New interactive services for digital TV
Current interactive TV services are limited. They mainly consist of accessing the World Wide Web. These services basically display a Web page beside a TV program that is related to the contents of TV program. We define new interactive services for digital TV, which can be used in many attractive applications such as parental management, multilingual audio and video in video. These services have also the advantages that they do not require an Internet return path and that they preserve the compatibility of the transmitted stream with conventional TV systems and receivers. In this paper we evaluate the feasibility of the proposed interactive services for digital TV and specify the challenges and problems in implementing these services. We present methods for overcoming these problems. We also specify the minimum decoder buffer required and the average random access delay for multilingual support in a typical standard definition TV program.