Research On Collaborative Task Allocation Mechanism For Wireless Sensor Networks

Wireless sensor networks(WSNs) is a massive and non-central ad hoc network, the energy resource, storage capacity and processing capability of every single node is highly limited. In order to deal with the contradiction between constrained resource of single node and demand of network application, a collaborative task allocation mechanism based on dynamic alliance is proposed.At first, a network architecture based on multi-agent stystem is established, and then a collaborative task assignment mechanism based on dynamic alliance is proposed. In this mechanism, the information stored by the chief node and the others is updated dynamically, and a task immigration program dealing with single node failure is presented. The alliance is established when tasks are coming and disolved after tasks are finished. The mechanism can be applied to dynamic network and has self-maintenance in some extent at the same time.Then a task allocation algorithm based on discrete particle swarm optimization is proposed, which is the core to achieve the above mechanism. A fitness function based on total completion time and energy consumption of the tasks is established by adaptive weighted method in this algorithm, which is aimed at optimizing the task allocation. Mutation operation is applied to particles when the individual and population diversity of particles are lower than the threshold. The results of the simulation with Matlab show that this task allocation mechanism can reduce network energy consumption significantly, shorten the task execution time and exhibit good performance when the number of tasks or network communications hops is increasing, all of which prolong the life of WSNs.