An Energy-Balanced Algorithm For Multiple Mobile Sinks In Wireless Sensor Networks

Wireless Sensor Networks(WSNs), as key technology of Data collecting, have been the focus of people’s attention. Traditional WSNs are composed entirely of static nodes. The pattern of multi-hop data uploading lead to faster energy consumption of the nodes near Sink nodes. The networks may produce energy holes. To solve this problem, the researchers introduced the concept of mobile sensors which can balance the energy consumption of the networks. Based on the better perception and processing capacity, they can collected data efficiently. Since the mobile sensors moving back and forth in the monitored area, energy consumption is large, and it is difficult to replenish energy, which make restricted use of mobile sensors application. How to save energy and extend the life cycle of a network become the hot research of mobile sensors. Based on the multiple mobile sinks in WSNs, this paper proposed an energy-balancing algorithm, which purpose is to extend the network life cycle.In this paper, the monitoring area is divided into some sub-areas, each sink node is responsible for the data collection in each sub-areas. We reference to the energy consumption of data-collecting and moving of mobile sink to balance the energy consumption of many sinks. The algorithm includes three processes:(1) Divide the network into a number of equal-sized hexagonal grids, the grid side is equal to the static Sensor transmission radius, and the center point of each grid act as the stop point for mobile Sink collecting Data.(2) Divide the network into some sub-partitions according to the data-collecting energy consumption of sink. The number of sub-partitions is same as the number of mobile sinks. Hence, the collecting-data energy consumption is almost the same in each sub-partition.(3) Adjusted sub-partitions according to the energy consumption of mobile sink movement. Mobile strategy is proposed to reduce the movement times of sinks to traverse the partition and to reduce the unnecessary movement of sinks.In this paper, some experiments have been performed for evaluating the effectiveness of key processes in our energy-balanced algorithm which based on Java language. The experiments show that the algorithm can reduce the energy consumption difference of each mobile sink, so that the energy of each sink has been fully utilized, it will help to extend the network life cycle. In addition, the sub-partitions become tidy with the use of grid mobile strategy, this is helpful to reduce the steps of sink mobile and save energy. Experiments comparing the sink energy consumption values between hexagon division and quadrilateral division, the results show that when using hexagon divided network the energy consumption of sink will be less. And the larger monitoring area, the more energy saving. It is also conducive to extend the network life cycle.