Power-Saving and Fault-Tolerance in Real-Time Embedded Mobile Systems: The Trade-Off Point

SANTOS VALENTINUZZI, RODRIGO; JORGE SANTOS; JAVIER OROZCO,

Santiago de Chile

Workshop; Workshop on wireless communications and information technology in developing countries; 2006

IFIP

In this paper a method with the double purpose of reducing the consumption of energy and giving a deterministic guarantee on the fault tolerance of real-time embedded mobile systems operating under the Rate Monotonic discipline is presented. A lower bound exists on the slack left free by the tasks executing at their worst-case execution time. This  deterministic slack can be redistributed by a proper scheduling and used for either of the two purposes. The designer can set the trade-off point between them. A static redistribution to save energy leads to a single operating frequency whereas a dynamic redistribution leads to multiple operating frequencies. In addition, more slack can be reclaimed when tasks execute in less than their worst-case time.