Increased adoption of smartphones leads to the explosive growth of mobile network traffic. Understanding the traffic characteristics of mobile network is important for Internet service providers(ISPs) to optimize network resources. In this paper, we conduct a detailed measurement study on the hyper text transfer protocol(HTTP) traffic characteristics of cellular network among different operating systems(OSs) as well as different device-types. Firstly, we propose a probability-based method to identify the installed OS of each smartphone. Then we analyze the traffic characteristics of these smartphones in terms of OS and device-type based on a dataset across 31 days(a billing cycle). Finally, we identify the installed apps of each smartphone and compare the usage of apps on the dimensions of OS and device-type. Our measurement study provides insights for network operators to strategize pricing and resource allocation for their cellular data networks. Increased adoption of smartphones leads to the explosive growth of mobile network traffic. Understanding the traffic characteristics of mobile network is important for Internet service providers (ISPs) to optimize network resources. In this paper, we conduct a detailed measurement study on the hyper text transfer protocol (HTTP) traffic characteristics of cellular network among different operating systems (OSs) as well as different device-types. Firstly, we propose a probability-based method to identify the installed OS of each smartphone. smartphones in terms of OS and device-type based on a dataset across 31 days (a billing cycle). Finally, we identify the installed apps of each smartphone and compare the usage of apps on the dimensions of OS and device-type. study provides insights for network operators to strategize pricing and resource allocation for their cellular data networks.