Performance Analysis of a Wireless Sensor Network for Seism Detection in an Overlay Cognitive Radio System

This paper studies the performance of a wireless sensor network (WSN) with cognitive radio (CR) capabilities to gather information about structural health monitoring (SHM) of buildings in case of seismic activity. The system performance is evaluated in terms of energy consumption and average packet delay using a discrete event simulator. In order to efficiently use the resources of the network and considering that the WSN will be installed in office or home buildings, we propose the use of the empty (white) spaces in a conventional cellular system. Thus, the WSN will act as secondary network, which do not affect the quality of service of the primary network, since it will work in an overlay structure. The main performance parameter of the primary network is the blocking probability since a Blocked Call Cleared (BCC) system is considered. By using the data collected in the WSN and transmitted through the unused channels of the cellular system, it is possible evaluate the damage caused by the seismic activity in a certain building. The major benefit of using a WSN with CR capabilities compared to the traditional approach, i.e., only one sensor per building floor or even per building is that with the WSN it is possible to collect much more information related to both the seism and the effects on the monitored building without the additional traffic in the already crowded unlicensed spectrum.