Cities of the Future: Employing Wireless Sensor Networks for Efficient Decision Making in Complex Environments

Decision making in large scale urban environments is critical for many applications involving continuous distribution of resources and utilization of infrastructure, such as ambient lighting control and traffic management. Traditional decision making methods involve extensive human participation, are expensive, and inefficient and unreliable for hard-to-predict situations. Modern technology, including ubiquitous data collection though sensors, automated analysis and prognosis, and online optimization, offers new capabilities for developing flexible, autonomous, scalable, efficient, and predictable control methods. This paper presents a new decision making concept in which a hierarchy of semantically more abstract models are utilized to perform online scalable and predictable control. The lower semantic levels perform localized decisions based on sampled data from the environment, while the higher semantic levels provide more global, time invariant results based on aggregated data from the lower levels. There is a continuous feedback between the levels of the semantic hierarchy, in which the upper levels set performance guaranteeing constraints for the lower levels, while the lower levels indicate whether these constraints are feasible or not. Even though the semantic hierarchy is not tied to a particular set of description models, the paper illustrates a hierarchy used for traffic management applications and composed of Finite State Machines, Conditional Task Graphs, Markov Decision Processes, and functional graphs. The paper also summarizes some of the main research problems that must be addressed as part of the proposed concept.