MOST Physical Layer Glass Fiber Connectivity for Automotive Networks

The MOST Cooperation is requesting a physical layer with a data rate capacity of 3 to 5 Gbit/s for the next generation.
The MOST Cooperation is requesting a physical layer with a data rate capacity of 3 to 5 Gbit/s for the next generation.

In 2001, the very first car implemented MOST. Since the introduction, more than a hundred vehicle models by several car manufacturers have used this technology for automotive network applications. At these times, the physical layer was started based on plastic optical fiber (POF) with a data rate of 25 Mbit/s. Now, the MOST Cooperation is requesting a physical layer with a data rate capacity of 3 to 5 Gbit/s for the next generation.

t the very first beginning, the physical layer was started with a data rate of 25 Mbit/s. It was enhanced to 50 Mbit/s over unshielded twisted pair (UTP) and later to 150 Mbit/s over coax and POF cables. But, that is not enough. Following the needs of several future use cases in the area of automotive infotainment and driver assistance systems, the MOST Cooperation is requesting a physical layer with a data rate capacity of 3 to 5 Gbit/s for the next generation. At these requested data rates, all glass fiber (AGF) based optical transmission has become attractive, because of its well-known and successful history in the data communication world. Even for consumer IT applications like USB 3.0, optical solutions become apparent. So, the optoelectronic technology has been already in existence and there will be an attractive solution for the upcoming bandwidth need on the horizon – with some adaptations to the automotive requirements on the packaging, cable and connector.
At the beginning of the 1990s, TE Connectivity (TE) started under the brand AMP to investigate the performance of plastic optical fibers and connectors in regards to automotive requirements. In particular, the harsh and severe environment conditions in the vehicle were tested and examined. Besides the temperature, humidity, vibration and mechanical stress, the impact of severe contamination with oil, sealing gel, dust and several chemical substances were also investigated. From the very first beginning, a major challenge was to adopt the optical technology, which was originally developed for telecommunication applications, to the requirements of the automotive industry. The first milestone for the optical physical layer was achieved with the successful implementation of the D2B infotainment network at Daimler AG in 1998. With the launch of the optical MOST networks in 2001, more and more cost efficient, fully automatic processes for pigtail assembly and for fiber termination have been established. The knowledge and experience gathered was a good base to examine future needs for the optical physical layer for automotive applications based on glass optical fiber.