INSIGHT: Elaine Chao Needs to Better Prioritize DOT’s Spectrum Fights

Sept. 25, 2019, 8:01 AM

As Americans demand more wireless services, the radio spectrum that supports wireless communications is being pushed to its capacity limits. For this reason, it’s been a long-standing pillar of U.S. telecom policy to identify spectrum that can be repurposed to satisfy modern needs.

Such repurposings often require taking from one to give to another, which in turn leads to some nasty disputes—often involving government users. As former NTIA Administrator David Redl observed, “the era of easy spectrum decisions is over.”

Among many on-going examples, we can look at the current dispute between the Department of Transportation and the Federal Communications Commission over the latter’s attempt to repurpose 75 MHz of prime mid-band spectrum in the 5.9 GHz band for unlicensed use.

In 1999, the FCC allocated the 5.9 GHz band for Dedicated Short-Range Communications (DSRC) service—a service ostensibly designed to allow car-to-car communications to help reduce accidents. In the 20 years that have past, DSRC technology has proven a bust and most auto manufacturers have moved on to other standards such as Cellular Vehicle to Everything (C-V2X) that would accomplish the same public safety goals.

But while DSRC has languished, Wi-Fi has flourished—so much so that the unlicensed spectrum used by Wi-Fi networks is now congested to the breaking point.

According to FCC Commissioner Jessica Rosenworcel, “there are over 9 billion Wi-Fi enabled devices. Before the end of the decade, we will see as many as 50 billion new devices connecting to our networks through the internet of things. Add this up, and we will need a significant swath of new unlicensed spectrum to keep up with demand.”

As the 5.9 GHz band is clearly under-utilized (if not passed over), logic dictates the band (or at least a significant portion thereof) should be repurposed for general unlicensed use.

Recognizing the obvious, last May FCC Chairman Ajit Pai announced that his agency would initiate a public rulemaking proceeding to take a “fresh look” at the 5.9 GHz band.

According to Pai, all of the options would be on the table, including:

  1. keeping the status quo;
  2. allocating the 5.9 GHz band for C-V2X specifically or for automotive communications technologies generally;
  3. allowing for sharing between unlicensed devices and automotive communications technologies in the lower 45 MHz of the band while reserving the upper 30 MHz exclusively for vehicle-to-vehicle technologies;
  4. splitting the band, with the lower 45 MHz allocated exclusively for unlicensed and the upper 30MHz allocated exclusively for vehicle-to-vehicle technologies; and
  5. allocating the entire 75 MHz band exclusively for unlicensed use.

Although many in Washington expressed support for the chairman’s “fresh look,” Transportation Secretary Elaine Chao did not want to have this conversation and requested the agency to postpone the rulemaking. Acquiescing to Washington politics, the day after his announcement, the chairman pulled the item. Another spectrum turf war involving government agencies was engaged.

A Fight Not Worth Fighting

With all due respect to Secretary Chao, given the myriad of legitimate spectrum priorities of the DOT, perhaps the 5.9 GHz fight is not a dispute worth extending precious political capital upon.

First, unlike the spectrum currently used to help airplanes navigate across the skies (e.g., Global Positioning Service (GPS) and Very High-Frequency Omnidirectional Range (VOR) navigation) or spectrum used for Positive Train Control, one can hardly consider DRSC a “mission critical” service for the DOT. In fact, it is a service that after two decades of development has yet to be meaningfully deployed.

Making matters worse, the National Transportation Safety Board found that it will take at least another three decades before the majority of vehicles on the road have DSRC capability. As Commissioner Rosenworcel wryly quiped, “Fifty years from spectrum start to finish is a long time. I don’t know about you, but I’m hoping we will have flying cars by then.”

Second, the FCC’s Office of Engineering and Technology’s (OET) found after extensive tests that Wi-Fi devices’ can easily coexist with DRSC operations in the 5.9 GHz band.

The lack of interference from sharing the 5.9 GHz band stands in contrast to the case of Ligado Networks, who is currently petitioning the FCC to grant it an Ancillary Terrestrial Component exemption for its Mobile Satellite Service (MSS) despite significant unresolved interference concerns in adjacent bands (including GPS and other MSS service providers) used for DOT mission-critical public safety purposes.

Finally, having the FCC initiate a rulemaking to take a “fresh look” is only the first step in evaluating what to do the 5.9 GHz band. If the DOT has legitimate concerns about repurposing the band, then it can file comments in the record (which protocol dictates the FCC should accord deference as a fellow branch of government) and let the public examine the merits of their arguments.

FCC Commissioner Michael O’Rielly put the matter bluntly: “It is pure folly to believe that DSRC will ever work as envisioned, as time and technology advancements elsewhere have undermined previous use cases.”

Perhaps after 20 years with nothing to show for it, it’s time to throw in the towel on DRSC and redirect this prime spectrum to an immediate and important use. Since it lies adjacent to existing Wi-Fi spectrum, repurposing the 5.9 GHz band would facilitate a contiguous 160-megahertz channel that would go a long way towards alleviating spectrum exhaust for unlicensed use.

A deliberate “fresh look” investigation of the 5.9 GHz is warranted. The FCC should proceed post haste.

This column does not necessarily reflect the opinion of The Bureau of National Affairs, Inc. or its owners.

Author Information

Lawrence J. Spiwak is the president of the Phoenix Center for Advanced Legal & Economic Public Policy Studies, a non-profit 501(c)(3) research organization that studies broad public-policy issues related to governance, social and economic conditions, with a particular emphasis on the law and economics of the digital age.

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