Nearly free, call-and-install, 1.5-megabit-per-second bandwidth to home offices and handhelds would be radical.

FORBES: Digital Rules

So whilst the "official" definition of 4G talks about one gigabit per second (Gbps) speeds, the marketing departments of mobile operators call 4G anything over 30Mbps or so.

BBC: Viewpoint: What 4G means for you and your phone