This year’s Student Innovation Challenge addresses the topic of analyzing sensor data in the Sensor Web and generating higher level information products. My research topic draws inspiration from smart city applications. To be more specific, IoT sensor web technologies and 3D city models play significant roles in building the smart city. I argued that most of the existing solutions to integrating 3D city models and sensor observations are usually customized and lack interoperability. Therefore, in order to improve the interoperability of smart city models, I conclude that the integration of the IoT sensor service and the 3D city model have to be based on open standards.