I. Introduction
Mobile devices have always been essential elements in our daily life, providing us with exciting functions such as interactive networking, online commerce, and entertainment. According to statistics from relevant agencies, there are nearly 7 billion IoT devices, and 3 billion smartphones in the world [1], which means that a large amount of data is generated at the edge of Internet. We all know that the machine learning technology is often used to analyze large amounts of data and obtain valuable information [2] to help human to reach the goal of classification, detection and prediction of the future.