doi:10.3850/978-981-08-7301-1_1637

ABSTRACT

Heterogeneous Wireless Sensor Network are hierarchically clustered. In these networks some of the nodes become cluster heads, aggregate the data of their cluster members and transmit it to the sink. We assume that a percentage of the population of sensor nodes is equipped with additional energy resources—this is a source of heterogeneity which may result from the initial setting or as the operation of the network evolves. We also assume that the sensors are randomly (uniformly) distributed and are not mobile, the coordinates of the sink and the dimensions of the sensor field are known. We show that the behavior of such sensor networks becomes very unstable once the first node dies, especially in the presence of node heterogeneity. Classical clustering protocols assume that all the nodes are equipped with the same amount of energy and as a result, they can not take full advantage of the presence of node heterogeneity. We propose a scheme, to prolong the time interval before the death of the first node (we refer to as stability period), which is crucial for many applications where the feedback from the sensor network must be reliable. Our proposed scheme is based on weighted election probabilities of each node to become cluster head according to the remaining energy in each node. We show by simulation that proposed scheme always prolongs the stability period compared to (and that the average throughput is greater than) the one obtained using current clustering protocols. We found that proposed scheme yields longer stability region for higher values of extra energy brought by more powerful nodes.

Keywords: Wireless sensor network, Heterogeneous sensors nodes, Optimum deployment, Network lifetime.

© 2011 ICCA 2010 Organizers