QoS-aware data reporting control in cluster-based wireless sensor networks

In this paper, we present an efficient data reporting control scheme in a cluster-based hierarchical wireless sensor network, which has two components: (i) intra-cluster data reporting control (IntraDRC) scheme and (ii) inter-cluster control (InterDRC) scheme. The IntraDRC scheme controls the amount of traffic generated in a cluster by selecting a certain number of data reporting nodes based on the desired throughput specified by the end system. On the other hand, the InterDRC scheme offers differentiated reporting paths from a cluster to a sink based on the traffic characteristics. InterDRC considers two parameters: one is the hop counts to a sink to deal with the end-to-end delay constraint while the other is the amount of traffic, generated in a cluster and forwarded from its adjacent clusters, to deal with energy consumption. The proposed scheme applies the block design concept from Combinatorial theory to design a novel data reporting node selection approach. IntraDRC employs the node sets created by block designs as the initial reporting schedule. This schedule can be updated by the request of a reporting node when its queue size approaches a predefined threshold. We consider two network models in the paper. The first model considers homogeneous networks in which every node has the same capabilities and adjacent cluster heads are connected in a multi-hop manner. The second model considers heterogeneous networks in which the cluster heads have high capabilities in terms of processing power and transmission range to directly reach adjacent cluster heads in a single-hop manner. Simulation results show that our scheme achieves good throughput performance while providing stable data reporting that is independent of the network density. The scheme also allows for energy savings by using load balanced data reporting paths.