7/7 – Public Interest FCC Comments on Wi-Fi Sharing of 5.9 GHz Auto Industry Spectrum
On July 7, OTI submitted FCC comments on Wi-fi sharing of 5.9 Ghz spectrum with the auto industry. Read the full comments here.聽
Summary
The undersigned members of the Public Interest Spectrum Coalition (hereinafter the聽鈥淧ublic Interest Organizations,鈥 or 鈥淧IOs鈥) strongly supported the Commission鈥檚 2013 proposal聽to expand unlicensed public access to 775 contiguous megahertz across the 5 GHz band, thereby聽enabling gigabit-fast and more affordable Wi-Fi connectivity made possible by the existing聽802.11ac Wi-Fi standard. The beneficial and mushrooming impact of unlicensed spectrum on the聽availability and affordability of mobile Internet access 鈥 and on the telecom sector and the U.S.聽economy more generally 鈥 is well documented. Wi-Fi is the workhorse of the Internet that聽currently carries an average 80 percent of all mobile device data traffic 鈥 and does so in an聽Public Notice, Revision of Part 15 of the Commission鈥檚 Rules to Permit Unlicensed National Information聽Infrastructure (U-NII) Devices in the 5 GHz Band, ET Docket No. 13-49 (rel. June 1, 2016) (鈥淧ublic Notice鈥).聽incredibly democratic and efficient manner through end-user networks and small cell spectrum聽re-use. Expanding unlicensed and wider-channel access to frequencies above 5 GHz can聽complement the use of licensed spectrum and facilitate new market entrants, services and聽applications that rely solely on unlicensed.
First, we strongly support opening the 5850-5925 MHz (U-NII-4) band for shared and聽unlicensed use, subject only to necessary interference protections for band incumbents.聽Contiguous unlicensed access to at least the lower 40 megahertz of U-NII-4 band, combined with聽technical rules harmonized with the U-NII-3 band, will enable access to 80 and 160 megahertz聽channels which can greatly amplify the potential increases in capacity for Wi-Fi operations.聽Accordingly, the Public Interest Organizations urge the Commission to lead and expedite a聽collaborative testing process aimed at a win-win compromise that doubly benefits nearly all聽Americans by enabling two services 鈥 DSRC and U-NII devices 鈥 to coexist and share at least聽the lower portion of the 5.9 GHz band without risk of harmful interference to truly delay-聽sensitive safety-of-life V2V or V2I communications.
Second, the Public Interest Organizations believe that the re-channelization approach to聽sharing strikes the best balance between DOT鈥檚 legitimate interest in promoting crash avoidance聽and the Commission鈥檚 interest in promoting ubiquitous broadband connectivity and innovation.聽Since both DSRC safety-of-life applications and expanded broadband capacity can deliver聽important benefits for virtually all Americans, the Commission should strive to enable both of聽these compelling public interest outcomes.
The critical factor in striking this balance is the distinction between real-time safety and聽other non-safety (or non-time-critical) DSRC applications. By dedicating three channels聽exclusively to DSRC safety applications 鈥 including the dedicated 10 megahertz BSM channel聽needed to implement DOT鈥檚 proposed V2V mandate 鈥 the Qualcomm proposal virtually聽eliminates the risk of interference with safety-of-life applications, while at the same time聽adhering to the FCC鈥檚 evolving principles of spectrum efficiency and flexibility that require聽public safety allocations to be narrowly defined and 鈥渓imited鈥 to 鈥渢he amount of spectrum . . .聽which ensures that those [compelling public interest] objectives are achieved.鈥 Our groups聽generally support proposals to re-channelize the band so that V2V Basic Safety Messaging and聽other latency-sensitive safety-of-life DSRC applications will have two or three dedicated safety聽channels (20 or 30 megahertz) at the top of the ITS band, furthest away from any potential聽interference from unlicensed operations in U-NII-3 and in the bottom 40 megahertz of U-NII-4.
The Public Interest Organizations urge the Commission to reject the detect-and-avoid聽approach outlined in the Public Notice. The fundamental problem with the Cisco approach, as聽currently described, is that it would not permit the economically feasible deployment of聽unlicensed technologies, particularly Wi-Fi. Vacating the entire band if any DSRC transmission聽is detected on any channel across a 100 megahertz range (the entire 5.9 GHz band and the聽adjacent 5825-5850 MHz) is an extreme restriction that may effectively exclude 802.11ac Wi-Fi聽and future unlicensed innovation from the band. Since a V2V mandate would require that聽vehicles use the BSM safety channel to constantly communicate their location, heading, speed聽and other data to surrounding vehicles, the continual and ubiquitous traffic on this single 10 MHz聽channel could exclude unlicensed devices from the entire 5.9 GHz band, with the exception of聽those inside well-shielded buildings and away from streets and vehicles. The Cisco detect-and-聽avoid approach would make unlicensed devices substantially more expensive and restrict the聽benefits of extended gigabit Wi-Fi connectivity to indoor enterprise Wi-Fi systems (such as聽hotels, convention center, corporate campuses), while denying those benefits to individual聽households and other business establishments located close to streets and vehicles.
Third, the Public Interest Organizations strongly agree with Commissioner O鈥橰ielly and聽others that non-safety of life commercial and informational DSRC applications should share at聽least the lower portion of the band on an equal basis with unlicensed operators. The聽Commission鈥檚 1999 ITS allocation order contemplated, and reserved for later judgment, that聽non-safety functions could operate on an unlicensed basis separate from the safety-of-life DSRC.聽And certainly after more than 15 years of leaving the band fallow, even the speculative non-聽safety applications suggested by the auto industry (such as advertising, social media, navigation,聽in-vehicle displays and electronic payments) have been or soon will be subsumed by more聽efficient general purpose cellular and Wi-Fi networks 鈥搃ncluding the high-capacity and low-聽latency benefits of general purpose 5G networks 鈥 at least a decade before NHTSA expects聽DSRC to achieve a critical adoption rate sometime in the 2030s.
Fourth, and relatedly, the fundamental framework of FCC spectrum allocation policy has聽evolved since 1999 in a manner that completely contradicts auto industry pleas for an auction-free and effectively exclusive silo of special-purpose spectrum with a designated technology聽(DSRC) that will be obsolete (if it isn鈥檛 already) long before the 20-to-30-year deployment period聽NHTSA estimates is needed even before it can judge whether DSRC is effective for crash聽avoidance. Leaving most of the band鈥檚 capacity essentially fallow for the indefinite future is聽distinctly inconsistent with FCC spectrum management principles adopted in the years since the聽original 1999 ITS allocation. It also runs counter to the Obama Administration鈥檚 historic聽initiative to open underutilized bands for sharing to the greatest extent feasible.
The Commission鈥檚 effort since 1999 to move away from silos of special-purpose use and聽toward more intensively-used and flexible general-purpose use makes the distinction between聽DSRC鈥檚 anticipated real-time safety and non-safety applications critical. In 2002 the Spectrum聽Policy Task Force (SPTF) Report recommended that the Commission 鈥渆schew command-and-control regulation鈥 of spectrum use. The Task Force Report emphasized that exceptions made聽for public safety or other public interest allocations should be narrowly defined 鈥渁nd the amount聽of spectrum . . . limited to that which ensures that those [compelling public interest] objectives聽are achieved.鈥 Embracing this trend, the 2010 National Broadband Plan criticized the traditional聽approach to allocating spectrum 鈥渙n a band-by-band, service-by-service basis, typically in聽response to specific requests for service allocations鈥 and concluded that 鈥渢he failure to revisit聽historical allocations can leave spectrum handcuffed to particular use cases and outmoded聽services, and less valuable and less transferable to innovators who seek to use it for new聽services.鈥
Finally, the auto industry鈥檚 recent Petition for Reconsideration challenging the out of聽band emission (OOBE) limits adopted by the Commission for unlicensed use of the adjacent U-NII-3 band reinforces just how easily the interference concerns of the auto industry could be聽addressed through re-channelization. By re-channelizing to physically separate the real-time聽life-and-safety channels from unlicensed OOBE, the automakers鈥 concern about interference to聽BSMs can be completely satisfied, removing virtually all risk of interference between future Wi-Fi and V2V safety signaling. This can be done without undue delay since there are no DSRC聽deployments and DOT is expected to give automakers a multi-year transition period before聽requiring the installation of at least a single-radio DSRC system in every new car sold.
You can download the full comments below:聽