Research And Implementation Of Interactive Services In IPTV

The digital TV technology improves the efficiency of bandwidth usage. Data can be transported in the digital TV system as well as the TV programs, which results in a series of new services in digital TV. One of such services is interactive services. From the narrow sense, interactive services should have a return channel for end users communicating with the interactive servers. From the broad sense, no matter there is a return channel, interactive services are those services which can be operated or controlled by end users. Since interactive services appeared, it becomes a new economic growth for digital TV. In the traditional digital TV system, interactive services are mainly local interactive services which also have got great development. Currently, with the development of triple networks' convergence, IPTV, a realization of such convergence, has been got great attention. With the development of IPTV in foreign countries, Triple-Play can be realized in IPTV. Otherwise, the transport network of IPTV, IP network, is a bidirectional network. These two reasons endow interactive services a real bidirectional feature and various kinds of applications. Therefore, interactive services in IPTV are not only feasible on the technical sense but also have a huge market.This paper first introduces the appearance,definition and development of interactive services, and summarizes features of interactive services in IPTV. Then, it brings the features and transport protocol of data broadcasting services. Though, most data broadcasting services are local interactive services without a return channel, it gives a wonderful watching experience for users and is also an obvious difference between digital TV and analog TV. EPG, as an important part of data broadcasting system, can be implemented in two ways which are compared in this paper. Then, the features and marketing requirement of interactive services in IPTV are summarized in this paper. To solve the problems in the implementation of interactive services, the encapsulation mechanism of interactive information and PCR restamping are investigated, and then a method for encapsulating interactive information is given, as well as the method for PCR restamping. In the end, the general framework model of interactive services system is given on the basis of DVB-IP gateway. As followed, the system of inserting interactive information in IPTV is implemented on the DVB-IP gateway. All methods and technical problems are investigated deeply and have been verified through experiment.