Communications technologies, including radio, mobile telephones, and Wi-Fi, transmit over radio waves called spectrum. Similar services – broadcast television and mobile voice and broadband services, for example – are allocated ranges of frequencies, called bands, to prevent interference and allow for efficient use. Low-band spectrum (under 1 GHz) allows for better coverage over large areas and inside buildings, providing better coverage, while higher bands provide greater capacity. Low-band spectrum is significantly more scarce than higher-band frequencies.
In the United States, spectrum is “licensed” or “unlicensed,” and is managed by the Federal Communications Commission. Licensed spectrum is typically used for commercial or government purposes, and can only be used by the entity that holds the license. Unlicensed spectrum was first established by the FCC in 1985, and allows the public to freely use services without a license, such as Wi-Fi networks, baby monitors, and cordless telephones.
There has been a substantial push in recent years to find more spectrum for unlicensed uses and to promote efficient uses of all spectrum. Unlicensed spectrum greatly benefits competition in wireless broadband, innovation in technology that relies on short-distance radio communication, and even the needs of first-responders, like firefighters and ambulances, who rely on immediate radio communication to save lives. Additional unlicensed spectrum could come from several sources, particularly TV white spaces, which are the unused areas of spectrum between TV channels, and underutilized bands, including some where government agency operations are located.
The FCC completed a first-of-its-kind broadcast incentive auction in April 2017, which allowed telecommunications providers to bid on spectrum licenses owned by broadcasters. Broadcasters voluntarily participated to relinquish airwaves for mobile use in exchange for a portion of the winning bids. The auction freed up 84 MHz of spectrum nationwide, including 14 MHz for use by wireless microphones and unlicensed technologies.
Additionally, mobile broadband carriers are now bringing forward a new protocol to route traffic that will make use of unlicensed spectrum to take some of the burden off of the licensed spectrum they use to transmit phone calls, videos, and other Internet traffic. The new protocol is called LTE-U (adding the “U” to the 4G service called “LTE” because it adds unlicensed spectrum to the bands wireless carriers can use to serve their paid subscribers). While LTE-U holds great potential, there are concerns within the unlicensed spectrum community that the protocols LTE-U uses might slow down or degrade other uses of unlicensed spectrum, including Wi-Fi connectivity. The FCC’s obligations to the public interest requires it account for the impact on consumer uses and benefits of Wi-Fi over unlicensed spectrum before approving the use of LTE-U.
DSRC and the 5.9GHz Band
In 1999, the Federal Communications Commission authorized an allocation of 75MHz of the 5.9GHz spectrum band for “Dedicated Short-Range Communication” (DSRC). Seventeen years later, the National Highway Traffic and Safety Administration (NHTSA) intends to require all new model cars have “DSRC units” installed, which will enable vehicle-to-vehicle communication. However, there are several concerns the FCC needs to address first, including cybersecurity, privacy, safety, and spectrum sharing. Learn more on our “DSRC: The Privacy and Security of Vehicle-to-Vehicle Communication” page, here.
What PK Is Doing…
PK is working to ensure that the public airwaves serve the public. This means working with carriers to improve wireless broadband services, and advocating for the FCC to make spectrum available for first-responders and other unlicensed uses.
PK is working to ensure spectrum is not hoarded by just a few companies, but is distributed in a way that encourages competition.
Public Knowledge is working to ensure privacy and cybersecurity concerns are addressed with the implementation of DSRC units in vehicles.
To learn more check out the following:
We reported on two Congressional hearings last year that focused on the importance of unlicensed spectrum.
PK's John Bergmayer wrote a blog post about our position on LTE-U, entitiled “A Shared Resource Like Unlicensed Spectrum Needs Technologies That Know How to Share.“
We produced an informational video about how spectrum affects individuals:
PK produced two white papers on spectrum reform: Breaking the Logjam: Creating Sustainable Spectrum Access Through Federal Secondary Markets and Breaking the Logjam: Some Modest Proposals for Enhancing Transparency, Efficiency and Innovation in Public Spectrum Management.
We have an animated video, podcast episode, and more explaining DSRC, which you can view here.
Here are the PK experts on this issue: