A measurement study of mobile video streaming by different types of devices There is an increasing demand for mobile video streaming. In order to improve the QoE of mobile videostreaming, it is important to understand the user interest, user behavior, and current QoE achieved in mobile video streaming systems. Past studies have compared mobile video streaming with that for non-mobile end systems (PCs). In this paper, we report the differences in user interest, user behavior and QoE for different mobile device types (phone versus tablets, and Android versus iOS). Our study is based on a large data set collected from a real world mobile video streaming service operated by our collaborator. Besides reporting the differences for these device types, we also report the extent thestreamed video is wasted (not viewed). It shows that there is a lot of room for improving the service QoE and efficiency.