Energy efficiency enhancing techniques is wireless sensor networks
Zoltán Vincze · 2008
Wireless sensor networking (WSN) represents one of the most promising novel technologies. Thanks to the rapid development of the electronic devices, today it is possible to build tiny and cheap sensor motes with radio, sensing and processing capability. A network built from these devices is able to monitor different physical phenomena, process the data, and collect it at a central device, called sink. These networks can be used in almost every part of our everyday life, the number of applications is almost boundless. Initially the driving force behind the development of WSNs were the possible military applications, e.g., intelligent minefield, enemy monitoring, countersniper systems. As time passed, people recognized the applicability and the advantages of the WSN technology in several other areas, e.g., intrusion detection, seismic monitoring, wildlife habitat monitoring, oil and gas pipeline surveillance, or elderly care. However, to reach the commercial breakthrough, some important issues still have to be handled. One of these is the energy efficiency in WSNs. Due to the small size and low cost of the sensors, they can have only limited energy supplies. The research community usually assumes that in a typical WSN a huge number of sensors will be deployed, in a wide area that in addition might be also inaccessible. Under these circumstances it is almost impossible and surely not economical to recharge or replace sensor batteries. Thus, for an economical and reliable operation, WSNs have to use energy efficient techniques that prolong network lifetime as much as possible. Sensors use most of their energy for communication. The energy demand of a packet transmission is proportional to the communication distance; thus, reducing those distances can result in enormous energy savings. One solution for that is to use multiple sink nodes instead of just one. The resulting energy reduction depends mainly on the locations where the sinks are deployed. The existing deployment solutions are all based on the availability of global network information, which is an unrealistic assumption in case of large networks monitoring large areas. In this dissertation I propose a novel multiple sink deployment algorithm that uses only locally available information. I show that the proposed solution deploys the sinks very efficiently even in the case of heterogeneous network environments, resulting in longer network lifetime. Using a mobile sink can also significantly enhance energy efficiency of network operation. By moving the sink inside the network, the communication distances are reduced and the high