After following the debate over Dedicated Short Range Communications (DSRC) versus Cellular Vehicle-to-Everything (C-V2X), I have come to two conclusions. First, it’s a mess. Second, it would be nice if the world could just declare DSRC as dead and move on, but that’s not going to happen even if it appears to be clinging to life support.
Which is too bad, because there’s this 5.9 GHz spectrum laying fallow that the Wi-Fi community is champing at the bit to use, and the cellular world is ready to go full steam ahead with C-V2X.
New America’s Open Technology Institute (OTI) hosted a panel in Washington, D.C., on Friday that brought many of these issues to the surface once again. Roger Lanctot, director of Automotive Connected Mobility at Strategy Analytics, gave a comprehensive overview of the situation, followed by in-depth discussions among representatives from Cisco Systems, NCTA – The Internet & Television Association, the Competitive Enterprise Institute and the OTI.
Cisco's assessment struck a chord with me: “This is one of the oddest issues I have worked on in my 35-year career in public policy,” commented Mary Brown, senior director of Government Affairs at Cisco.
That pretty much sums it up. Brown went on to say that it’s become an increasingly splintered state of affairs, and she counts at least five different splinters. One of them is the notion that DSRC is and should remain the intelligent transportation technology of choice.
The National Highway Traffic Safety Administration (NHTSA) has not mandated DSRC, but if you look at its website, it sure remains a significant part of its efforts, even though the Trump administration has given every indication that it isn’t going to mandate any particular technology. Added to that mixed message is the IEEE recently approved a new study group in 802.11 to look at next-gen vehicle communications; DSRC is based on 802.11p, and they’re looking at enhancements to the standard just as the cellular community has accused DSRC of being old and staid with no path forward.
Also approved today by IEEE 802 is a new study group in 802.11 looking at next-gen vehicle communications. 802.11p (DSRC) seen as "matured." 802.11 enhancements since .11p can do better. More in this PowerPoint: https://t.co/za1mo7c5EP— Steve Crowley (@StevenJCrowley) March 9, 2018
State highway transportation departments continue to move forward with their DSRC deployments and arguments are still being made at the FCC for protecting all seven channels of 5.9 GHz spectrum for the auto industry, rather than opening it up to sharing in the upper part of the band. All of which is to say, DSRC is not dead.
C-V2X would use the same spectrum as DSRC, but it’s not interoperable, and that poses a lot of problems. It’s not much use if General Motors’ Cadillacs are equipped with DSRC (the only ones on the U.S. market that currently are, by the way) but they can only talk to other Cadillacs with the same technology in order to only avoid collisions. Ditto for Ford: If its future cars are C-V2X and they can only talk to one another and no one else, that’s a problem. Same with infrastructure: Who’s going to talk to the traffic lights, DSRC or C-V2X?
Qualcomm and Ford signaled earlier this year that they're making renewed efforts to lobby hard for the C-V2X path, which is significant because Qualcomm in the past has played in both the DSRC and C-V2X camps—and it’s settled with both feet firmly planted in C-V2X. Ford was one of the early proponents of DSRC, but it has pivoted to C-V2X, and the expectation is—or the hope, whichever you prefer—is that other automakers will follow Ford’s lead even before anyone starts talking about a government mandate.
But since the Trump administration doesn’t appear inclined toward a mandate and nobody really has time to wait for a new administration, time is of the essence. People need to get moving in one direction or another if radio technology is going to be part of this whole connected/autonomous car thing.
When I spoke with Qualcomm’s Automotive SVP and GM Patrick Little earlier this year, he was optimistic for C-V2X mandates, including in the U.S., and said Qualcomm shares a passion for C-V2X with Ford. The two are conducting C-V2X field trials in San Diego and Detroit, the results of which hopefully they will share with the public.
All the while, the tech industry is going wild in its development of autonomous cars, and they don’t seem to be too hung up about the debate between cellular and DSRC. Yet the cellular industry is working on autonomous driving in 5G, and any radio technology presumably would augment autonomous cars being developed now.
Just last week, 5G Americas released a white paper examining C-V2X on the way to 5G and asserted how DSRC has several weaknesses, one of which is said to be an inability to meet the higher bandwidth demands of applications like autonomous driving. Then there's Multi-access Edge Computing (MEC) and NFV, which also support V2X communications, with some industry sources saying they don’t think we can even get to real 5G without NFV and edge computing, which makes sense: Doing network slicing, for example, would be cost prohibitive without virtualization and edge computing.
But Wi-Fi is going to be part of 5G as well, something that often gets lost in the shuffle. Unfortunately, the 5.9 GHz space has become so sad that Cisco is now focusing on 6 GHz. “It is painful to watch” the 5.9 proceeding and activities not advance as quickly as one would like, Cisco’s Brown said. The spectrum is just sitting there largely unused.
Cisco had a proposal some years ago to try to share with DSRC when it was the only horse in the race, but now it’s not at all clear what’s going to happen. “At least at Cisco, we are spending far more of our time, energy and mindshare on opening up spectrum at 6 GHz,” because there appears to be no resolution for 5.9 GHz, she said. “There just doesn’t seem to be any way to move that forward.”
NCTA’s Danielle Pineres said 6 GHz is of interest to the association, but it’s hopeful that something will happen at 5.9 GHz because it’s still the best long-term option.
One thing is for sure: Like everybody else, Wi-Fi needs more spectrum. OTI’s Michael Calabrese noted that roughly 80% of mobile device data traffic is using Wi-Fi, so it’s actually vitally important to wireless carriers even if we don’t hear that recognized so much.
Bottom line: The 5.9 GHz space remains a mess, but it’s the FCC’s job to make decisions about spectrum, and it needs to make it a priority. It may not be in charge of transportation safety—that’s for the DOT—but it has a role to play in spectrum policy, and something’s got to give here. – Monica | @fiercewrlsstech | @malleven33