Timing Analysis and Optimization of FlexRay Dynamic Segment

Abstract

FlexRay is a new high bandwidth communication protocol for automotive systems, providing time-triggered transmission of periodic frames in a static segment and priority-based scheduling in a dynamic segment. Analysis techniques are required to compute bounds for the FlexRay frame response times, before the standard is used for safety- and time-critical applications. Moreover, the design of a FlexRay schedule is not an easy task because of protocol constraints and multiple design objectives. In this paper, we first study the problem of timing analysis of frames transmitted in the FlexRay dynamic segment, providing a tight upper bound to the worst case response times. Then, we propose a novel algorithm to assign identifiers (priorities) to frames, to optimize a design objective. We show the results of the application of the method to a vehicle communication system.