MOST Network

MOST is a synchronous network. A timing master supplies the clock with a synchronous and continuous data signal and all other devices synchronize their operation to this base signal. This technology eliminates the need for buffering and sample rate conversion so that very simple and inexpensive devices can be connected and the hardware of the network interface itself is lean and cost effective. The technology is similar to what the public switched telephone network uses. Within the synchronous base data signal, multiple streaming data channels and a control channel are transported. The control channel is used to set up what streaming data channels the sender and receiver are to use. Once the connection is established, data can flow continuously and no further addressing or processing of packet label information is required. The bandwidth of the streaming data channels is always available and reserved for the dedicated stream so there are no interruptions, collisions, or slow-downs in the transport of the data stream. This is the optimum mechanism for delivering streaming data (information that flows continuously) like audio and video. MOST has been designed for high quality of service and cost effective transport of audio and video.

Computer based data, such as Internet traffic or information from a navigation system, is typically sent in short (asynchronous) bursts as packets and is often going to many different places. To accommodate such signals, MOST has defined efficient mechanisms for sending asynchronous, packet based data in addition to the control channel and the streaming data channels. These mechanisms run on top of the permanent synchronous data signal. However, they are completely separate from the control channel and the streaming data channels so that none of them interfere with each other.

In summary, MOST is a multiplex network that has different channels with their own mechanisms to transport all the various signals and data streams that occur in multimedia and infotainment systems. They all run on top of a synchronous base data stream which guarantees high quality of service for the audio and video signals where disturbances are not acceptable.

The key features of the MOST Network are:

Ease of Use

  • simple connectors
  • no hum loops, no radiation
  • Plug-n-Play; self identifying devices with auto initialization
  • dynamically attachable and re-configurable devices
  • virtual network management including channel allocation, system monitoring addressing and power management

Wide Application Range

  • applications with varied bandwidth requirements
  • high degree of data integrity with low jitter
  • support of asynchronous and synchronous data transfer
  • support of multiple masters
  • supports up to 64 devices
  • simultaneous transmission of multiple data streams such as control, packet and real-time information
  • devices can be constructed out of multiple functions
  • low overhead due to embedded network management

Synchronous Bandwidth

  • synchronous channels provide guaranteed bandwidth with no buffering required.

Asynchronous Bandwidth

  • variable asynchronous bandwidth with additional dedicated real-time control channels


  • wide range of real-time channel sizes and packet sizes
  • remote operation and flow control
  • variable asynchronous bandwidth with additional dedicated real-time control channels
  • protocol independent

Synergy with Consumer and PC Industries

  • operates with or without PC
  • consistent with PC streaming

Low Implementation Cost

  • low cost channel to distribute control information without extra wiring
  • zero data overhead to move synchronous data after a connection is established
  • synchronous channels eliminate the need for buffering and sample rate conversion
  • suitable for embedding in consumer devices and peripherals
  • cost-effective electrical and optical solutions
  • inexpensive silicon from many suppliers

Open Systems Interconnect Reference Model