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Talking Cars: The FCC Holds a Key to Unlocking the Promise of Autonomous Vehicles



The dream behind autonomous vehicle systems is a world where people and goods are transported quickly and efficiently, without the accidents, pollution or visual clutter that are inevitable when humans control individual vehicles. The technologies needed to support autonomous vehicles are improving so quickly that this dream could soon become a reality. Regulators and lawmakers must immediately consider and confront the issue of digital roadway management.

One key to facilitating connected transportation and autonomous vehicles is efficient management of the spectrum upon which the vehicles will rely. Regulators around the world will have to adopt, implement and, on an ongoing basis, refine the rules for how this spectrum will be assigned, used and protected from interference.

Dedicated Short-Range or Cellular Vehicle-to-Everything Communication

In the United States, the Federal Communication Commission (FCC) in 1999 reserved the 5.9 GHz wireless spectrum band for transportation communication traffic using dedicated short-range communication (DSRC), which facilitates both vehicle-to-vehicle and vehicle-to-infrastructure communication. Since then, several automakers and a handful of state departments of transportation have outfitted vehicles and infrastructure with DSRC-based technologies. Not surprisingly, technology has improved significantly since then, leading to the development of various alternatives to DSRC, the most notable being cellular vehicle-to- everything (C-V2X) communication, a unified connectivity platform designed to offer vehicles low-latency vehicle-to-vehicle (V2V), vehicle-to-roadside infrastructure (V2I) and vehicle-to-pedestrian (V2P) communication.

C-V2X offers various advantages over DSRC. For example, C-V2X does not require a large-scale deployment of roadside units as it is designed to be compatible with forthcoming 5G mobile technology. Also, unlike DSRC, C-V2X uses two separate transmission modes: one for direct communications between vehicles, between vehicles and infrastructure and between vehicles and other road users, such as pedestrians, which ideally would leverage the dedicated 5.9 GHz wireless spectrum band; and the other for network communications, which would leverage traditional mobile service networks enabling vehicles to receive information about road conditions and traffic.

Ongoing Regulatory Examination

Under current FCC regulations, C-V2X systems cannot use the 5.9 GHz wireless spectrum band. But the agency is considering amending its rules to allow for alternatives to DSRC. In coordination with the Departments of Commerce and Transportation, the FCC has launched a three-phase research plan to evaluate options for opening the 5.9 GHz wireless spectrum band for non-DSRC uses. Throughout the study period, stakeholders and the public will be able to express their opinion as to whether the 5.9 GHz wireless spectrum band should remain allocated solely for DSRC, be preserved solely for additional automotive technologies like C-V2X, or repurposed, in part or in full, to meet increasing demands for additional spectrum to accommodate communications unrelated to automotive technologies.

Phase I of the plan was completed in October 2018. The FCC concluded that DSRC and non-licensed uses, such as Wi-Fi, are safely able the share the 5.9 GHz wireless spectrum band—a boon to C-V2X deployment, although its conclusion also opens up the possibility that the band’s repurposing could include non-automotive industries. After reviewing public comments on Phase I, the Commission, in coordination with the DOT and NTIA, will move onto Phases II and III, described in the public notice as follows:

  • Phase II: Basic field tests with a few vehicles at a DoT facility. The Phase II tests will determine whether the techniques to avoid interference that were evaluated in Phase I's lab tests are effective in the field.
  • Phase III: Tests in “real-world” scenarios, with many vehicles, more test devices, and at a suitable facility.

The timetable for completion of Phases II and III has not yet been announced, but that is not stopping key stakeholders from making their preferences known.

Differing Industry Opinions

To date, opinions on how the 5.9 GHz wireless spectrum band rules should be amended vary significantly. Several auto manufacturers, hardware developers and state departments of transportation that are heavily invested in DSRC are, not surprisingly, advocating for maintaining the status quo. Toyota has committed to deploying DSRC systems in vehicles sold in the United States starting in 2021 and GM deployed DSRC hardware in its 2017 Cadillac CTS. Toyota, GM and their supporters argue that DSRC technology is immediately available and has been validated as a means of reducing congestion and traffic fatalities. They also point out that a strong commitment to DSRC from the FCC would incentivize near-term investment by companies that are currently hesitant to invest in due to fear that it may be rendered obsolete by changes to the FCC’s regulations.

However, not all auto manufacturers are on the same page. Ford recently announced, at the 2019 Consumer Electronics Show, that it will adopt C-V2X as its preferred means of vehicle communication, aiming to integrate the technology by 2022. Additionally, the Regional Transportation Commission of Southern Nevada and City of Las Vegas announced a partnership with Qualcomm to outfit the city with C-V2X roadside units. Moreover, both “5GAA” a coalition of automakers, device manufacturers and telecom operators and Citizens Against Government Waste vigorously support a fast rollout of C-V2X. They argue that the current restrictions on the 5.9 GHz wireless spectrum stifle the growth and market viability of more effective 5G compatible technology.

Global Impact

Importantly, the U.S. is not the only country debating C-V2X vs. DSRC. The EU and China are both mulling over their automotive communications policies. At present, Europe is leaning towards DSRC while China seems to prefer C-V2X. For auto manufacturers, international regulatory disunion is disconcerting. In an industry dependent on international trade, manufacturers desperately want to avoid varying legal requirements and government preferences that could render their vehicle’s technology, useless. Once the U.S. concludes its three-phase examination, a domestic spectrum solution will come into focus.

While international consensus is from inevitable, it’s a battle worth fighting because clear decisions from major markets could influence stakeholders’ decisions in other regions. And if not, the history of wireless mobile services has demonstrated that technology will adapt to accommodate conflicting preferences by different regions.


Eric Tanenblatt is the Global Chair of Public Policy and Regulation at Dentons. Todd Daubert is the Chair of the Communications and Technology sectors at Dentons.