Ted Rappaport of NYU, the world's foremost mmWave researcher, disagrees with my guess that mmWave 5G will be modest until 2021-2023. My opinion is backed up by opinions from several carriers and an estimate from Ovum that fewer than 1% of lines will be millimeter wave in 2021. Ted's opinion is shared by Verizon CEO Lowell McAdam, who will deploy in Boston and probably San Francisco as soon as Verizon can get the equipment. That should be late 2017 or early 2018. Nokia and Ericsson have hundreds of engineers working on 5G mmWave.
I will be delighted to be proven wrong and see more rapid progress. Since my comment, Rappaport and team have published a seminal paper, Millimeter Wave Wireless Communications: New Results for Rural Connectivity (Abstract below.) They were able to detect a 73 GHz signal 11 kilometers away from their transmitter, a carefully aligned antenna 110 meters above average terrain. (Pictured.) They used 1 watt of transmitter power, levels similar to today's mobile phones.
Ted believes, "to a first approximation, the range won't be different in clear weather for mmwave versus today's cellular as long as the physical size of antennas are the same at both frequencies." On a clear day, with line of sight, it's clearly possible to measure millimeter waves far beyond the 100-300 meters most urban deployments expect. I had a chance to discuss Ted's paper with NTT engineers, who were impressed.
Ted is a world-class engineer; I'm a tech reporter who sounds smart because I listen to people like Ted. I'm obviously not qualified to judge which excellent engineers have this one right. Here's Ted's note:
Many people continue to propagate the incorrect myth that mmwave is severely limited in distance. This is not accurate. The fact is that the distances at mmwave will only be limited by rain and fog, not by the nature of mmwave. This is because the "lossiness" of mmwave, compared to lower frequencies, only occurs in the first meter of propagating distance, but this "higher loss" is cancelled out by keeping the antennas the same physical size at all frequencies.
ABSTRACT Millimeter Wave Wireless Communications: New Results for Rural Connectivity [Editor's note: most of the article is about the model, not the testing.]
This paper shows the remarkable distances that can be achieved using millimeter wave communications, and presents a new rural macrocell (RMa) path loss model for millimeter wave frequencies, based on measurements at 73 GHz in rural Virginia. Path loss models are needed to es- timate signal coverage and interference for wireless network design, yet little is known about rural propagation at millime- ter waves. This work identifies problems with the RMa model used by the 3rd Generation Partnership Project (3GPP) TR 38.900 Release 14, and offers a close-in (CI) reference distance model that has improved accuracy, fewer parameters, and better stability as compared with the existing 3GPP RMa path loss model. The measurements and models presented here are the first to validate rural millimeter wave path loss models.