Impact of soil medium on the path connectivity of sensors in wireless underground sensor networks

This paper studies the impact of soil medium properties and network parameters on the topological connectivity of wireless sensor nodes communicating with each other via electromagnetic wave under the ground. The sensor nodes are deeply buried under the ground and randomly deployed in a square sensing area. Through two simulation scenarios, we investigate the path connectivity between two arbitrary sensors under various settings of soil moisture, sensor's density and operating frequency, and sensing area. It is shown that the water content in soil remarkably changes the influence of other factors on path connectivity. The results obtained in this paper provide useful guidelines on the design of reliable wireless underground sensor networks.