FCC DSRC/Wi-Fi Testing Taking a Little Longer Than Planned, Says OET Chief

FCC Office of Engineering and Technology testing involving spectrum used for Wi-Fi and dedicated short range communications (DSRC) is taking a little longer than previously expected, and the results will help inform how the agency proceeds, commission officials said at a sometimes contentious FCBA CLE Wednesday. The goal was to finish the Phase I testing in January, but “you learn things as you go,” and the testing still is working on DSRC detection protocols, OET Chief Julius Knapp said. "We are trying to move things as fast as we can."

DSRC still hasn't been widely deployed, and Wi-Fi "is now a mainstay," said Erin McGrath, wireless aide to Commissioner Mike O'Rielly. Auto industry innovations like vehicular cameras and autonomous vehicles also necessitate a fresh look at how DSRC fits in, she said. She said current Phase I testing of prototype devices will inform agency decisions but added the commission also has to consider marketability. She said any protection of DSRC needs to be confined strictly to safety-of-life applications and use a narrow definition of those applications that doesn't apply to services like toll collection or entertainment systems.

The Phase I test plan is looking at RF characterization, benchtop interference testing and steps devices need to take to avoid interference, Knapp said. He said OET hopes to get data on the capability of Wi-Fi devices to detect DSRC signals and insight into what happens when signals are detected.

The FCC's NPRM regarding unlicensed devices in the 5 GHz band should look into the privacy issues related to non-safety DSRC applications, said Public Knowledge Policy Fellow John Gasparini. No one has developed an advertising application for DSRC, said Steve Bayless, Intelligent Transportation Society of America vice president-technology and markets. "That doesn't even seem to make sense" given the ubiquity of mobile phones, he said.

Other than generally agreeing the 5.9 GHz band is perhaps the best option for additional unlicensed spectrum, panelists were largely at opposite poles over rechannelization or detect-and-avoid as the best way to share between Wi-Fi and DSRC. At times, panelists were speaking over one another on such issues as why DSRC still hasn't been widely deployed. Some arguments for rechannelization “are somewhat disingenuous,” said Ari Fitzgerald of Hogan Lovells, who represents auto industry clients. Countered Paul Margie of Harris Wiltshire who has wireless clients, detect-and-avoid “is a poison pill" with a detection level so low and a channel vacation size so high that no one could commercially deploy in the band.

The auto industry favors unlicensed spectrum and has been willing to consider sharing the band -- allocated for intelligent transportation services -- with Wi-Fi, Fitzgerald said, contrasting it with reluctance about sharing in other spectrum issues like TV white spaces. But the detect-and-vacate protocol is the only one that satisfies auto industry criteria, he said.

Since DSRC deployment has taken longer than expected and Wi-Fi use is exploding, "now is the perfect time" to revisit DSRC rules, said John Kuzin, Qualcomm regulatory counsel. Backing rechannelization, he dismissed the argument detect-and-avoid works better because it won't require DSRC rules changes: "Change can be a good thing." He also said detect-and-vacate isn't viable because of the degree to which it requires Wi-Fi to vacate the band when a DSRC signal is detected and because failed detections could mean safety messages won't get through Wi-Fi interference. Rechannelization, meanwhile, clusters basic safety message channels in the upper portion of the band, away from such interference, he said.

The 5.9 GHz band "is the single best near-term opportunity" for expanding unlicensed spectrum, NCTA said in a blog post Wednesday. Other users of the band haven’t moved beyond pilot projects, so with an almost empty band to work with, sharing is far less complicated than in any other spectrum band, NCTA said, adding the 5.9 GHz band is right next to an existing Wi-Fi band that millions of consumers are already using and that means lower equipment costs for consumers and a far faster roll out. The 5.9 GHz band is also the only pending band that innovators can use for the newest Wi-Fi technology, Gigabit Wi-Fi, NCTA said, adding it’s the only band that would give consumers a full-powered, contiguous Gigabit Wi-Fi channel.

NCTA also said it Qualcomm and Broadcom see a better path that protects DSRC safety applications and permits Wi-Fi by rechannelizing the band. They said the FCC can provide three exclusive channels for safety services, and allow non-safety DSRC to share fairly with Wi-Fi in the rest of the band using mechanisms already built into the standards for both technologies. NCTA, Broadcom and Qualcomm also urged such 5.9 GHz rechannelization in a letter last week to the FCC (see 1702030043).