Μελέτη προβλημάτων τοποθέτησης σε ασύρματα δίκτυα αισθητήρων
Date Issued
February 14, 2019
Type
Πτυχιακή Εργασία
Abstract
In this paper we will study problems of optimally placing a service in wireless sensor networks and also the energy behavior of these sensor networks. We begin with a quick overview of some basic graph theory and then move on by presenting the 1-median problem and its involvement in terms of the placing of a service over the network. We show with software simulation results the usefulness of the solution of the 1-median problem in a network regarding the total cost of communication with the service node. Then we analyze why the solution of the 1-median problem requiring general knowledge of network topology is not a viable strategy in wireless sensor networks that can have thousands of nodes and constant changes in topology (node additions, removals, and moving of nodes) and we implement a service relocation mechanism to dynamically move locations, with only local information as the mechanism criterion. Once we implement the so-called migration, we analyze its behavior in various network topologies through simulations. Finally, we take a look at how energy is consumed in the network and at the energy hole problem, and we show that the optimal position for energy starved networks is at the position of the solution of the 1-median problem. We finish off with service migration experiments with various parameters as we study the energy behavior of the entire network, and give thoughts on future directions for the subject.
Subjects