MOST - The High-Speed Multimedia Network Technology
Multimedia Bus for Transmitting Audio, Video and Control Data

Know-How & Solutions for MOST

MOST ® (Media Oriented System Transport) is a serial communication system for transmitting audio, video and control data via fiber-optic cables. This multifunctional, high-performance multimedia network technology based on synchronous data communication requires professional software tools and hardware interfaces.


  • Sophisticated products by years of experience in the automotive networking industry



Media Oriented Systems Transport (MOST)

The MOST specification not only defines the Physical Layer and Data Link Layer; it covers all seven layers of the ISO/OSI Reference Model for data communication. Uniform interfaces simplify implementation of the MOST protocol in multimedia devices. For the application developer MOST serves primarily as a protocol definition. The user gets a uniform object-oriented interface (Application Programmer Interface - API) which allows device functionality to be utilized.

Communication functionality is provided by MOST System Services: Low-Level System Services, Basic-Layer System Services and the Application Socket. Low-Level System Services (Layer 2 services) are implemented in a MOST transceiver and are based on the Physical Layer. Wrapped between the MOST transceiver and the API (Layer 7) are the MOST NetServices, consisting of the Basic-Layer System Services (Layers 3,4,5) and the Application Socket (Layer 6), the MOST protocol.

A MOST network, usually laid out as a ring, may include up to 64 MOST devices. Due to its plug&play functionality it is not very difficult to either add or remove a MOST device. Given suitable topological conditions stars may also be laid out - and double rings may be used for safety critical applications.

In a MOST network one MOST device handles the role of the Timing Master which continuously feeds MOST frames into the ring. The preamble sent out at the beginning of the transmission of a MOST frame allows the Timing Slaves to synchronize. The Timing Slaves can continuously resynchronize themselves to the biphase coding that underlies the synchronous transmission.

In total the bandwidth available for the transmission of streaming data (synchronous data transmission) and packet data (asynchronous data transmission) is approx. 150MBaud.

MOST supports uncompressed stereo audio channels in CD quality, as well as multi-channel audio streams or video transport streams.

Simultaneously MOST offers a channel for transmitting control messages. These control messages can be used to configure MOST devices as well as the synchronous and asynchronous data transmission. MOST is also able to tunnel Ethernet communication through a dedicated channel.

Vector´s MOST Contribution

Vector became an associated member of the MOST Cooperation in 1999.  These fully developed products will support you in your projects: 


Application Product
Analysis software tool for MOST ECUs and networks  CANalyzer .MOST
Development and testing software tool for MOST ECUs and networks CANoe .MOST
MOST interface (MOST150) for USB with access to all data of the MOST ring VN2640
Software for re-programming of MOST ECUs
Flash Bootloader



Here you will find all downloads for our software and hardware products that support MOST: