The Impact of Different Propagation Environments on the Performance of Wireless Sensor Networks

Abstract

This dissertation presents a methodology for evaluating the performance of wireless sensor network (WSN) protocols in different propagation environments. To create this methodology, practical RF propagation models that include many of the substantial features of different propagation environments are utilized, and radio energy models for different propagation environments are developed. Accurate environment-specific radio frequency (RF) propagation models should be utilized in order to improve the overall process of decision-making during pre-deployment of WSNs, to facilitate the deployment of the WSN, and to enhance the battery efficiency of sensing nodes so that the network lifetime can be prolonged. The investigating of the impact of different propagation environments on the performance of WSNs was done based on simulating the LEACH protocol using the propagation models of sparse tree, concrete surface, sand terrain, long natural grass, short natural grass, artificial turf ground, and dense tree environments. Also, the LEACH protocol was implemented in MATLAB using the free space and two-ray propagation models with identical setups and conditions. In addition, environment-specific radio energy models to predict energy consumption of WSNs deployed in dissimilar outdoor propagation environments were developed. These models were derived based on the usage of precise environment-specific RF propagation models. The comparison metrics that were involved in this study are the lifetime of the network and the network throughput. The network lifetime definition that was used in this study is the death of the first sensor node, while the throughput is defined as the total number of packets successfully sent to the base station node. Moreover, the presented simulations are compared with each other so that the differences in the performance of WSNs in various propagation terrains can be identified. The results obtained through the comparison of these dissimilar outdoor propagation environments reveal significant differences in the lifetime and throughput. The differences are due to the dissimilarities existing in the wireless propagation channel of each environment. Furthermore, results generated by the developed radio energy models using these practical RF propagation models are compared with the results generated by radio energy models using free space and two-ray propagation models to demonstrate the imprecision of these theoretical propagation models in evaluating the performance of WSN in different environments.