Energy-efficient Scheduling Algorithm Based On Aggregation Granularity Control In Wireless Sensor Networks

Wireless sensor networks (WSN) is composed of a large number of micro sensor nodes which are low-power and low-cost With the rapid development of micro-electro, sensing technology and wireless communication, ensure a wide range of applications for WSN in the fields such as agricultures, military, environment, industry control and so on. Compared with traditional wireless networks, WSN is a novel model network and typically characterized by infrastructure less, self-organizing, dynamic topology, wireless channels with limited bandwidth and nodes' limited capability. To be adapted to these special network characters, the corresponding protocols must be designed. The sensor nodes have very limited energy, so the energy consuming is a hot problem in the research of WSN.MAC protocol tries to ensure that no two nodes are interfering with each other's transmissions, and deals with the situation when they do; every shared wireless communication channel. MAC protocol energy-efficiency directly affects the lifetime of WSN. The most important aim of designing MAC protocol is to reduce the energy dissipated in the network and to maximum the network lifetime. The are some of factors that affect the energy consumption of MAC protocol of WSN such as idle-listening,overhearing,wireless channel conflict and so on.To improve the energy-efficiency of MAC protocol, we proposed an Energy-efficient scheduling algorithm based on aggregation granularity control for WSN MAC protocol (ESAAC). The algorithm has two function modules: The data optimizing union EACA and the scheduling union. EACA adopt Application-Independent Data Aggregation (AIDA) schemes, using an efficient aggregation granularity control mechanism to fall off MAC layer data and then reduced energy consume. In scheduling union, network is cluster-based, cluster heads adjust the time-slot of member-nodes according to their weighted communication load in a proper order and frequency. Use this Structure we can control the overhearing,wireless channel conflict in networks and reduce the idle listening.Simulation results show that the algorithm ESAAC improves the energy efficiency of MAC protocol, and prolongs the lifetime of the WSN. At the same time, algorithm has lower date latency and a lower packet drop rate.