While a host of companies would like to see dedicated short-range communications (DSRC) laid to rest, Toyota representatives recently visited the FCC to extol its virtues and stress the importance of protecting it from harmful interference from unlicensed devices.
The meetings with Toyota representatives and FCC legal advisers to Chairman Ajit Pai and Commissioner Brendan Carr followed comments by the NCTA - The Internet & Television Association filed earlier this month (PDF) in which the association blasted DSRC for problems still unresolved after 20 years. NCTA argued that opening the spectrum to Wi-Fi technologies would immediately create value.
The DSRC band has been the subject of debate for years as the auto industry has been developing 802.11p technology for vehicle-to-vehicle communications (V2V). Some stakeholders grew impatient with the auto industry’s efforts to use DSRC and identified the upper 5.9 GHz band as worth sharing with Wi-Fi.
In its September 20 ex parte filing (PDF), Toyota recounted its meetings with FCC advisers where it noted the significant progress that has been made with respect to DSRC development and deployment since the commission first initiated the 5 GHz proceeding in 2013. Toyota representatives noted that market leaders in Japan (Toyota), Europe (Volkswagen) and the United States (General Motors) have now either begun deployment of DSRC technology or announced a specific deployment plan for it.
Toyota also pointed out that at a recent European (CEPT CPG PTD) spectrum regulation meeting, regulators from countries throughout Europe concluded—based on a technical report that was prepared at their request by a number of DSRC and Wi-Fi stakeholders—that it was not possible to adequately protect DSRC communications from harmful interference using sharing mechanisms currently under consideration. “In fact, Qualcomm, which has previously advocated for sharing, submitted a contribution explicitly concluding that ‘spectrum sharing for RLAN [Radio LAN] and ITS considering safety-related applications in the 5.9 GHz band should not be recommended,’” Toyota wrote in is ex parte filing.
Toyota representatives expressed their support for the testing that’s currently underway at the FCC, reiterating support for current testing plans that include an examination of cross-channel interference and co-channel interference.
But naysayers to DSCR say there's no international harmonization of DSRC and that newer technologies like Cellular-V2X can support vehicle safety in existing cellular bands without a government mandate or spectrum subsidy for DSRC. In fact, Cellular-V2X direct communications is designed to be operated on the ITS 5.9 GHz band without the need for a Subscriber Identity Module (SIM), cellular subscription or network assistance—that's the scenario how Cellular-V2X direct communications would be used, according to Qualcomm.
NCTA said Japan has allocated spectrum for DSRC use, but the frequencies it uses do not align with the U.S. 5.9 GHz band. Although Europe has set aside spectrum in the 5.9 GHz band for use by DSRC-based Intelligent Transportation Services (ITS), like Japan, it also has focused primarily on vehicle to infrastructure (V2I) rather than vehicle to vehicle (V2V).
“Many countries appear to be shifting their attention away from the last-generation idea of DSRC warnings to a more modern plan to use higher band spectrum to support autonomous vehicle technology,” NCTA said.
Now that the FCC is up to its full five members again, it’s possible something could happen on the 5.9 GHz front. Importantly, Democratic Commissioner Jessica Rosenworcel and Republican Commissioner Michael O’Rielly have been united in their desire to resolve outstanding issues in the 5.9 GHz band.
Editor's Note: Article updated September 23 with additional information about how Cellular-V2X is designed to work.