3/9 FCC Comments Urging Commission to Open 5.9 GHz Band for Unlicensed Use

New America's Open Technology Institute filed comments and an Issue Brief with the Federal Communications Commission ("the Commission") responding to a Notice of Proposed Rulemaking (NPRM) that proposed freeing up 45 megahertz of spectrum in the 5.9 GHz band for unlicensed use, and retaining 30 megahertz of spectrum for auto safety purposes. Public Knowledge also signed onto the comments. OTI and PK argued that the 5.9 GHz band, which has been reserved for auto safety technologies and been unused for the past 20 years, is an essential need to strengthen Wi-Fi as it becomes increasingly congested with mobile and fixed broadband traffic. The extra capacity that the spectrum in the 5.9 GHz band would offer Wi-Fi would also be crucial for next-generation Wi-Fi services and the growing amount of devices and uses for Wi-Fi in education, manufacturing, health care, and farming, among other use cases that are still developing. OTI and PK also highlighted the importance of improving Wi-Fi services to address what will be a worsening digital divide in a 5G world. In addition to the comments, OTI also filed an issue brief on the topic to detail the history and specifics of this band and its significance to the future of connectivity and the digital divide.

Below is an introduction and summary of the comments:

The virtually unused 5.9 GHz band has become a roadblock to an immensely valuable Wi-Fi superhighway comprised of contiguous wide channels capable of delivering gigabit-fast and affordable wireless connectivity to all of America’s homes, workplaces, enterprises, schools and public spaces. Our groups strongly support the Commission’s proposal reallocate at least 45 megahertz of the virtually unused 5.9 GHz band for unlicensed use. This increment of additional unlicensed spectrum is critical for consumers and the economy to the extent that it creates the first unencumbered 160 megahertz channel needed to support the next generation of Wi-Fi technology that will enable Americans in all areas of the country to access gigabit-fast and more affordable 5G-capable applications and services.

Leaving the entire 5.9 GHz allocated for auto safety communication (whether DSRC or Cellular V2X) would impose high costs on consumers with little return on the horizon. The 45 megahertz the Commission proposes opening for unlicensed use is absolutely essential to the future of Wi-Fi, specifically as the industry moves to next-generation Wi-Fi services—Wi-Fi 6— to support faster speeds, lower latency, more devices, and new use cases.

Critically for U.S. consumers and businesses, reallocating the lower 45 megahertz of the 5.9 GHz band for unlicensed use would create the first and only gigabit-capable Wi-Fi channel that is not subject to the detect-and-avoid requirements that have hobbled the U-NII-2 band (shared with military radar). If the technical rules for this new 160 megahertz channel are compatible with today’s U-NII-3 band, this added spectrum for unlicensed use would ensure the swift availability of Wi-Fi 6’s capabilities without undue delay or reduced performance. Consumers, schools, libraries, small businesses, manufacturers, retailers and other public spaces will all be able to avail themselves of the improvements that come with Wi-Fi 6 quickly.

OTI and PK strongly support the Commission’s proposal to limit V2X operations to 30 megahertz of exclusive-use spectrum for public safety applications. The proposal to limit V2X to the 30 megahertz needed for critical public safety needs follows Commission precedent, provides the auto industry with sufficient spectrum to deploy critical public safety communications, allows for a technology-neutral competition among V2X approaches, and limits the risk that 75 megahertz of valuable spectrum will continue to lie fallow, while also allowing the industry to make use of other bands of spectrum for non-critical commercial and safety-related applications. As NHTSA emphasized in its analysis leading up to the proposed DSRC mandate, a V2X system of real-time public safety communication requires at most 20 or 30 megahertz. Regulatory agencies around the world have concluded that 30 megahertz or less is sufficient for V2X safety communications.

It is important to note that when the Commission allocated 75 MHz to DSRC 20 years ago, the auto industry intended to use the band for commercial purposes as well as for collision avoidance. The Commission permitted this in 2004 as a mechanism for encouraging adoption. Today, such incentives are neither necessary nor desirable. They provide an unfair advantage to auto licensees at the expense of the public, by giving them free commercial use of valuable spectrum under the guise of public safety.

We urge the Commission to consider moving ITS operations to another band to better harmonize C-V2X services with mobile 5G networks. It is far from optimal to wedge a public safety communication service between two unlicensed bands. If an alternative band is available, it could provide C-V2X with more spectrum, better propagation, and a less intensively-used spectrum environment in adjacent bands, facilitating an even more robust win-win for consumers and the U.S. economy. An additional consideration is the extreme uncertainty that even C-V2X will be deployed in every new vehicle and added to roadside infrastructure at a scale that will make it reliable as an automated safety communication system

An alternative and potentially better band of spectrum for ITS operations, and C-V2X specifically, is the 4.9 GHz band – 50 megahertz of extremely underutilized spectrum already allocated for public safety operations. At most 3.5% of potential licensees use the band, as the Commission has lamented in a pending rulemaking seeking ideas for more intensive use of the band. Because of its light usage, substantial bandwidth and mid-band propagation characteristics, OTI and PK urge the Commission to study the 4.9 GHz band as a more appropriate alternative for V2X safety communications in particular.

C-V2X, which is still under development, is a particularly good candidate for alternative and ideally better spectrum. C-V2X technology is not compatible with DSRC services and is in no way tethered to the 5.9 GHz band. Once C-V2X safety signaling is actually deployed and viable on 20 megahertz, the Commission could decide to expand ITS at 4.9 GHz to as much as 50 megahertz, thereby allowing C-V2X to evolve toward its eventual integration with general purpose mobile 5G mobile networks.

Finally, the Commission should combine the pending Petition in RM-11771 with this rulemaking. Even if the rulemaking is not formally consolidated, ITS licensees should be restricted to non-commercial, safety-related services and receive no allocation of free licensed spectrum to support commercial uses of the spectrum. As part of re-banding 5.9 GHz, in the event the Commission allocates 10 MHz to DSRC, the Commission should clarify that the 10- MHz “control channel” in the DSRC band plan will be replaced by a 10 MHz non-commercial use DSRC channel. The remaining 20 MHz assigned for Cellular V2X should be conditioned on a requirement that non-commercial collision avoidance and public safety use prioritized over any commercial use. Ideally, however, the Commission would allocate the entire ITS auto safety allocation (whether or not it remains at 5.9 GHz) for C-V2X as the safer, more efficient technology.