Some places will only be 2-5X. With hundreds and soon thousands of systems in Japan and China, there's no doubt the technology works. SoftBank and China Mobile were first in the world to deploy, Now, Sprint, AT&T, and Verizon are discussing when, not whether. Since Sprint is owned by SoftBank, it was easy to predict they would join in. Mike Dano at Fierce had this story a month ago; now Ottendorfer has filled in the details.
"Massive MIMO – massive volumes of input and output streams – might sound like geek talk – it’s really just the ability with massive computing power to add massive numbers of antennas elements in the antennas on our cell sites. And 3D beamforming supported by Massive MIMO is simply more cell signals moving in both horizontal and vertical directions."
Gig LTE & Massive MIMO will raise capacity on U.S. networks at least 4X and more likely 7-15X in the next few years.