Power Saving Scheme (PSS) in Clusters of Heterogeneous Wireless Sensor Networks

In this paper, we proposed a Power Saving Scheme (PSS) multi-hop sensor network using partition clusters. It avoids collision and idle listening time of sensor nodes for better overall network life time. The basic sensor nodes are simple and have limited power supplies, whereas the cluster head nodes are much more powerful and have many more power supplies, which organize sensors around them into clusters. Such two-layered heterogeneous sensor networks have better scalability and lower overall cost than homogeneous sensor networks. It is proposed that using polling to collect data from sensors to the cluster head since polling can prolong network life by avoiding collisions and reducing the idle listening time of sensors .The proposal focus on finding energy-efficient and collision-free polling schedules in a multi-hop cluster. To reduce energy consumption in idle listening, a schedule is optimal if it uses the minimum time. It also considers dividing a cluster into sectors and using multiple non overlapping frequency channels to further reduce the idle listening time of sensor. We conducted simulations on the NS-2 simulator and the results show that our polling scheme can reduce the active time of sensors by a significant amount while sustaining 100 percent throughput. Key Words—Wireless sensor networks, Clusters, Polling, Multi hop Polling, Scheduling.