Industry Voices—Entner: Flexible U.S. spectrum policy gets it right

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Unlike in the vast majority of other countries, the U.S. does not prescribe what wireless technology has to be used in conjunction with what spectrum. (Pixabay)
Roger Entner

Spectrum is the fuel on which wireless networks run. Mobile operators need a steady supply of new spectrum to satisfy the increasing demand from consumers and businesses alike.

The direct and indirect economic benefits created by the wireless industry's investment in high speed networks is well documented, as is the economic impact of the federal government’s incremental spectrum allocations to commercial network operators.

In just the last three years, the Federal Communications Commission has made 5 Gigahertz of millimeter wave (mmWave) spectrum available. That’s almost ten times more spectrum allocated to support high speed mobile broadband networks than has been allocated to support commercial mobile wireless in the last 30 years.

Not content to rest on its sizable allocation achievements, the FCC is beginning to now turn its attention to creating a path to access what is described as “mid band” spectrum, or “sub 6 GHz.” Currently, mobile network operators around the world are using 3.5 GHz to 4.2 GHz for 5G. In the U.S., the bulk of these frequencies were allocated years ago to satellite network operators; however, FCC’s Commissioner Mike O’Rielly is spearheading the FCC’s effort to make some of that spectrum available for terrestrial mobile operations.

In a whitepaper released to little fanfare in April, the U.S. Department of Defense Innovation Board acknowledged that there is 400 MHz of virtually unused spectrum in the 4 GHz band that could be made available for commercial wireless usage.

One of the key advantages the United States has in wireless is the policy of flexible use of spectrum. Unlike in the vast majority of other countries, the U.S. does not prescribe what wireless technology has to be used in conjunction with what spectrum.

Europe pursued a much different path with regard to their 3G spectrum and we all know the result. Despite being the global leader in 2G, Europe squandered this lead by deploying 3G very tepidly on the set-aside spectrum bands. Despite this recent past, most regulators in Europe mandate that in most European countries, 5G only can be deployed in the 3.5 GHz band, 4G only in the 900 MHz, 1800 MHz and 2.4 GHz bands.

In the U.S., mobile operators can be much more flexible and use whatever technology makes sense in the available bands. This is especially valuable in the transition phase from one generation of network technology to the next.

In 2020, a new technology called dynamic spectrum sharing will be deployed. This allows carriers to deploy 4G and 5G concurrently in the same frequency band and allocate bandwidth as needed. This is particularly useful in the traditional frequency bands that are currently heavily used by 4G devices.

Otherwise, a hard number of megahertz has to be given to a specific technology with the efficiency losses that come with it. When only 4G customers are using the spectrum, 100% goes to 4G, when 5G customers show up they get their share of the spectrum. This provides for the optimal allocation of spectrum at any given point in time and place.

Why is it important to have different frequency bands for 5G? There is an inherent trade-off between usability and speed. 5G in mmWave is very fast, with AT&T having shown up to 2 Gbps on their 5G network. But one of the challenges of deploying in mmWave bands is that the range of the signal is currently limited to 750 ft. to 1,500 ft and it has a hard time penetrating walls. In order for mmWave to work indoors, the carrier would have to install a transmitter in every room. This makes sense in an enterprise setting, but is not practical for homes.

Today, for all intents and purposed, mmWave is an outdoors solution. The combination of the raw number of MHz available, multiplied by the antenna size gives mmWave a huge speed advantage compared to low or mid-band spectrum, but at the expense of being able to penetrate walls. Thus, a successful operator needs a balanced portfolio of low, mid and high band spectrum to truly excel at a nationwide, 5G rollout.

And this is why the U.S. has provided the smartest path to 5G compared to its trading partners and global competitors. Only the U.S. has allocated spectrum for commercial mobile use across low and high bands, with work starting on making more mid-band available.

As long as the FCC refrains from trying to mandate technologies, and instead sticks to its knitting by allocating more spectrum, including mid-band, the U.S. consumers and businesses will benefit from mobile innovations made in the U.S.

Roger Entner is the founder and analyst at Recon Analytics. He received an honorary doctorate of science from Heriot-Watt University. Recon Analytics specializes in fact-based research and the analysis of disparate data sources to provide unprecedented insights into the world of telecommunications. Follow Roger on Twitter @rogerentner.

Industry Voices are opinion columns written by outside contributors—often industry experts or analysts—who are invited to the conversation by FierceWireless staff. They do not represent the opinions of FierceWireless.