Energy-balanced data collection with path-constrained mobile sink in wireless sensor networks

Data collection through the mobile sink in wireless sensor networks (WSNs) is an effective solution to the hotspot or sink-hole problem caused by multi-hop routings using the static sink. However, most of the existing research focuses on energy balance of the global network, but ignores the impact of local energy imbalance on the network lifetime. Therefore, this paper proposes an energy-efficient data collection algorithm to extend the network lifetime by balancing inter-cluster and inner-cluster energy (BIIE). In the proposed BIIE, we design an improved hierarchical clustering algorithm to reduce communication costs. To balance the energy between clusters, we design an efficient mechanism to select the optimal rendezvous node (RN) for each cluster and construct the traveling path of the mobile sink to access all RNs by particle swarm optimization (PSO). To balance the energy of the inner cluster, a local re-clustering mechanism is designed according to the residual energy level of sensor nodes. We also conducted simulation tests which confirm that the proposed BIIE can increase the network lifetime by approximately 46% and shorten the path length of the mobile sink by approximately 7% in comparison with other commonly-used algorithms (i.e., WRP and EAPC).