Recently, secondary use of white-spaces has been expected as one of the technologies to mitigate spectrum resource shortage problem. In particular, secondary utilization of white-spaces in the TV band (TVWS) has attracted attention and some standardizing activities such as IEEE802.11af and IEEE802.22 have been promoted. For the mobile communication systems, it is possible to secure more channels for traffic balancing by utilizing the TVWS, while there are still some difficulties in miniaturization and low power consumption for TVWS utilization. In this study, the authors prototyped a smart phone type TV band device, which supports a TVWS LTE system, by applying frequency conversion technology. This prototyped smart phone is fully operated by an internal battery and can connect to the TVWS eNB previously developed by the authors. Commercial LTE Band 1 is also supported and the phone can select and smoothly switch between two bands. This is the world’s first prototyped smart phone supporting the TVWS that demonstrates not only the feasibility of miniaturization and low power consumption, but also the possibility of spectrum expansion in mobile communication system towards next generation.