Introduction to MOST Protocol:
The Automotive industry can look back on the early 20 years of experience using in-vehicle communication systems. The development started with the CAN bus, which has been used in production vehicles since the 1990s. The infotainment module in cars has been developed rapidly in a few years. Where an AM/FM tuner was sufficient, but now many high-end vehicles are now equipped with high-grade sound and navigation systems. There are a lot of protocols in the embedded industry for audio and video interface, but it is not networking based and low speed. So to improve this the automotive industry designed MOST protocol.
This also increases the number of devices involved – radio, cell phone, CD Changer, a navigation system, voice operation, and an additional multi-channel amplifier supplement the primary systems. These devices must interact in concert with each other and can only be controlled via a central operating surface to ensure that the drivers are not distracted unnecessarily. So if you are thinking to use the CAN protocol for an interface, then the bandwidth of CAN bus which can only move the control signals, but can’t communicate the audio/video signals.
To prevent these limitations, MOST (Media Oriented System Transport) communication protocol has been developed with a new & flexible architecture. The MOST Cooperation was founded as a German civil Law partnership (GbR) in 1998 by BMW, Daimler Benz, Becker, and OASIS silicon systems. Thereafter the Audi also joined the group. It since has expanded to include 16 automakers and more than 70 suppliers.
The MOST serial bus uses a daisy-chain or ring configuration to distribute audio, video, voice, and data signals. These signals can travel on fiber-optic circuits or by wire. Right now, the MOST system can handle up to 65 devices in the typical daisy chain configuration. None of the manufacturers have that many systems and modules on their MOST protocol communication lines as of yet, so there’s plenty of room for growth and additional systems.
What is MOST Protocol?
The MOST (Media Oriented Systems Transport) is a high-speed multimedia network technology serial bus-based daisy-chain topology or ring topology and synchronous data communication protocol to transport the audio, video, voice and data signals via plastic optical fiber (POF) (MOST25, MOST150) or electrical conductor (MOST50, MOST150) physical layers.