Towards a layered architecture for the Flexible Time-Triggered Replicated Star for Ethernet

Distributed embedded systems (DES) have traditionally been designed assuming that the requirements they need to satisfy are known in advance. If this is not the case, and a DES should operate autonomously without interruption, it needs to be adaptive. For this, flexible approaches are necessary and this applies in particular to the network of the DES. However, if the probability of faults occurring is non-negligible, then flexibility alone is not enough and fault tolerance is also necessary. The Flexible Time-Triggered Replicated Star for Ethernet (FTTRS) is a set of protocols and mechanisms together with a specific network topology that builds on a switched-Ethernet implementation of the Flexible Time-Triggered (FTT) communication paradigm by enhancing it to not only provide flexibility, but also fault tolerance. This paper describes our efforts towards a layered architecture for FTTRS to benefit from the well-known advantages of these architectures, such as making the complexity manageable and easier to communicate, and making the design more future proof by allowing changes in one layer without affecting other layers.