Section: New Results

Lopht back-end for TTEthernet-based distributed systems

Participants : Raul Gorcitz, Dumitru Potop-Butucaru.

The global objective of this activity is a large-scale, ongoing effort to assess the possibility of automatically synthesizing full real-time implementations, including the so-called "bus frame" (the network configuration) on complex industrial platforms and for complex functional and non-functional specifications. We worked this year in the context of the post-doctoral position of Raul Gorcitz, funded by the ITEA3 ASSUME project, but also in the framework of our collaboration with CNES and Airbus DS.

The chosen platform was an industry-level evaluation platform using several Single-Board Computers (SBCs) running the VxWorks 653 OS, and connected through a Time-Triggered Ethernet (TTE) network. This platform was provided by CNES, as typical target for embedded applications. TTE is a standardized commmercial communication network, on top of a switched Ethernet basis, ommmercialized by TTTech. TTE adds support for realtime and fault tolerant communications, allows multiple communications of mixed criticalities to share a single physical medium. This is ensured by means of dedicated hardware using a set of configuration files describing the system architecture and behavior. These configurations are synthesized by the proprietary TTEplan tool starting from a global network description file.

The main scientific difficulty was the formal modeling of the behavior of the TTE network, followed by the extension of scheduling algorithms to consider such a network. While preliminary results were obtained and published last year, we completed and demonstrated this work to our industrial partners, and we are currently writing a second paper on the subject.