Report: 5.9 GHz DoT Analysis Failed to Consider Spectrum Sharing Impact

May 2, 2016–A 2014 research report released by the National Highway Traffic Safety Administration on a planned vehicle-to-vehicle (V2V) technology requirement in new light vehicles was flawed, in part because it failed to consider spectrum sharing in the 5.9 gigahertz band with Wi-Fi devices, according to a report released today. The report released today was prepared for the National Cable & Telecommunications Association with support from Comcast Corp. It was written by Coleman Bazelon and Lucrezio Figurelli of The Brattle Group

The 2014 NHTSA report was released along with an advance notice of proposed rulemaking (ANPRM) that took the next steps to require dedicated short-range communications (DSRC) V2V technology in new light vehicles (TRDaily, Aug. 18, 2014). An NPRM in the proceeding is expected to be released this month.

Separately, the FCC has circulated a public notice seeking comments to refresh its record in its 5.9 GHz band proceeding ahead of planned testing by the agency (TRDaily, April 22).

NHTSA’s 2014 report “presented preliminary estimates of the direct monetary costs of a potential V2V DSRC mandate and of the benefits in terms of reduced crash rates, fatality rates and crash severity under three different implementation scenarios,” the report released today noted. “However, while highlighting the economic practicability and the potential safety benefits of a mandate, the NHTSA’s analysis has several limitations and ultimately does not constitute a suitable analytical framework to evaluate the full set of benefits and costs of a mandate.

“Most importantly, the NHTSA’s analysis: 1. Only measures the incremental costs and benefits of the technology relative to the current state of vehicle-safety technologies, and not relative to an appropriate baseline that includes other expected safety improvements. 2. Does not consider the opportunity costs of the spectrum or whether alternative spectrum sharing scenarios could meet the technology’s objectives and requirements and promote its efficient use. 3. Does not consider the plausible externalities—positive or negative—that a mandate on V2V would have on investment in, and development of, substitute and complementary vehicle-safety technologies. 4. Does not attempt to monetize the welfare benefits of a mandate,” today’s report said.

“In addition to these major limitations, the NHTSA’s analysis suffers from many potential inaccuracies,” the report added. “The overall effect of these limitations and inaccuracies is to paint an overly optimistic picture of the current DSRC proposal and to fail to maximize total benefits by ignoring the opportunity cost of not sharing spectrum in the 5.9 GHz band with unlicensed uses. In this paper, we review and adjust the NHTSA’s analysis, and extend it to analyze the welfare effect of a V2V DSRC mandate under alternative policy configurations, relative to an alternative scenario in which V2V is not mandated.”

“To highlight the opportunity costs associated with spectrum use, we compare a mandate assigning the full 75 MHz of spectrum for exclusive DSRC use to an alternative scenario that conservatively provides for exclusive DSRC use of the upper 30 MHz of the 5.9 GHz band,” the report added. “Under the plan, originally proposed by Qualcomm, unlicensed Wi-Fi would only share the lower 45 MHz of the 5.9 GHz band. The proposal would capture the full safety benefits of V2V technology and at the same time promote efficient use of the scarce spectrum resource.”

The report stressed that “NHTSA’s inappropriate application of assumptions and baseline overstates the net benefit of a V2V DSRC mandate by hundreds of billions of dollars. Once the NHTSA’s assumptions are properly adjusted, the net benefits of a V2V DSRC mandate are dramatically reduced and, under some parameter assumptions, become negative. … The net benefits of a V2V DSRC mandate without spectrum sharing range between a net loss of $140 billion and a benefit of $442 billion, depending on the parameter assumptions. Conversely, the net benefits of a mandate allowing for shared use of the lower portion of the 5.9 GHz band would always produce large, positive benefits ranging between $191 and $744 billion.

The report continued, “Shared use of the lower portion of the 5.9 GHz band would both achieve the full safety benefits of V2V communications and maximize the value of the spectrum regardless of the parameter assumptions used. Shared use would produce a surplus ranging between $166 and $603 billion.”

During a conference call with reporters this morning on the report, Paul Margie, a partner at Harris, Wiltshire & Grannis LLP who is representing NCTA in the 5.9 GHz band proceeding, explained why the Brattle Group reports focuses on Qualcomm, Inc.’s band segmentation proposal and not Cisco Systems, Inc.’s sense-and-avoid proposal, in which V2V and Wi-Fi applications would share the entire 75 megahertz of the 5850-5925 MHz band

Mr. Margie said the Brattle Group was able to analyze “a discreet number of MHz” with the Qualcomm proposal.

He added that if there is a “version of the Cisco approach that would allow commercially reasonable investments in the band, I’m sure we would take a look at that as well. What we’re seeing now from the Cisco approach is not that, however.  Mr. Margie also said that the report released today would be submitted in DoT’s proceeding. He said his clients are hopeful that it will also help DoT consider the larger impacts of any actions it may take.

“We’re hoping that as DoT continues in their proceeding, that they do so in a way that allows the FCC and other administrative agencies …. to move forward in achieving the president’s goal of [freeing up] 500 MHz,” he said. “And we want to make sure that they are considering the impact and making sure they don’t tie the FCC’s hands.”

He also said it is good that the FCC plans to refresh its record and test “multiple sharing technologies.”

“We believe that sharing here is very possible, but we also believe that the FCC could set rules or could set a timetable that would make that sharing commercially not viable,” Mr. Margie added. – Paul Kirby, paul.kirby@wolterskluwer.com

Courtesy TRDaiy