Google's fabled mobile network launched today although it's a very limited launch. It's by invites rolling out slowly and you have to be a Nexus 6 user. The network is an MVNO through T-Mobile US and Sprint. It is all data (through calls as well). Google developed a system that seamlessly swaps between LTE between the networks and your wifi connection, whichever is faster. The real kicker is that they refund you back your money for the data you do not use. Obviously, this type of service isn't for people that use huge buckets of data.