Qualcomm, Broadcom and NCTA—The Internet & Television Association are appealing to the current three-member FCC to act now on what they consider to be the single best near-term opportunity for expanding the nation’s unlicensed spectrum resources. But in so doing, they’re going up against the auto industry, which continues to oppose rechannelization of the 5.9 GHz band.
Years ago, the government set aside the 5.9 GHz band specifically for the auto industry to develop technology using dedicated short range communications (DSRC) to transmit data, such as location, direction and speed, to nearby vehicles. That technology has been slow to emerge while the need for more Wi-Fi spectrum has grown. Qualcomm, Broadcom and NCTA believe the FCC can achieve its goal of protecting emerging crash-avoidance technologies and meeting the demand for Wi-Fi by rechannelizing the 5.9 GHz band, the core proposition being to protect latency-sensitive safety-critical services by moving them away from other traffic.
“While DSRC safety technologies may someday become widespread, this is the perfect moment to put in place forward-looking, efficiency-maximizing sharing rules, without the need for challenging relocation, database, or SAS approaches seen in other bands,” the Wi-Fi proponents say in their Feb. 3 filing. “The time to act is now, and the rechannelization proposal we support provides a clear path to achieving these benefits while protecting emerging latency-sensitive, safety-critical DSRC applications.”
The problem, they say, is not that they want to do anything to harm the auto-industry’s need for DSRC for crash-prevention technologies; rather, they say the “tenor and obfuscation of recent filings make it increasingly clear that detect-and-vacate proponents oppose rechannelization not because of technical concerns related to crash-avoidance, but in order to protect the 5.9 GHz band for their non-safety commercial applications.”
However, “it appears that DSRC proponents want more than this. They appear to want to secure all 75 MHz of the 5.9 GHz U-NII-4 band for entertainment, telemetry, commerce, and other non-safety applications without willingness to provide any meaningful sharing opportunities,” they said.
Indeed, automakers want the commission to retain the existing DSRC band plan. Toyota representatives recently met with FCC staff to reiterate concerns about degradation of DSRC that they think would occur if the rechannelization were to happen. They also discussed growing interest in the possibility of opening up the 6 GHz band for unlicensed use and potential interference with DSRC if such use were permitted as low as 5.925 GHz.
Qualcomm, Broadcom and NCTA recommend that the commission designate the upper 30 MHz of the U-NII-4 band exclusively for DSRC to accommodate latency-sensitive safety critical signals and permit Wi-Fi to share the lower 45 MHz of the band with other DSRC services that are non-latency-sensitive such as e-commerce, informational and entertainment applications.
The current DSRC rules designate two 10- MHz channels for safety-critical applications, while “the rechannelization proposal provides three 10- MHz channels exclusively for safety-critical applications, thereby increasing the amount of spectrum reserved for safety signals, rather than decreasing channels as some automakers incorrectly assert,” the companies said. “Consequently, the rechannelization approach designates more than sufficient spectrum for latency-sensitive safety-critical systems.”
In December, the U.S. Department of Transportation (DoT) said it was moving forward with a proposal to mandate DSRC for vehicle-to-vehicle (V2V) on new light-duty vehicles.