MOST: A better automotive infotainment network not invented here

There are many examples, but two will suffice. In the mid-1990s, it was the J1850 standard for multiplexing. The world was moving toward the CAN bus, which originated in Europe. While U.S. auto manufacturers dithered over J1850, the CAN bus became universal.

The same thing is happening now with MOST (Media-Oriented Systems Transport), an automotive infotainment network. MOST also originated in Europe, developed by MOST Cooperation, founded by Audi, BMW, Daimler, Harman/Becker and SMSC. They represent the core partners that now form the MOST steering committee. The MOST Cooperation now includes 16 car makers and 80 suppliers.

Semiconductor manufacturers seem to agree that the adoption of new automotive electronic technology generally begins in Europe, moves to Asia and eventually reaches the U.S.. There is also general agreement that BMW and Mercedes are the earliest adopters among auto manufacturers.

MOST is following this pattern with its European origin. It was used first by Audi, BMW and Daimler and was then adopted by Toyota, Hyundai and other Asian manufacturers. Although several U.S. manufacturers are investigating MOST, the only currently announced application is in a Dodge RAM pickup.

There is some buzz among some U.S. auto manufacturers about using Firewire (IEEE 1394) for automotive infotainment networks. There is an automotive Firewire standard, (IDB-1394 CCP, for Customer Convenience Port), but Firewire is primarily a computer networking standard not originally designed for automotive applications.

IEEE CCP defines the physical layer but lacks the network management layers needed for a full system implementation. Firewire has been widely used by Apple and for digital audio and video connections, but it did not become a de facto computer standard. It has been touted far longer than MOST has been around, but, to date, there is not a single implementation in a production automobile.

MOST was designed from the beginning for use in noisy automotive environments. Its synchronous nature makes it easier to manage the electromagnetic compatibility issues found in cars. It also reduces the overhead needed to transport a given amount of information. This means that it uses almost all of its nominal bandwidth for actual data transfer.

Other networks sometimes can use less than half their nominal data rates for continuous data transfers, such as those needed for A/V streams. The transport capability of MOST 150, the newest version of MOST spec, is comparable to several hundred megabits per second on other networks.

The U.S. is no longer an automotive island. U.S. companies are often technology leaders. They have the engineering talent. But, the time has passed when U.S. auto manufacturers could develop and use only their own standards and ignore the rest of the world.

When technologies as good as MOST come along, it's time to look outward and adopt them. In this way, U.S. can makers can again lead in electronics technology, not lag behind.

About the author: Morry Marshall, vice president of strategic technologies at Semico Research Corp., provides market research on the semiconductor industry with particular emphasis on automotive electronics, MEMS devices and semiconductor packaging.