Startseite > Automotive > Glass Fiber Connectivity for Automotive Networks

MOST Physical Layer

Glass Fiber Connectivity for Automotive Networks

24. Juli 2013, 17:31 Uhr | Andreas Engel and Markus Dittmann

▶ Diesen Artikel anhören

Fortsetzung des Artikels von Teil 1

High data rates are possible

Regarding future applications in the car’s infotainment and driver assist systems, data rates are expected to come into the range of 3 up to 5 Gbit/s. One bandwidth-consuming application is high resolution, low latency video as needed for real time object recognition. Stringent reliability requirements have to be guaranteed over the car’s expected average lifetime of more than 15 years. During that time, the operating environment is anything but pleasant: Vibration, temperatures ranging from –40 up to 105°C while humidity changes from desert dry to foggy. But overall costs for such a robust, reliable high speed data link have to be reasonably low to be acceptable. Besides that, there are additional demanding requirements on the agenda such as light weight and compatibility with cable harness processes and structures.
An optical cable is inherently immune to electro-magnetic interference. Because of this, it is attractive for use in densely packaged, high noise environments like the harness of a car. In comparison to copper based solutions there is no need to shield the cable. So, thinner, lighter and more flexible cables than copper cables are possible for the same application.
The technology used in optical data communication applications is based on 850 nm vertical cavity surface emitting lasers (VCSEL) launched into all glass fibers (AGF) with a graded (refractive) index profile avoiding modal dispersion, as it would ruin the bandwidth in step index fibers like the POF or PCS. This combination allows for data rates >5 Gbit/s over 15 m link length, as currently requested for future cars. These fibers have been used in the data communication industry not only for their high bandwidth on long link length but also for their low power demand and small diameter cable, allowing for better air flow and cooling in the server racks. Server cooling might not be a relevant argument for automotive applications, but light weight, small diameter and bend radius performance will be.
Within TE Connectivity there is profound experience with AGF, VCSEL based transceiver technology to build fiber optic transceivers (FOTs) and connector systems. This provides an ideal portfolio for the development and specification of a reliable future glass fiber based physical layer with adaptations to meet automotive requirements.