Why 5G Millimeter Wave is Not Some Sort of "Mistake"

If you have ever looked at the National Telecommunications and Information Administration frequency allocation chart, you’ll immediately see that there is very little spectrum in the United States that remains unallocated.

An easier way of looking at where spectrum might be found is to look at where unused mobile spectrum exists. In this illustration, the orange color indicates unencumbered spectrum available for 5G, the green, purple and blue colors representing mobile spectrum already used by other mobile networks. In principle, all that 2G and 3G spectrum eventually can be reclaimed for 5G use.

But that will take some time.

source: Ericsson

So when critics claim that U.S. regulators, AT&T and Verizon have “made a mistake” by launching early 5G using millimeter wave assets, they miss the point.

There is very little spectrum left in the U.S. market in the 3.3 GHz to 4 GHz mid-band range that actually can be used to launch 5G, and AT&T and Verizon control very little of that resource.

The 3.5-GHz band, for example, will likely not be ready for commercial use until 2020, at the earliest. Most other countries have more unallocated spectrum in the 3.3 GHz to 4.2 GHz range.

source: Huawei

Other mobile operators have other options. T-Mobile US has new 600-MHz spectrum it can use. Sprint owns licenses for lots of 2.5 GHz spectrum. But AT&T and Verizon, to move early, had to rely on new millimeter wave assets.

There simply was not enough available spectrum, ready to go, in the other bands, if 5G was to launch early. That does not mean methods of repurposing, sharing and aggregating low-band and mid-band spectrum will be ignored. But neither AT&T nor Verizon could hope to launch early 5G, at scale, without relying on millimeter wave assets.

Also, if you look at what the International Telecommunications Union is working on, namely identifying millimeter wave bands for 5G and beyond, it is clear that on a global basis, millimeter wave spectrum will have to be used by 5G and all subsequent mobile generations. There simply is not enough spectrum in the low band and mid band, unless there is massive spectrum realloation over time.