Traffic Transfer Assisted by Super Nodes for Strip-Shaped Wireless Sensor Networks

In wireless sensor networks (WSNs), the imbalanced energy consumption in data transmission may cause energy holes around the sink, which dramatically shortens the network lifespan. Current solutions have two limitations: one is the inevitable traffic gathered around the sink, and the other is the overly ideal network model, e.g., the square region or circular area. In this article, we focus on strip-shaped networks and propose a novel data transmission scheme, which employs a few super nodes near the sink to take traffic load. Due to the high energy capacities and communication abilities, super nodes transfer a part of the data of the network and send it to the sink directly. The entire network is partitioned into multiple clusters, and super nodes are placed in a specific cluster. We discover that the greatest effect on the network lifetime is the energy consumption of two clusters: 1) the cluster nearest to the sink and 2) the upstream cluster nearest to the super nodes. To improve the system longevity, we make the two clusters have equal energy dissipation, and thus obtain the optimal location of super nodes. Some simulations are carried out to verify the reasonability of the results and exhibit the advantage of our scheme in terms of network lifetime.