Power-Efficient Software Allocation in Wireless Sensor Networks

The present work concentrates on the formulation of a model and a heuristic for generating, respectively, optimal and sub-optimal software allocations to maximize the lifetime of Wireless Sensor Networks. This is achieved by minimizing and balancing the energy consumption, while preserving the completeness of the application and the resilience against pqfguÓ faults. In the considered scenario a node can schedule and execute multiple functions, either stored on its Flash memory or dynamically retrieved from the base station or the cluster head, through a dynamic reprogramming mechanism. Execution is guaranteed by a distributed scheduling mechanism, capable of orchestrating the execution of a given function among all the nodes on which that function is run, so that its execution frequency is guaranteed and the overall energy consumption minimized by exploiting parallelism among nodes. Both the model and the heuristic include constraints on the available memory and the desired execution frequency of functions, as well as routing and overhearing issues. The main result of the proposed work is a framework to efficiently define the software allocation on a WSN under power-consumption constraints, encompassing also more evolved architectures, equipped with a dynamic reprogramming mechanism, multitasking nodes and a distributed scheduler