AMIC has met with representatives from the 1394 Trade Association and the IDB Forum in an effort to hammer out a specification that would put IEEE 1394 serial buses on board everyday vehicles. If they can reach agreement, the bus would provide a high-speed connection for the efficient transmission of data in vehicles. The agreement would also enable consumers to plug handheld electronic devices, such as camcorders and DVD players, into vehicle networks.

The availability of such bus technology is considered critical because of the increasing amount of digital data that now passes through vehicles. In particular, automotive audio and video systems will require high-bandwidth buses to handle huge data streams in the future.

The 1394 serial interconnection is said to be a strong candidate for such applications because of its high speed and compatibility with consumer electronics. IEEE 1394 is already used in more than 10 million camcorders and eight million PCs, as well as in millions of printers, scanners, video games, and mass-storage devices. It offers speeds of 100, 200, and 400 Mbits/second.

"One of the big things driving 1394 is that it does very well with video," said Arlan Stehney, executive director of the IDB Forum (Pittsburgh), a cross-industry group concerned with networking and electronics standards. "So it's well-suited for rear-seat entertainment systems in minivans and sport utility vehicles."

The meeting between AMIC and the standards groups raises questions about the future of automotive network buses. AMIC is currently drafting the first release of a specification that will include a low-speed CAN (controller-area network) bus, and possibly a high-speed fiber optic bus. Until recently, the fiber-optic Media Oriented Systems Transport (Most) bus was the leading high-speed candidate for endorsement by AMIC.

But OEM engineers and representatives from the 1394 Trade Association and the IDB Forum this week introduced an 80-page draft spec of the so-called IDB-1394 bus, which could be thrust into a prominent position with AMIC.

The AMIC's endorsement could be critical for the technology, because AMIC counts as members BMW, DaimlerChrysler, Ford, Fiat, General Motors, Honda, Mitsubishi, Nissan, PSA Peugeot-Citroen, Renault, Toyota and Volkswagen. The group of manufacturers has stated that it wants to standardize electrical architectures because such architectures could lead to simpler implementation of navigation systems, CD players, video screens, digital radios, cell phones, and a host of other devices in their vehicles. Car manufacturers now complain that they must often reengineer vendor products, which are not designed to any specific standard. As a result, they lose valuable development time and risk falling behind the rate of innovation in the electronics industry.

IDB-1394 could help by offering car makers a high-speed fiber optic bus that takes advantage of widely used technology. "The idea is to leverage the economies of scale that you get from 1394 technology and incorporate them into automotive applications," said Frank Desjarlais, a network systems engineer for Ford Motor Co. who wrote the draft IDB-1394 specification along with Brad Little, an engineer with Texas Instruments Inc.

The new specification describes the basic architecture, plastic fiber and copper connector specifications for the 1394 multimedia backbone. It provides consumers with a foundation for 1394-equipped embedded devices and provides a way to connect portable computer products such as CD players, DVDs, games or laptop computers in a vehicle.

The spec also includes a so-called "Customer Convenience Port" to make a connection to those outside devices. The convenience port, which uses copper wire, provides a common type of port that consumer devices can plug in to. Embedded 1394 dashboard devices, however, would connect directly to the bus.

Eight months in the making, the IDB-1394 spec was fashioned with input from Ford, General Motors and Toyota, as well as from makers of consumer devices such as Sony and Panasonic. "There's been agreement between the auto manufacturers and the consumer electronics giants that it's in their best interest to work together on this," said Max Bassler of Molex Inc. (Lisle, Ill.), vice chairman of the 1394 Trade Association. "They want to leverage 1394 technology."

Whether IDB-1394 will be endorsed in the AMIC specification is still open to question. AMIC board members said that technical issues must first be resolved before IDB-1394 can be endorsed. In particular, engineers question whether IDB-1394 meets the electromagnetic interference capabilities needed for an automotive environment, and whether it will meet temperature specs.

AMIC members know, however, that they will need a high-speed bus specification at some point in the near future. The only bus set for definite endorsement by AMIC right now is IDB-C, which offers a speed of 250 kbits/s. In contrast, the Most system features a speed of 24.8 Mbits/s, while IDB-1394 operates at 100 Mbits/s or greater.

Neither Most nor IDB-1394, however, appear likely to make the first release of the AMIC spec. Most, which was co-developed by Oasis Silicon Systems AG (Karlsruhe, Germany), Becker Automotive Systems (Karlsbad, Germany), BMW and DaimlerChrysler, has been stalled in the AMIC proceedings by intellectual property issues. AMIC members say those issues, which involve "lack of openness," must be resolved before they can endorse it. For that reason, along with IDB-1394's technical problems, they question whether either high-speed bus can be endorsed in their first release specification, due out in October. "Given the timing, the reality is that we probably won't endorse either of them just yet," said Scott Andrews, a former Toyota engineer who cofounded AMIC.

But AMIC member companies said they have no preconceived notions about how many high-speed buses AMIC can endorse. "It's not a requirement that we endorse any high-speed bus in release one," said Mike Noblett, an engineering manager for General Motors and a program manager for AMIC. "Nor is it a problem if we endorse two of them."