sim 文件系统In addition, its quality of service reduces because of reliance on traditional circuit-switched network elements. At that former time, people hoped to build a based system, which could access a centralized server network, would always have access to the latest traffic information and could provide web links. What this trend is a momentous request for mobile services based on high-speed packet data transfer. Hence, a new standard, GPRS, came into being in order to fill people’s bill.