Design Principles for Emerging Multi-Cluster Automotive Networks

In this paper we investigate the consequences of cross network data dependency in multi-cluster automotive networks and propose a concept for breaking the time coupling between networks in order to manage the complexity and facilitate a divide-and-conquer approach. We will show that by increasing the frequency of the data exchange the need for tight time coupling across network boundaries is removed and so-called phase insensitivity is achieved. If the interaction between any two functions is phase insensitive, then the functions can be scheduled in both ECUs without needing to take phase alignment of the schedule within each ECU into account, which reduces the complexity of managing cross-network data exchange. The paper contains the derivation of the condition for phase insensitivity and a discussion of its applicability to automotive multi-cluster networks along with an analysis of the advantages and shortcomings of the phase insensitive approach as opposed to phase alignment, with a particular focus on FlexRay.