According to a new Market Data forecasts from ABI Research (www.abiresearch.com), it will take more than five years for 5G to reach 100 million subscriber mark — two years longer than 4G.

4G subscriber growth was much faster than with previous generations, fueled by the capabilities of increasingly powerful smartphones and the availability of 4G devices. 5G subscriber growth will likely be a bit more muted at first due to the increased complexity of 5G cells and networks, but will pick up in 2023.

"There are a number of commonalities between countries that are early builders of 5G networks. They have a large population, of which a large percentage is living in urban areas. They also have many companies pushing the envelope with IoT strategies. These countries will drive 5G subscriber volumes" says Research Director Philip Solis. "These are the United States, China, Japan, South Korea, and the United Kingdom in order of 5G subscribers in 2025."

It is also important to understand the nuances around 5G to recognize where it is headed. 5G will be a spectrum of evolution to revolution—it will be an evolution of the way the core network and network topology is transforming now, but it will be clearly delineated as a fifth generation mobile air interface on which the mobile network of the 2020’s and 2030’s will be built, adds Solis.

5G will encompass spatial division as the foundation of the air interface, leveraging techniques like massive MIMO—achievable in devices because of the high frequency of spectrum that will be used—and 3D beamforming to form narrow beams that divide the space around a 5G basestation. Client devices will have links to multiple cells simultaneously for robust connectivity.

Spectrum will be used flexibly and shift as needed between access and fronthaul and backhaul. The waveform and modulation scheme are the least clear aspects of 5G currently.

A 5G network will be a network of small cells and will be practical in urban and industrialized environments for the population density and the reflections in urban canyons; however, expect a scaled down version of 5G to use existing spectrum for macrocells as well in the longer term. One potentially problematic issue, however, will be regulatory issues concerning concentrated RF beams in centimeter and millimeter wave spectrum, according to ABI Research.