Verizon to begin testing 5G wireless network in 2016

Assuming peak performance, 5G throughput could hit up to 50 times that of LTE with lag under 10 milliseconds, Verizon said. The company is currently establishing 5G "sandboxes" at centers in Waltham, Mass. and San Francisco.

Verizon further claimed that while 5G is typically expected go live in the U.S. sometime after 2020, the carrier is "accelerating the expected rate of innovation." It did not suggest how much sooner a launch might happen.

In any event, 5G adoption may take some time. There is no ratified standard for the technology and even once one is established, hardware vendors will need to make compatible devices, and carriers like Verizon could take years to build out networks. In 2015 many American carriers are still working on LTE coverage, well after the first networks turned on.

In the meantime LTE still has some room to grow, since many networks and devices aren't anywhere near the peak of the technology. With LTE Advanced, downloads can theoretically be as fast as 1 gigabit per second.

The iPhone 6 and 6 Plus only support speeds up to 150 megabits per second. That could potentially change on Wednesday with the announcement of new iPhones.