MOST: A Better Automotive Infotainment Network Not Invented Here

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Picking on US automakers today seems like piling on, but I have a beef.  Why do US companies always seem to be the last companies in the world to adopt new automotive electronic technologies?  There are many examples, but two will suffice.  In the mid nineties it was J1850 for multiplexing.  The world was moving toward the CAN bus, which originated in Europe.  While US auto manufacturers dithered over J1850, the CAN bus became universal.  Today, it is MOST (Media Oriented Systems Transport), an automotive infotainment network.  MOST also originated in Europe, developed by the  MOST Cooperation, which was founded by Audi, BMW, Daimler, Harman/Becker and SMSC, 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 finally reaches the United States.  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 picked up by Toyota, Hyundai and other Asian manufacturers.  Although several US manufacturers are investigating MOST, the only currently announced application is in a Dodge RAM pickup.   

There is a buzz among some US auto manufacturers about using Firewire (IEE 1394) for automotive infotainment networks.  There is an automotive Firewire standard, (IDB-1394 CCP (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 never became a defacto computer standard. It has been touted for 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 operation 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, is comparable to several hundred Mbps on other networks.   

The US is no longer an automotive island.  US companies are often technology leaders.  They have the engineering talent.  But, the time has passed when US auto manufacturers could develop and use only their own standards and ignore the rest of the world.  When standards as good as MOST come along, it’s time to look outward and adopt them to lead in electronic technology rather than lag. 

Morry Marshall
Director - Strategic Technologies
Semico Research Corp.
602-788-6553