Will you be able to use the new VoLTE service on your new iPhone 6?

VoLTE is coming to Apple iPhones for the first time with the new iPhone 6 and iPhone 6 Plus -- maybe not right away, but the service will roll out as time passes.

VoLTE stands for Voice over LTE, and it brings together voice and data together in the same spectrum. For Verizon subscribers it means that voice and data connections can finally work at the same time on an iPhone. It also increases the quality of voice service, providing something the marketing people call "HD Voice". For VoLTE to work between two mobile phones, both phones must be on the service. If one phones loses the VoLTE signal, the call automatically switches to the default older network.

VoLTE sounds great, but the rollout of these services is not going to happen instantly. Here's a thumbnail description of where each U.S. carrier currently stands:

• AT&T is putting VoLTE into the field, but so far it is only available in a few places -- parts of Minnesota, Wisconsin, Indiana and Illinois.

• Verizon is way ahead here, with VoLTE service quickly coming everywhere Verizon that has LTE capability.

• T-Mobile also plans a nationwide rollout, and they say they are working with Apple on getting everything up and running.

• Sprint has been publicly quiet about its plans, but persistent leaks say it will offer VoLTE sometime next year.

There's no benefit to VoLTE for current (pre-6) iPhones except one: as more phones switch to the VoLTE technology, the older networks will get less crowded, theoretically giving you fewer dropped calls.