Information assurance in sensor networks

Sensor networks are deployed to monitor the surroundings and keep the end-user informed about the events witnessed. Different types of events have different levels of importance for the user. Information Assurance is an ability to disseminate different information at different assurance levels to the end-user. The assurance level is determined by the criticality of the sensed phenomenon. Thus, information assurance capability allows a sensor network to deliver critical information with high assurance albeit potentially at a higher cost, while saving energy by delivering less important information at a lower assurance level. In this paper, we look at the problem of efficient information assurance in sensor networks when the assurance level of information is defined as the probability of information delivery (desired reliability) to the sink. We propose a new scheme for information delivery at a desired reliability using hop-by-hop broadcast. We show how the wireless broadcast can be utilized to increase the packet delivery rate at each hop and attain a desired reliability at minimal cost. Finally, we derive the optimal strategy for allocation of desired reliabilities at each hop in order to attain any given desired end-to-end reliability