Millimeter wave mobile communications for 5G cellular: It will work! was a revelation in 2013. Back then, most engineers believed that rain and atmosphere made mmWave spectrum would play only a modest role in mobile communications.
Looking back four years later, most of what Ted, Samini and team wrote in 2013 is confirmed. This article was triggered when I noticed then NYU grad student Mathew Samini was an author on 15 major papers in three years (below.) These included the propagation test data and a more accurate Statistical Channel Model, an essential for designing networks. (Abstract below.)
Verizon will soon turn on millimeter wave to (a very few) homes in 11 cities; the Koreans have major plans for the next 15 months. It does work. The NYU team performed tens of thousands of tests in Manhattan as well as in Brooklyn. Their data was convincing. Four years later, $billions are being spent to solve the remaining problems and start to connect hundreds of millions.
The 2013 IEEE paper noted, "Since signals cannot readily propagate through outdoor building materials, indoor networks will be isolated from outdoor networks and this suggests that data showers, repeaters, and access points may need to be installed for handoffs at entrances of commercial and residential buildings." In the event, most initial and early deployments will feature outdoor antennas.
They also predicted the importance of "heterogeneous networks with co-existing large macro, micro, and pico cells, and Wi-Fi access points. Low cost deployment will be realized by self-organizing features and repeaters/relays." While HetNets were the "next big thing" several years ago, but few were actually deployed back then, Over the last 12 months, HetNets again have become a hot topic, They work well now, with Verizon, Sprint, and T-Mobile deploying hundreds or more. Ibrahim Gedeon of Telus tells me small cells are currently the most important tool for capacity increases in his network.
The Brooklyn team did miss some trends. They expected, "At some point around 2020, wireless networks will face congestion." That now seems highly unlikely. In fact, wireless traffic growth has been falling. Speeds have doubled in the last few years on most networks. There is so much spare capacity Verizon, Sprint, and T-Mobile have gone "unlimited."
Now that smart phones are common, the traffic growth rate is down to 40%-45%, with Cisco confident it will continue to fall. The 100% traffic increases around 2009 were an artifact caused by smartphones first becoming available. The "unlimited" offerings may cause another spike, but even so the extensions of technologies in frequencies far lower than mmWave look to more than keep up.
Cisco's estimate is that U.S. traffic will grow 7X by 2020. The technology is improving even faster. Capacity can grow 8-15X in the next few years even without millimeter wave. A lack of traffic demand might persuade telcos to reduce capex. The biggest problem at most companies is they can't seel all hthe capacity they have.
Here are abstracts of some of the work.
Millimeter Wave Mobile Communications for 5G Cellular: It Will Work!
THEODORE S. RAPPAPORT, SHU SUN, RIMMA MAYZUS, HANG ZHAO, YANIV AZAR, KEVIN WANG, GEORGE N. WONG, JOCELYN K. SCHULZ, MATHEW SAMIMI, AND FELIX GUTIERREZ
This work was supported by Samsung DMC R&D Communications Research Team and Samsung Telecommunications America, LLC.
ABSTRACT The global bandwidth shortage facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks. There is, however, little knowledge about cellular mm-wave propagation in densely populated indoor and outdoor environments. Obtaining this information is vital for the design and operation of future fifth generation cellular networks that use the mm-wave spectrum. In this paper, we present the motivation for new mm-wave cellular systems, methodology, and hardware for measurements and offer a variety of measurement results that show 28 and 38 GHz frequencies can be used when employing steerable directional antennas at base stations and mobile devices.
Characterization of the 28 GHz Millimeter-Wave Dense Urban Channel for Future 5G Mobile Cellular
By Mathew K. Samimi and Theodore S. Rappaport
This technical report presents ultra-wideband statistical spatial and omnidirectional channel models for 28 GHz millimeter-wave cellular dense urban line-of-sight and non-line-of-sight environments, developed from wideband measurements in New York City that used synthesized timing from 3-D ray-tracing. An accurate 3GPP-like channel model has been developed, where model parameters are based on empirical distributions for time cluster and spatial (lobe) channel parameters. A statistical simulator capable of reproducing the joint temporal and spatial measured channel statistics is given here. A step-by-step procedure for generating channel coefficients is shown to validate measured statistics from 28 GHz field measurements, thus validating the statistical channel model.