Practical Experiences on a Communication Middleware for IP-based In-Car Networks

Current in-car communication networks are based on automotive specific technologies like CAN, FlexRay and MOST and use proprietary communication protocols. While CAN and FlexRay come with a signal-based communication paradigm, MOST provides a more sophisticated interface based on ``function blocks'' to the application programmer. In the next years, we expect IP-based protocols and standard technologies like Ethernet to be deployed for more and more in-car communication tasks. As a result, we need an IP-based communication middleware that provides both signal- and function-based interaction paradigms and works for all distributed applications in vehicles. Main challenges are the large variety of embedded devices and operating systems used in a single car in terms of footprint and compute power. Furthermore, it must be possible to migrate existing interface definitions from legacy technologies to the new IP-based solution. In this paper, we propose an IP-based in-car middleware framework based on an open source solution, Apache Etch. We sketch how different, yet interoperable versions of the middleware can be used to construct a scalable system that fits to both small and large devices. Finally, we identify extensions to Etch that are necessary to qualify the solution for the use in the automotive domain.