn i try it with charging full of my battery but it doesn't work so what should I do?

[_alexdon_]

Have you downloaded internet settings?Settings-xperia-download internet settings.

[Alexander1]

You can also try to add them manually under settings > more > mobile network > access point name > menu button > new APN. 

Ask your network provider for the data to fill in.