Energy efficient assignment of events in wireless sensor and mobile actor networks

In this work, we address the problem of optimal assignment of mobile actors in Wireless Sensor and Actor Networks (WSANs) to the places of events in real-time with energy and resource constraints. Given the location information about the actors and the places of events, finding the optimal assignment of actors towards the events with the objective of minimizing the overall movement of actors can be shown to be NP-complete. We formulate the problem of assigning the events to the actors in real-time with resource constraints as Mixed Integer Non-Linear Program (MINLP). We also propose inter and intra zone based localized heuristics for finding the near optimal schedule of the actors to the appropriate events. From the simulations, we observed that the combination of the heuristics, "move to the Earliest Deadline First" (EDF) and "assign the tasks to the nearest actor" performs fairly better than others by minimizing the overall movement required by the actors and reducing the deadline miss ratio. The simulation of inter-zone deadline based heuristic gives results as close as 7% to the objective value obtained by the MINLP problem. © 2006 IEEE.