Constraint programming approaches to joint routing and scheduling in time-sensitive networks

The deterministic behavior of real-time communication networks is achieved by time-triggered periodic schedules for critical data traffic. Calculating such a schedule requires satisfying a lot of constraints, which in practice may be difficult due to the increasing number of data flows in the network. In the current approaches, the routes of flows are usually given or determined separately from the scheduling process. If the routes of flows can be computed jointly with scheduling, more flows could be scheduled since the algorithm chooses among alternative paths. This paper formalizes the problem of joint routing and scheduling of time-triggered periodic communication in Time-Sensitive Networks, guaranteeing the required deterministic nature of the communication, and proposes two models in Constraint Programming formalism. We further apply the Logic-Based Benders Decomposition on the proposed models and give an extensive experimental evaluation of our solutions showing that our novel approach that models waiting of frames in queues along with the Logic-Based Benders Decomposition exhibits the best performance and significantly increases the schedulability over the state-of-the-art methods.