With all the current excitement around emerging high-tech autonomous vehicles and internet of things (IoT) devices, it may surprise some observers that around 20 years ago the Federal Communications Commission (FCC), at Congress’s direction, was already taking some important steps with respect to these technologies.  Most notably, the FCC set aside the 5.9 GHz band, which is a swath of highly-valued mid-band spectrum, for vehicle related communications and transportation safety features.  At that time, the FCC pursued Dedicated Short Range Communications (DSRC) as the standard to develop critical safety services, but over time, similar technologies outside of the 5.9 GHz band have developed.  More recently, a number of manufacturers and developers have been focused on a new technology called Cellular Vehicle to Everything (C-V2X), which proponents argue should be the standard going forward.

The FCC has decided to weigh in on the issues in the 5.9 GHz band in a draft notice of proposed rulemaking (NPRM) to be voted on at its December 12 Commission Open Meeting.  The 5.9 GHz band has been a political issue subject to disagreements among the FCC, Department of Transportation, and members of Congress on both sides of the aisle, regarding the best path forward, which technologies should be pursued, and whether there is enough spectrum that can safely be shared among different use cases. 

To provide a roadmap to the FCC’s draft NPRM, among other measures, it proposes to take the following three major steps, each of which we discuss further below:

  • Repurposing the lower 45 MHz of the band for unlicensed operations (such as Wi-Fi routers and connected devices);
  • Dedicating 20 MHz of spectrum to C-V2X operations; and
  • Seeking comment on whether to retain the final 10 MHz of the band for DSRC, or to also dedicate this last bit to C-V2X.

Repurposing Spectrum for Unlicensed Uses.

Unlicensed spectrum is important for the expansion of Wi-Fi and the connectivity of IoT devices to the internet.  And as the demand for Wi-Fi and connected devices increases, so too does the need for additional spectrum dedicated for these purposes.  In fact, the FCC explains in the draft NPRM that “[i]ndustry studies project that the U.S. will need between 788 megahertz and 1.6 gigahertz of new mid-band spectrum by 2025 to accommodate the growing demand for Wi-Fi.”  If the proposal is adopted, this additional 45 MHz of spectrum would be adjacent to another swath of unlicensed spectrum, and this increased contiguous block is among the reasons the FCC sees this as a good use of the spectrum.

20 MHz for C-V2X Operations.

Chairman Pai, in remarks made in advance of releasing the draft NPRM explained that “one promising new technology that is gaining momentum in the automotive industry is C-V2X. C-V2X would use standard cellular protocols to provide direct communications between vehicles, and, as the name suggests, everything—including other vehicles on the road, infrastructure (like light poles), cyclists (like me), pedestrians, and road workers.”

Some parties assert that C-V2X will be compatible with a wider range of use cases and even more advanced applications that will rely on higher bandwidth networks and faster speeds.

10 MHz for DSRC or C-V2X Operations.

Finally, the draft NPRM seeks comment on how to allocate the final 10 MHz of spectrum in the band.  The NPRM leaves open the possibility of retaining this spectrum for use with DSRC operations.  In the Chairman’s remarks, he noted, for example, that Japan “has a single 10-megahertz channel for DSRC that is actively used for collision avoidance around intersections.”  The FCC’s draft asks for commenters to help explain the best use for this in-demand spectrum.

The 5.9 GHz NPRM is another in a line of proceedings in which the FCC seeks to reallocate valuable spectrum for new uses.  The spectrum made available through these proceedings may be used to support the deployment of IoT devices, autonomous vehicles, and other new technologies that must rely on spectrum to function.