Commenters Provide FCC Broad Support for 5.9 GHz Geofencing Proposal
The FCC received unanimous support from commenters that have filed so far for an NTIA proposal that calls for using geofencing to allow higher equivalent isotropically radiated power limits for cellular vehicle-to-everything on-board units in the 5.9 GHz band (see 2406100032). Comments were posted on Friday and Monday (docket 19-138).
The FCC changed rules for the 5.9 GHz band in 2020, during the late stages of the last administration, despite Department of Transportation concerns (see 2011180043). The revised rules allocated 45 MHz of the band for Wi-Fi, in the U-NII-4 band, and 30 MHz for cellular vehicle-to-everything technology. Final rules for C-V2X have proven more elusive (see 2405150036).
The Alliance for Automotive Innovation “appreciates” that NTIA and the commission “are seeking to identify a pathway through optional geofencing” for on-board units (OBUs) to operate “with a less restrictive equivalent isotropically radiated power outside of federal radiolocation system coordination zones,” said the group, also called Auto Innovators.
The industry needs certainty “to support deployment of cutting-edge C-V2X safety applications at scale,” Auto Innovators said: Approval of final rules would “help address a growing U.S. automotive safety crisis, maintain American competitiveness in automotive innovation, and encourage harmonized global deployment of CV2X technologies in the Upper 5.9 GHz band.”
The proposal was also supported in a joint filing by the 5G Automotive Association, the American Association of State Highway and Transportation Officials, the Institute of Transportation Engineers and the Wireless Infrastructure Association. OBUs equipped with geofencing technology should be allowed to transmit with up to 33 dBm EIRP Within ± 5 degrees of the horizontal plane, the groups said. “Geofencing technology can ensure that an OBU entering an NTIA-defined power reduction zone lowers its transmit power level to levels NTIA deems necessary to protect federal systems,” the joint filing said.
If the FCC finds that 5.9 GHz C-V2X devices outdoors can operate at higher power levels, while protecting federal radiolocation systems, “it should simultaneously make a similar determination for 5.9 GHz Wi-Fi devices,” NCTA commented. “There is a strong record supporting the adoption of rules for outdoor use of U-NII-4, and the Commission should promulgate those rules alongside any rules for C-V2X operations,” the cablers said. NCTA said only standard power Wi-Fi devices, operating at 33 dBm EIRP, should face geographic restrictions and, because they are at fixed locations, the devices shouldn’t be required to implement geofencing technology.
NCTA noted that remaining dedicated short-range communications (DSRC) users no longer tap the spectrum. C-V2X in part has replaced DSRC, which was slow to take off. “There is no remaining question regarding the Commission’s authority to modernize the 5.9 GHz band or its ability to exercise its expert technical judgment regarding how to accommodate both unlicensed operations and automotive technologies,” NCTA said. Indoor-only use “needlessly limits U-NII-4’s overall potential.”
ITS America said it appreciates “the flexibility” the proposal “provides to C-V2X operations with regard to power levels.” But updating the geofencing parameters “poses challenges” and will require “close collaboration” among NTIA, DOT and the transportation industry, ITS America said.