Research Of Energy Consumption In Wireless Sensor Network Based On Divisible Load

A rapid development has been made in the wireless sensor network (WSN) industy according to the the promotion of microelectronic, computer and wireless communication technology. WSN is widely used in military surveillance, environmental monitoring, intelligent transportation and other fields. In these applications, a large number of wireless sensor nodes are randomly deployed in the monitored area. Each node works together with the others to complete the monitoring tasks in a form of self-organization. As the wireless sensor node is limited in energy supply, in order to extend the lifetime of the network, WSN energy consumption research has become one of the hot spots in recent years.Two aspects are focused on in traditional WSN energy research:one is the designing of the network layer routing protocol, and the other is the designing of single node hardware. A variety of new methods have been designed. The impacts of data fusion algorithm in the application layer have also been studied by some academics. However, the load scheduling algorithm in the application layer is more conducive for the overall energy consumption characteristics of WSN. The load scheduling algorithm in the application layer is also more conducive for optimizing the energy consumption of WSN. So, it is a new direction for WSN energy research.The divisible load is a special load, which can be divided into any size, and each of these can be processed independently without a limited process order. It is a new load scheduling theory that appling the divisible load to WSN’s load schedule in the application layer. And some scheduling algorithms have been designed based on the divisible load in resent years. However, the researches in WSN based on divisible load are almost for the minimum time scheduling, which does not consider the energy consumption of WSN. As we all know, minimum energy consumption and energy balance plays a more important role for the lifetime extending of network. So, this article focuses on two energy issues in WSN based on divisible load. One is the minimum energy, and the other is the energy balance. Some load schedule algorithms have been designed to optimize the energy consumption:1. Minimizing energy consumption in divisible load WSN:A simple sequential schedule algorithm (SSSA) and an energy-time tradeoff schedule algorithm (ETTS) have been designed based on the classic divisible load schedule algorithm in star toplogy WSN. SSSA is the minimum energy consumption algorithm among the classic divisible load schedule proved by theory and experiment respectively. The experimental result shows that the two schedule algorithm can reduce the network energy and prolong the network life cycle effectively. And SSSA schedule algorithm should be used when the surviving node number is highly important to network topology, otherwise ETTS schedule algorithm should be used when the energy of initial rounds is cared about. Furthermore, ETTS can reduce the energy consumption further with the increase of the given time.2. Energy balance in divisible load WSN:A load schedule algorithm is designed for energy balance purpose in star topology WSN, which have divisible load and the work model using is simultaneous measurement start but sequential reporting. The load schedule strategy deduced from the algorithm has the property of reducing the standard deviation of the network energy consumption under some constrictions. Simulation results show that the load schedule strategy can reduce the standard deviation of the network energy consumption effectively. What’s more, with the increase of the time given, the standard deviation of the network energy consumption can be reduced accordingly by the schedule algorithm.3. Residual energy balancing in divisible load WSN:Two load schedule algorithms have been designed for the star topology and divisible load wireless sensor network, Residual-Energy-Sorting Schedule(RESS) algorithm and Virtual-Ability-Sorting Schedule (VASS) algorithm. Simulation result shows that RESS and VASS algorithms can both prolong the network lifetime effectively, what’s more, VASS algorithm is more stable than RESS algorithm.Some scheduling algorithms have been designed for every scheduling goal respectively. And the effectiveness of the algorithm is demonstrated by the results of simulation experiments. Experimental results show that, the designed algorithms can improve the lifetime of WSN significantly compared with the typical divisible load scheduling algorithm.