Just read this interesting paper from MIT: Integrated Urban Sensing: A Geo-sensor Network for Public Health Monitoring and Beyond"
The paper looks at the opportunities becoming available from pervasive deployment of sensors in an urban environment. Here's the first part of the abstract:
Pervasive environmental monitoring implies a wide range of technical, but also socio-political challenges, and this applies especially to the sensitive context of the city. In this paper, we elucidate issues for bringing out pervasive urban sensor networks and associated concerns relating to fine-grained information provision. We present the Common Scents project, which is based on the Live Geography approach, and show how it can overcome these challenges....
and here's a paragraph describing the application of Complex Event Processing (CEP) technology:
Event recognition and processing happens in two different stages of the workflow. 1.) at sensor level, Complex Event Processing (CEP) is used to detect errors in measurement values by applying different statistical operations such as standard deviations, spatial and temporal averaging, or outlier detection. Thus, it can be considered a mechanism for quality control and error prevention. To be able to detect condition changes in measurement values, we enhanced CEP and Event Stream Processing (ESP) techniques by the location parameter. Thus, these methods can also serve for the federal organisation of pre-defined geographical domain violations like geo-fences, and for tracing and analysing spatial patterns. 2.) after the data harmonisation process, CEP serves for spatio-temporal pattern recognition, anomaly detection, and alert generation in case of threshold transgression
This is a clear use case for event stream processing in an "Internet of Things" scenario - but a big departure from the commercial applications that draw most of the attention.
Source: Resch, Bernd et al. "Integrated Urban Sensing: A Geo-sensor Network for Public Health Monitoring and Beyond." forthcoming in International Journal of Geographical Information Science