improving security applications using indoor location systems on wireless sensor networks
One of the fields in which companies are investing more money is security, either personal security to avoid industrial accidents or security against intrusions. There is also the huge effort that the scientific community is doing developing all required protocols and standards to make Wireless Sensor Networks (WSN) extensive commercial. Moreover, one feature that will highly increase the use of these networks is the automatic localization of any sensor inside the network. In this paper we present several use cases where localization over Wireless Sensor Networks is used to reinforce security. In order to test the current feasibility of exiting commercial products to build such systems, we have developed an application that helps us to obtain real measures of accuracy. The essential part of localization is range measurement that can be performed by time of arrival, time difference of arrival, received signal strength indication or angle of arrival. Nevertheless, not all commercial products permit to measure all these parameters. The easiest solution is the use of received signal strength, but it is also the less accurate. There exist some platforms that additionally allow to measure time difference of arrival. In the presented solution we have adopted one of such sensor devices, although time measures are done using ultrasounds. As the range of them is quite low, our solution implements an algorithm that combines both measures, time and signal strength in order to obtain the most accurate possible localization.
security applications indoor location systems wireless sensor networks ils ieee 802.15.4