α-Fraction First Strategy for Hierarchical Model in Wireless Sensor Networks

Energy hole refers to the critical issue near the sinks for data collecting, this problem effects the lifetime of wireless sensor network to a great extent. Frequently data forwarding from distributed sensors to the sink will speed up the energy consumption of the sensors near the sink. This circumstance shortens the lifetime of the sensor network. In this paper, an α-fraction first strategy was proposed to build a hierarchical model of wireless sensor networks that concerning the energy consumption. The model mixes the so-called relay nodes into the network for transmitting and collecting data from the other sensor nodes. We studied the Farthest First traversal and Harel methods, then combined the proposed α-fraction first strategy with the two methods respectively. Three algorithms of FF+Fr(α), HD+Fr(α), and HL+Fr(α) were designed for determining the relay nodes in sensor networks. The algorithms can be used to construct a two-tier sensor network with fewer relay nodes than the results of the Farthest First traversal and Harel methods. The proposed strategy also could be used with any other algorithms that regarding for choosing one of many options. The simulation results show that our proposed algorithms perform well. Thus, the network lifetime can be prolonged.