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Overview of Microsoft WebTV for Windows

Microsoft WebTV for Windows 98, included in Windows 98, integrates the interactivity of the Web with the medium of television, providing interative television on a computer. With Windows 98 and a TV tuner adapter card supported by Windows 98 installed on your computer, you can:

Many kinds of applications can be run on Microsoft WebTV for Windows 98, from traditional Windows-based applications to standard broadcast TV programs. In between is a new application space: interactive television, is the melding of interactive content with an audio/video source.

For example, an interactive baseball game or cricket match might provide a score card, player stats, and a continuous ticker of scores from around the league, in addition to the television signal.

Currently, WebTV for Windows 98 supports both cable and over-the-air broadcast transmissions for National Television System Committee (NTSC) programming. Satellite and other broadcast transmission standards will be supported in the future.

In designing interactive content, internal Microsoft producers have been using a set of standards based on open, standard Internet technologies.

Interactive Television

The concept of interactive television is at the heart of WebTV. Interactive television combines television with interactive content and enhancements to provide better, richer entertainment and information, blending traditional TV-watching with the interactivity of a personal computer. Programming can include such items as: additional background text, richer pictures and graphics, one-click access to Web sites, electronic mail and chats, and online commerce with the use of a phone line back channel.

The process for creating interactive television is fairly simple. First, enhancement producers collect interactive elements on the set of a TV show. Then a Web developer assembles the elements using industry-standard languages and tools. Finally, the elements are transmitted within the live broadcast to the viewer’s Windows 98 supported TV tuner. The signal is sent over narrow bandwidths in the vertical blanking interval (VBI) of a television signal.

Interactive Programming

There are three basic levels of interactive programming:

Each of these options offers varying degrees of interactivity. Each of these types of interactivity is viewable by both Windows 98 and the WebTV Plus set top box. In other words, a broadcaster can send one signal and have it received, decoded, and rendered by both clients.

TV Crossover Links

TV Crossover Links are very easy, yet a very powerful way to marry television programs to their associated Web sites. TV Crossover Links enable producers to integrate a Uniform Resource Locator (URL), or what is considered the common Web page address, directly into an actual TV program through closed captioning. A "trigger" in the form of a graphic "i" appears as a small "watermark" overlaying the program. Viewers can click on the "i" with their mouse or remote control to visit the associated Web site. By sending a trigger over the closed-caption signal, shows can add static or dynamic Web links to their programming.

Since the closed captioning space is available throughout the duration of the program, multiple TV Crossover Links can be sent during a broadcast. Most programs currently include closed captioning information, so the tools needed to add TV Crossover Links to a program already exist.

Low Bandwidth (Analog) Interactivity

The second level of interactive programming is the ability to integrate Web-based information and video programming using current analog transports. By using the bandwidth available in the vertical blanking interval (VBI) of a television broadcast, show producers can synchronize useful and timely information with an existing television program. An integrated page is created combining the television’s video signal with content that enhances the viewer’s TV experience. This second level of programming allows for a more user-driven experience than TV Crossover Links by delivering interactivity to each viewer.

Using well defined and understood Internet Protocols (IPs), broadcasters can send additional information alongside their signal. Although this is available today, there is limited bandwidth in the VBI for sending data (essentially what amounts to the bandwidth of an Integrated Services Digital Network [ISDN] line), so only limited interactivity and information access is currently attainable. However, when combined with a back channel, the option to add e-mail and chat rooms expands the possibilities of this current technology.

High Bandwidth (Digital) Interactivity

The third level of interactive programming consists of delivering integrated video and multimedia programs through fully digital transports such as digital terrestrial high-definition television or digital satellite. When this level of programming is realized show producers will have greater bandwidth for delivering program enhancements, finer control over the synchronization of information and video, and more flexibility in the layout and integration of pages.

Technologies Involved

The following is a list of the technologies that Microsoft WebTV for Windows 98 uses: