Optimal scheduling of switched FlexRay networks

This paper introduces the concept of switched FlexRay networks and proposes two algorithms to schedule data communication for this new type of network. Switched FlexRay networks use an intelligent star coupler, called a switch, to temporarily decouple network branches, thereby increasing the effective network bandwidth. Although scheduling for basic FlexRay networks is not new, prior work in this domain does not utilize the branch parallelism that is available when a FlexRay switch is used. In addition to the novel exploitation of branch parallelism, the scheduling algorithms proposed in this paper also support all slot multiplexing options as defined in the FlexRay v 3.0 protocol specification. This includes support for the newly added repetition rates and support for multiplexing frames from different sending nodes in the same slot. Our first algorithm quickly produces a schedule given the communication requirements, network topology and FlexRay parameters, but cannot guarantee an optimal schedule in terms of the bandwidth efficiency and extensibility. Therefore, a second, branch-and-price algorithm is introduced that does find optimal schedules.