You can have mobile-phone broadband, but it's expensive and a bit rubbish. Apparently the new version is better, but it's still expensive. Sattelite also is outrageously expensive.
Otherwise you do need a cable or BT line, but I guess whether or not you actually use it to make calls is your business - fuzzywuzzy, do people really do that? Surely you have to pay the line renatl anyway?