As far as I'm aware Android does NOT support video call over 3G/native video call, some androids do in selected markets but that's up to the company to add this or not, again, Android does NOT support this natively. Hangouts/Gtalk has videocall it requires a data plan or wifi, there are other options on the playstore, skype, tango, yahoo, etc.
You contact Xperia care for more info http://www.sonymobile.com/gb/support/contact-us/
