Energy Efficient Algorithms For Wireless Sensor Networks

This Master Thesis presents the developments in the routing algorithms for Wireless Sensor Networks. The energy efficient algorithms have been a subject to research for a few last decades due to its importance in the practical applications in real life. In this dissertation, a few most commonly used algorithms are analysed for different parameters of the sensor networks, namely:direct transmission, minimum transmission energy (MTE), LEACH, LEACH-c, and LEACH+MTE algorithms.A new program to study the parameter dependencies has been written in FORTRAN language. The results are presented for all sets of parameters, and the optimal conditions for the longest lifetimes for each algorithm are included. The developed program can easily be used for further analysis when only changing the input parameters.A new algorithm, named Directed LEACH (D-LEACH), is invented and developed as a main result of the thesis. This algorithm shows the longest lifetime for a wide class of network parameters, almost always prevailing over all the other analysed algorithms. In the optimal case of the perfect data aggregation, D-LEACH outlives all the other schemes by a factor of two (measured as an average lifetime). The algorithm is based on selection of the optimal route from each node to the Base Station via possible cluster heads. Optimizing the energy consumption, instead of choosing the shortest distance, ensures the longest lifetime. A scheme of sequential cluster head selection is computationally realizable and, thus, can be applied in the real life scenario.