Rank-based Data Gathering in Wireless Sensor Networks

We propose a Rank-Based Data Gathering (RBDG) algorithm for wireless sensor networks with randomly distributed sensor nodes. For every round of dasta communication, the algorithm functions as follows: A set of sensor nodes or vertices are assigned a random rank between 0 and 1. A link is formed between any two nodes if they are within each other‘s transmission range. If a sensor node has the highest rank among it neighbors, then it is considered an associate node, else it is categorized as a leaf node. Next, we form a complete graph among the associate nodes with edge weights representing the physical Euclidean distance between the nodes. We run a minimum spanning tree algorithm on this complete graph and transform it to a rooted directed data gathering tree with the root being the sensor node with the highest residual energy. We also developed an energy-efficient version of the rank-based data gathering algorithm (EE-RBDG) wherein the rank of a node is the sum of the random number (between 0 to 1) assigned for the node and the fraction (also from 0 to 1) of the initial energy currently available at the node. Simulation results indicate that the E-RBDG algorithm performs better than the RBDG and other wellknown data gathering algorithms with respect to network lifetime, delay and energy*delay per round.