Cmmb Data Broadcasting Platform-based Design And Realization

Since China Mobile and China Unicom launched mobile TV business in 2004, mobile TV has been called"The Third TV",following TV and Internet. At present, there are two main methods of implementing the mobile TV business. The first is the use of cellular mobile networks. For example, American Sprint, China Mobile and China Unicom are using this approach. The second is the use of satellite/terrestrial broadcasting system, which Korean operators adopt. CMMB (China Mobile Multimedia Broadcasting) is a new generation of multimedia broadcasting technology and supports a variety of mobile terminals. It uses the second approach mentioned above. It is independently developed by the State Administration of Radio, Film, and Television (SARFT), and is in line with China's national conditions. The Part V of the CMMB standard is Data Broadcasting, which met the demand for information by vast number of users. It enables users to obtain more graphics, text, games, data, and online update. Other functions such as interactive features can also be achieved with network support. Per SARFT's request, we set up the CMMB data broadcasting platform, which provides significant practical meanings and economic benefit.This dissertation first studies and analyses CMMB's background, as well as some technologies at home and abroad which are similar to CMMB. Then it outlines the CMMB standard system, emphasizing on the principle, characteristics and key technology of data broadcasting. According to data broadcasting's business features and functional requirements, a solution named CMMB data broadcasting platform has been designed and implemented based on the data broadcasting front-end network. This platform can manage the entire CMMB data broadcasting process, including controlling program playing, encapsulating the business data and monitoring real-time data. This platform includes three sub-systems: document generator, XPE package and bit stream analysis system.In order to improve the performance of data broadcasting when implementing the document generator, this dissertation provides in-depth analysis of the data broadcasting protocol for data files and FAT partition file transfer theory, and consequently designs and realizes a set of partition and encapsulation flows. At the same time, different file carousel strategies have been designed according to the features of data file and FAT file. When implementing bit stream analysis system, in view of the front-end network and operation situation, a set of reverting and emulating flows have been designed based on terminal receiving principle, including general flow, XPE/XPE-FEC data package handling flow, FAT file handling flow and data file handling flow. At last, this dissertation provides in-depth analysis of the data validation mechanism of data broadcasting, emphasizing on RS(255,207) error collection validation algorithm and LDGC erasure validation algorithm, then realizes some key parts of them to make sure data integrality and accuracy during transmission.