ABSTRACT
The smart city is a complex concept which integrates diverse technologies to resolve the new problems in cities. In the modern city, licensed and unlicensed radio signals are widely used indoor and outdoor for multiple purposes: from wireless communications, broadcasting to localization, navigation and remote sensing. The most common application of radio signals in urban settings is communications, including the mobile communications over licensed carrier bands and wireless access over ISM bands. Besides the localization, existing outdoor radio signals can also be used for capturing the instant motion status of targets of interest by using passive detection. Similar to the outdoor applications, accurate position and instant motion are also important for indoor applications like health care, indoor navigation and robotics. With the enrichment of the physical space and infrastructures of cities, along with the increased capability of smart devices and agents across different scales, the idea of a smart city has moved towards reality.
