Just a Standard Blog
It’s hard to imagine (or remember) a world without Wi-Fi. Wireless communications — cellular, Wi-Fi, Bluetooth — are an integral part of our everyday lives. Those services require a radio-frequency spectrum to function.
Radio waves are a form of invisible light. It’s part of the electromagnetic spectrum, which also includes microwaves, infrared, visible light, X-rays, ultraviolet radiation and gamma rays. The radio-frequency spectrum is a spectrum of invisible light, often used in wireless communications.
Think of the spectrum as being like an invisible highway where our wireless communication travels. There is a limited amount of space. Most of the lanes have already been allocated for specific uses, such as commercial or emergency communications, weather satellites, or military systems. This leaves less space to meet the growing public demands for wireless communications. The traffic demands on that proverbial highway increase every year.
What would we do if the world ran out of this spectrum? Would there be enough data to meet everyone’s needs for streaming and texting? It’s something NIST and our partners are working to prevent through spectrum sharing.
The radio-frequency spectrum is divided into bands of different frequencies. Like different lanes in the road, some of these bands allow data to travel faster or for longer distances. Some are reserved for specific users. You don’t want military communications stuck in digital traffic with the latest social media memes.
The spectrum has been divided up over the decades. As our technology expanded, telecommunications companies, governments and scientific research agencies (such as NASA) were given or bought bands for their own use.
Why can’t we just make more radio-frequency lanes? We don’t have more radio-frequency spectrum to develop. It’s a natural resource, and we have to share it.
In 2017, the federal government and industry proposed a new approach to sharing spectrum. The Citizens Broadband Radio Service (CBRS) launched in 2020. The CBRS is a band of spectrum that was previously reserved for Navy aircraft carriers, particularly for radar and aircraft communications. This is critical to every mission. However, since it’s not used all the time on land, it’s an ideal spectrum to share with others.
It’s not just opening a new lane or a new band on the radio-frequency highway. This is like opening an entire new type of interstate system across the country. Telecom companies, the military and the public can use it. This is the first time that all three can use this digital roadway together.
CBRS is the largest shared spectrum ecosystem in the world. It has a unique three-tier approach.
You can think of it as a highway with carpool lanes. But these aren’t just any carpool lanes. These are high-tech lanes with an automated system that detects when the lane (spectrum) is empty. The system opens the lane to single drivers (the public) when it’s not in use. It keeps others off the road when the priority cars (the Navy) need to use the lane.
Your device may have already connected to a CBRS network without you knowing it. Even if you’re nowhere near Navy facilities, equipment or ships, the spectrum may be available where you are, if the Navy is not using it.
CBRS networks have been popping up around the country to support localized, high-data usage areas, such as universities and sports stadiums. In facilities with these networks, it’s used for things like concession stand sales and coaching staff communications or supporting video streaming for virtual classes. This allows other frequencies to remain open for fans to use their own devices with plenty of bandwidth. Otherwise, networks may be overwhelmed with traffic from so many users concentrated in a small area.
Since the need for wireless communication keeps growing, we need to make sure we can continue to share this spectrum. If the priority users like the Navy have a problem, or if commercial users can’t use it, then sharing this spectrum won’t work. That requires unbiased, reliable and accurate data.
That’s where the National Advanced Spectrum and Communications Test Network (NASCTN) comes in. NASCTN is a multi-agency partnership, hosted at NIST. It provides testing, modeling and analysis of spectrum-sharing technologies. The NASCTN team includes staff from NIST, the Department of Defense, NASA, the National Oceanic and Atmospheric Administration, the National Science Foundation, and the National Telecommunications and Information Administration.
CBRS needs measurement, and we know how to measure.
Before joining NASCTN, I spent 15 years working for the Navy in electronic warfare. I made sure multiple military systems (such as radars and radios) could operate together with minimal interference. I am working to expand access to all things in the radio frequency — military systems, cellular networks, Wi-Fi, medical devices, weather satellites and more.
Our team is leading the five-year effort that will provide data-driven insight into the CBRS sharing ecosystem’s effectiveness and track changes in the spectrum environment over time.
It is exciting to be part of a new spectrum ecosystem, measuring how it changes and evolves from its first launch. The rules and the technology around sharing the CBRS are even being updated as we take measurements because the information changes so quickly.
In October 2022, we deployed our first set of prototype sensors to sites in Norfolk, Virginia, and Hampton, Virginia. These sensors are measuring how the spectrum-sharing process can remove users quickly when the Navy needs it. If a public user is removed during a time that the Navy needs the spectrum, they may be shifted to another band on the spectrum, or a different lane in the proverbial highway of data.
Our data will help everyone who uses the spectrum determine if spectrum sharing will continue to work and how to make it most effective for all users.
We’re building and modifying this new interstate while we’re driving on it — without slowing down traffic. It’s not an easy task.
If this effort is successful, we’ll continue to expand the data available in places where data may be at a premium, like packed stadiums. But that’s just the beginning of the possibilities.
Businesses may use this spectrum for uses like:
Whatever technical innovations in the future may require more data, NIST and our partners will work to test spectrum sharing to ensure it’s available for all who need to stay connected.
Great job, Melissa. The work NASCTN does is crucial to the ever-growing demands of our interconnected world.