FCC Commissioner: Choosing the WRONG LANE (mmWave) in the race for 5G Spectrum
by Jessica Rosenworcel, Federal Communications Commission (FCC) in Wired.com – edited by Alan J Weissberger, IEEE ComSoc
Lost in the glowing 5G hype and headlines is the fact the United States is making choices that will leave rural America behind.
These choices will harm our global leadership in 5G and could create new challenges for the security of our networks.
The most important input in our new wireless world is spectrum, or the airwaves that are used to send and receive the radio signals that power wireless communications. For decades, slices of spectrum have been reserved for different uses, from television broadcasting to military radar. But today, demands on our airwaves have grown. So the Federal Communications Commission has been working to clear these airwaves of old uses and auction them so they can be re-purposed for new 5G service.
However, not all spectrum is created equal. The traditional sweet spot for wireless service has been in what we call low-band or mid-band spectrum. This is between 600 MHz and 3 GHz. For a long time, these airwaves were considered beachfront property because they send signals far. In other words, they cover wide areas but require little power to do so. This makes them especially attractive for service in rural areas, where technology that can reach more people with less infrastructure makes greater economic sense.
For 5G, however, the United States has focused on making high-band spectrum the core of its early 5G approach. These airwaves, known as “millimeter wave ,” are way, way up there—above 24 GHz. They have never been used in cellular networks before, and for good reason—they don’t send signals very far and are easily blocked by walls. That means they are very expensive to build out. On the flip side, these airwaves offer a lot more capacity, which translates into ultra-fast speeds.
Note 1. Millimeter wave spectrum is the band of spectrum between 30 GHz and 300 GHz. Wedged between microwave and infrared waves, this spectrum can be used for high-speed wireless communications as seen with the latest IEEE 802.11ad Wi-Fi standard (operating at 60 GHz). It is being considered by standards organization, the Federal Communications Commission and researchers as the way to bring “5G” into the future by allocating more bandwidth to deliver faster, higher-quality video, and multimedia content and services.
The United States is alone in this mission to make millimeter wave the core of its domestic 5G networks. The rest of the world is taking a different approach. Other nations vying for wireless leadership are not putting high-band airwaves front and center now. Instead, they are focusing on building 5G networks with mid-band spectrum, because it will support faster, cheaper, and more ubiquitous 5G deployment.
Take China, which allocated large swaths of mid-band spectrum for its carriers last year, clearing the way for deployment in a country that is also home to Huawei, the largest telecommunications equipment supplier worldwide. South Korea and Australia wrapped up an auction of key mid-band spectrum last year. At roughly the same time, Spain and Italy held their own auctions for mid-band airwaves. Austria did the same earlier this year. Switzerland, Germany, and Japan also auctioned a range of mid-band spectrum just a few months ago.
The United States, however, has made zero mid-band spectrum available at auction for the 5G economy. Moreover, it has zero mid-band auctions scheduled. This is a problem.
By ceding international leadership when it comes to developing 5G in the mid-band, we miss the benefits of scale and face higher costs and interoperability challenges. It also means less security as other nations’ technologies proliferate. Indeed, the most effective thing the United States can do in the short term to enhance the security of 5G equipment is make mid-band spectrum available, which will spur a broader market for more secure 5G equipment that will also benefit other countries that are pursuing mid-band deployments.
By auctioning only high-band spectrum, we also risk worsening the digital divide that already plagues so many rural communities in the United States. That’s because recent commercial launches of 5G service across the country are confirming what we already know—that commercializing millimeter wave will not be easy or cheap, given its propagation challenges. The network densification [2.] these airwaves require is substantial.
Note 2. Network densification will require hundreds of thousands of small cells which have to be mounted on public property in the U.S. The FCC issued a new ruling in September 2018 that set federal standards for small cell deployment regulation that aim to streamline the roll-out of 5G services across state and local governments. Similarly, state legislatures across the country have been considering bills that would create a uniform permitting and regulatory framework to support 5G network deployments. In general, a local government license will be required by the wireless telco that owns each small cell. Not all licenses will be granted as many city officials envision hordes of small cells to be a gigantic eyesore.
In fact, recent tests of newly launched commercial 5G networks in the United States are showing that millimeter wave signals are not traveling more than 350 feet, even when there are no major obstructions. They are also not penetrating walls or windows, making indoor coverage difficult.
This means that high-band 5G service is unlikely outside of the most populated urban areas. The sheer volume of antenna facilities needed make this service viable makes it too costly to deploy in rural areas. So if we want to serve everywhere—and not create communities of 5G haves and have-nots—we are going to need a mix of airwaves that provide both coverage and capacity. That means we need mid-band spectrum. For rural America to see competitive 5G in the near future, we cannot count on high-band spectrum to get the job done.
The heat-seeking headlines about 5G are hard to resist. But the reality on the ground needs attention, too. For the United States to have secure 5G service available to everyone, everywhere, we need to stop going at it alone with millimeter wave spectrum. We need to make it a priority to auction mid-band airwaves right now. The longer we wait, the further behind the United States will fall—and the less likely our rural communities will see the benefits of next generation of (5G) wireless technology.
THE WIRED GUIDE TO 5G
CTIA on 5G Spectrum: