Digital television is a new, interesting, and rich platform for developing next generation multimedia services. Navigator is the most important Multimedia service of digital television. It acts as the main index of all the services available in set-top box. In this paper, we described the definition of a Navigator, its functionality, and its information source such as transport stream (TS) and Service Information (SI). The processes of developing a Navigator in Java are presented. A software model including navigation model and state model of a remote control is introduced. The conclusions part contains development issues and further research topics.