NETWORK AND ROUTE OPTIMIZATION IN WIRELESS SENSOR NETWORKS

Abstract

Wireless sensor network (WSN) is a new class of wireless networks that are made up of tiny sensor nodes ranging from tens to thousands in number which are meant to monitor physical or environmental conditions by establishing connection with each other to exchange information and data. These sensor nodes obtain information on the environment such as temperature, pressure, humidity or pollutant, and send this information to a base station. The latter sends the information to a wired network or activates an alarm or an action, depending on the type and magnitude of data mon itored. This characteristic of wireless sensors makes them very popular and trendy with a huge number of civilian and military applications in the present world. Another characteristic of wireless sensor nodes is that they are power constraint as the only source for their energy is non-rechargeable battery. Once the power of nodes gets drained they would not able to perform any task in the network and so the network functionality gets broken. Therefore issues related to power conservation of nodes, redundant power consumption, network lifetime etc have been tried to resolve since past many years under different factors and still in progress. The work in the thesis has been greatly motivated by the existing models and opti mization techniques, introduced in the field of WSNs to deal with the network issues. We have addressed more issues/challenges and introduced new graph theoretic mod els along with new algorithmic approaches of lesser time complexity to provide the optimal solution to many problems. This thesis provides good amount of analysis on nodes’ energy consumption and network disconnectivity conducted via simulation work on different scenario possible in WSNs. We have compiled the work of the thesis in 6 chapters where chapter 1 is introduc tory in nature. Chapter 2-6 provide the study on different problems and requirements of WSNs and put-forth satisfactory solutions to the problems along with analysis. Fur thermore chapters 1, 2, 5 and 6 are based on the research work published in the vii form of research articles in reputed refereed journals and rest of the chapters are communicated research papers. After chapter 6, we have presented the summary of the research work carried out in the thesis. In addition, the future scope of the thesis has been discussed briefly. Finally the thesis is ended with the bibliography and list of publications.