Time-Interval Scheduling and its Applications to Real-Time Systems

Many embedded real-time applications have strict time constraints to perform computations and access I/O devices. However, aspects related to real-time scheduling algorithms may interfere with the execution of jobs reducing the benefit of a task. We assume that the execution of a job has a positive benefit if performed inside an ideal time-interval. Operations performed before or after this ideal time-interval are considered worthless to the system. We propose a new task model for dynamic task scheduling where tasks are composed by segments and one of them must execute inside an ideal time-interval. This time-interval represents a valid execution interval and has a QoS function to assign a benefit according to the time the job executes.