Slot multiplexing optimization for minimizing the operating frequency of a FlexRay bus under hard real-time constraints

Industrial applications such as automotive ones require a cheap communication mechanism to send out communication messages from node to node by their deadline time. This paper presents a design paradigm in which we optimize slot multiplexing of a FlexRay bus under hard real-time constraints so that we can minimize the operating frequency of the FlexRay bus. The reduction of the operating frequency of a FlexRay bus helps one to choose a slower and cheaper wire harness for building a distributed system. We formulate a slot multiplexing optimization problem under hard real-time constraints. We build an integer linear programming (ILP) model as a means for solving the slot multiplexing optimization problem. Our experimental results show that our design paradigm achieved a 72.7% smaller operating frequency at its best than the naive one.