E-TOLL/DSRC STANDARDS: USDOT talks of going it alone on data link

USDOT is unhappy with the data link (Layer 2) part of the proposed ASTMv7 and may break with the collaborative standards setting process that has been under way for several years to try and develop a next generation standard for the vehicle-roadside radio communications in North America.

Bill Jones who works the vehicle-to-roadside or Dedicated Short Range Communications (DSRC) standards issue at the Joint Program Office for ITS at USDOT told us: “The whole of Layer Two (in the draft) is a major problem. It is not clear we will get agreement on a standard (for Layer Two), and even if we do, we don’t think any manufacturer is going to build to it. Our view is that there is simply not going to be a viable (Layer Two) standard in the forseeable future. We can’t wait around any longer.”

Jones told us that he disagrees with the department’s standards building consultant Lee Armstrong over the viability of Layer Two. “Obviously we have a disagreement,” he said matter of factly.

The new USDOT hardline emerges from two days of meetings with the major manufacturers at the end of July. Christine Johnson head of the Joint Program Office led the meetings, with Bill Jones as a forceful number two. The three major manufactuers Mark IV, Raytheon and Amtech all said they could not see themselves building equipment to the new standard if it provided for both data link formats as in the proposed Layer 2. Raytheon stressed that the equipment would be compromised in its capability. Amtech was strongest in saying that it would be too complex to produce at an attractive price. Mark IV said they couldn’t see a market, and that their existing customers have priority.

Roger O’Connor of Raytheon told USDOT his company was delighted with the agreement on Layer 1 and on the applications handling and that this was major progress on which everyone could build. But, he said, the Layer 2 differences were simply too great to helpfully reconcile in the one standard. Raytheon could not see any market for a transponder which was less capable than any of the existing systems because it attempted to allow room for interoperability of quite different data links. Though their reasoning was different the other manufacturers also concluded that a concensus-made Layer 2 was going to be a poor product with little appeal. None expressed any confidence it would sell or suggested they would build it.

USDOT now has Ray Yuan of the Johns Hopkins University Applied Physics Laboratory working to document an alternative. It seems likely to put the ASTMv6 Layer 2 onto the agreed upon ASTMv7 Layer 1 and the associated IEEE P1455 approach to handling applications. The USDOT plan is to present a documented proposal based on Yuan’s work as a proposed standard at a meeting in December.

“We are obliged by law to set critical standards and there is no doubt whatever that DSRC is critical,” said Jones. “In addition we have to decide on a viable standard for commercial vehicles and border operations in which we are extensively involved. The ASTM Layer 2 is clearly years away — if ever — in terms of equipment. We have to decide what configuration or configurations we’ll specify for ongoing federal programs. We can’t just wait around. We will have a firm proposal (for Layer 2) this year, probably around December.”

Tolling dominant use

As Jones sees it the problem for the new standard is that tolling is the only currently viable industry using DSRC and it seems unlikely anyone will build DSRC equipment specially for non-tolling applications. Around 5 million toll transponders are now in use in the US with 10 million considered likely by 2000 or 2001. Fewer than 100,000 truck transponders are in use with a maxium market 5 to 10 years off of about one million if half the heavy trucks in North America are equipped. There are maybe 10,000 in-vehicle navigation devices, but little else.

“Our judgment is that companies won’t build to it because they don’t see a paying market for it. So we have to decide a standard for our purposes and we propose to do that,” said Jones.

The ASTMv7 physical layer document passed its ballot this summer and the final touches are being put on a revised version that responds to many comments that accompanied the ballots. Some changes have been informally agreed to by all of the writing group members, Armstrong told us.

“This should result in a standard that is ready to publish by the end of the year,” Armstrong said of Layer One.

IEEE

The IEEE P1455 Application Layer of the North American DSRC standard completed a first round of balloting in August and passed. But there were 372 comments received, and under standards developoment rules the writing group has to address these and go to a second ballot with the substantive changes.

Pete Houser of Signal Processing Systems is in charge of the application layer process.

Ron Cunningham at Lockheed Martin told us that the standards making process in North America is “moving in the right direction” and has reduced the extent of incompatibility. But, speaking on similar lines to Jones, he said it isn’t clear that it is going to pay any company to do the expensive work of designing the ASIC needed for a completely new transponder to the new agreed standard.

“You have the problem that you can get something (by way of a standard) that looks reasonably satisfactory on paper. But if you had to make many compromises and accomodate different ideas and interests, you can end up with a whole lot of options. Then it becomes somewhat moot whether the final document really serves as a standard. It can become a bit of a standard without substance.”

Pete Houser agreed it was quite reasonable to worry about writing a standard that wasn’t going to be built or leaving so many options it could be built in incompatible ways.

Meanwhile there are rather few complaints from DSRC system operators in North America about problems of interference between different systems. With the great bulk of vehicles operating within the confines of evolving standards zones, or only harmlessly interacting with incompatible systems, there is little pressure to move decisively toward a single North American standard. There is even less interest on the part of most parties here in the European CEN standard. Many here supported a USDOT commentary — posted on its website mid-summer —which was scathingly critical of the CEN DSRC standard as inadequate in capability, costly to produce to, and having much obscure language. A move to encourage the US to embrace the CEN standard for DSRC announced by several companies two years ago went nowhere.

Interference between Raytheon equipment on trucks and Caltrans-21 toll readers or Amtech gear is presently avoided by the simple expedient of keeping them a decent distance apart (like 1km.) The first place new standard equipment is likely to be deployed is at international river border crossings, where truck and toll DSRC operations are most conveniently conducted together. (Contacts Bill Jones, USDOT JPO 202 366 2128, Peter Houser Signal Processing peter.houser@

sps.globalus.com, Lee Armstrong LRA@tiac.net, Ron Cunningham Lockheed Martin 201 996 7143)