Wi-Fi Advocates Seeking Framework Order Opening 5.9 GHz Band

Officials on both sides said testing, as envisioned by the FCC, is unlikely to be wrapped up before early 2017, which could push a final decision until the next administration, after the Tom Wheeler chairmanship. The latest is that the commission plans a three-stage testing process, moving from the lab to in-vehicle to multi-vehicle tests, said a DSRC advocate. The timing depends on how long testing takes, the official said.

“Whether the FCC will make any decision before the end of the year and the presumed end of the Wheeler era will probably depend in large part on whether the White House gives DOT [the Department of Transportation] a go-ahead for its proposed vehicle-to-vehicle mandate for auto safety, and whether any conditions about sharing the channels not needed for real-time safety signaling is explicitly or implicitly part of that,” emailed Michael Calabrese, director of the Wireless Future Project at New America. “If the administration signals support for sharing the band, our hope is that Chairman Wheeler will proceed this year to a framework order -- as the commission is doing next week vis-à-vis spectrum for 5G -- that ends the debate about whether Wi-Fi and DSRC will share the band. Technical issues on sharing could then be kicked to a further notice, and testing would go on into next year, but at least there would be certainty about the policy direction.”

The FCC could approve a “framework” order in the October/November time frame, said Public Knowledge Senior Vice President Harold Feld. “Other than that, it’s not clear how much data parties will submit.”

A key question teed up by the FCC is whether it will rechannelize the 75 MHz 5.9 GHz band, with 30 MHz at the top divided into three safety channels that would be off-limits to unlicensed devices, as proposed by Qualcomm and other Wi-Fi advocates. Cisco, working with automakers, urged a "detect and avoid" approach that would leave the band intact (see 1604280043).

Public Safety

“Decisions over sharing the Safety Spectrum should be driven first and foremost by public safety,” said Global Automakers President John Bozzella in a news release. “Vehicle-to-vehicle (V2V) technology, which is ready today, has the potential to prevent over 1,000 deaths a year. The future of this significant lifesaving technology lies in the hands of the FCC.”

In a filing with other automotive groups, Global Automakers opposed rechannelization. Detect and avoid is “the superior choice for preventing interference to DSRC,” the groups said. “It is also the least disruptive to DSRC and the legitimate investment-backed expectations of its public and private sector proponents, while at the same time providing meaningful 5.9 GHz band access for unlicensed devices.”

If the FCC changes the band plan, automakers “would have to discard decades of costly research and go back to the drawing board to redesign DSRC to be compatible with a re-channelized band,” the automakers said. Vehicle-to-vehicle warning systems allow vehicles to exchange data on heading, speed, and location, “so that the vehicles can sense threats and hazards with a 360 degree awareness of the position of other vehicles and the threat or hazard they present; calculate risk; issue driver advisories or warnings; or assist in taking preemptive actions to avoid and mitigate the damage caused by crashes,” the groups said. The Alliance of Automobile Manufacturers, the Intelligent Transportation Society of America and Denso International America also signed the filing.

General Motors, which announced plans to deploy DSRC in some vehicle models this year, supported the auto industry comments. The FCC’s current 5.9 GHz band plan was “designed to prioritize safety and provide a blueprint for avoiding harmful interference,” GM said in comments. “Based on the Commission’s channelization plan, and relying on the assumption that the Commission would keep the 5.9 GHz band free from harmful interference, GM and other automakers invested considerable resources in developing safety of life solutions for V2X [vehicle-to-infrastructure] communication systems using DSRC.”

Automakers got support from local government groups eager for deployment of DSRC. The Port Authority of New York and New Jersey said it understood why the FCC wants to open the band for unlicensed use. “However, we believe every effort must be made to ensure any proposed technical solution guarantees, through rigorous testing, interference-free operation of the DSRC safety-critical applications while allowing for spectrum sharing in the 5.9 GHz band,” the authority said. The National Safety Council also filed in support of DSRC. “If we are to eliminate preventable deaths in our lifetime, it cannot be done without massive, near-term gains in highway safety,” the council said.

But Wi-Fi advocates stressed the importance of the 5.9 GHz band, saying DSRC can be protected while setting aside spectrum for broader unlicensed use.

NCTA Wants Action

NCTA asked the FCC to move quickly, saying 30 GHz is spectrum enough to support anti-crash technologies deployed as part of DSRC. “The Commission should not grant non-crash avoidance DSRC operations the extraordinary special status of a free nationwide exclusive license,” NCTA said. “And the Commission should not privilege these applications over other operations simply because they use the DSRC protocol.”

DSRC operations will require no more than 10 MHz of spectrum for the exchange of basic safety messages, NCTA said. Other operations, from entertainment to social media to maps and parking, shouldn’t be protected, the group said. DOT suggested the 5.9 GHz DSRC service channels “could be used for everything from paying tolls, to finding parking spots and paying parking fees, paying at drive-thrus, sending notifications to the driving public about ‘points of interest,’ route guidance and navigation, sending instant messages between vehicles, and even video downloads,” NCTA said.

Public interest groups said allowing unlicensed use of the lower 40 MHz of the band “will enable access to 80 and 160 megahertz channels which can greatly amplify the potential increases in capacity for Wi-Fi operations.” The groups agreed with NCTA that the FCC needs to distinguish "between real-time safety and other non-safety (or non-time-critical) DSRC applications.” The rechannelization proposal would dedicate up to three 10 MHz channels to safety applications, they said.

The Cisco approach isn’t workable, the public interest groups said. “Vacating the entire band if any DSRC transmission is detected on any channel across a 100 megahertz range (the entire 5.9 GHz band and the adjacent 5825-5850 MHz) is an extreme restriction that may effectively exclude 802.11ac Wi-Fi and future unlicensed innovation from the band.” The Open Technology Institute at New America, Public Knowledge, Engine, Common Cause and Next Century Cities joined the filing.

“Rechannelization will most reliably protect DSRC safety-of-life communications because it places these important messages in spectrum that remains exclusively allocated to DSRC and is as far away as possible from unlicensed operations” elsewhere in the 5 GHz band, Qualcomm said. “We are eager for the Commission to provide clarity on spectrum sharing in this band, so Qualcomm and other DSRC technology providers can ensure the rapid, broad, and successful deployment of DSRC services that improve road safety by supporting low-latency communications among vehicles, pedestrians, and roadway infrastructure.”

Cisco said trying to distinguish between safety and non-safety uses of DSRC creates a “false distinction,” since “all DSRC channels are planned for use by safety-related communications.” GM is equipping the 2017 Cadillac CTS with DSRC devices, Cisco said. “There is no longer anything theoretical about DSRC equipment: manufacturers have moved past the testing phase, received their required Commission approvals and are putting equipment into production for commercial deployment under the current DSRC band plan.”

“Wi-Fi will play an important role in driving the growth of global connectivity, delivering two-thirds of all Internet traffic by 2020, and the 5 GHz band continues to emerge as a critical resource in meeting growing demand," emailed Alexander Roytblat, the Wi-Fi Alliance's newly hired (see 1607080019) senior director-worldwide regulatory affairs. "Allowing unlicensed operations in the U-NII-4 portion of the 5 GHz band would help meet these demands and offer important benefits such as the ability for Wi-Fi equipment to utilize wider bandwidths to offer additional network capacity and higher speeds for applications such as streaming of high-definition video. The commission should therefore act as quickly as possible to make additional 5 GHz spectrum available for unlicensed operations.”