Most (Media Oriented Systems Transport): A Comprehensive Analysis of the Automotive Multimedia Networking Protocol

The proliferation of sophisticated infotainment and driver assistance systems within modern vehicles necessitates robust highbandwidth in-vehicle networking (IVN) solutions. MOST (Media Oriented Systems Transport) emerged as a dedicated serial communication standard, specifically optimized by the automotive industry to handle the demanding requirements of multimedia data streams. This paper provides a comprehensive analysis of the MOST protocol, detailing its architecture, protocol stack, network topologies (primarily ring and daisy-chain), and physical layer options, including Plastic Optical Fiber (POF) and electrical conductors (Unshielded Twisted Pair - UTP). It examines the evolution of the standard through its key generations: MOST25, MOST50, and MOST150, highlighting the progressive increases in bandwidth and functionality, including the integration of an Ethernet channel in MOST150. The paper discusses MOST's synchronous, time-division multiplexing approach for transporting audio, video, voice, and packet data, contrasting it with other automotive networking protocols like CAN, LIN, FlexRay, and the increasingly prevalent Automotive Ethernet. The role of the MOST Cooperation in standardization and the protocol's widespread adoption by major automotive manufacturers are also addressed. While MOST significantly advanced automotive multimedia networking, its future role is considered in light of emerging technologies like Automotive Ethernet.