How should we use the bandwidth? This is perhaps the toughest question in DTV programming. That is because DTV programming includes traditional video program content as well as non-program data applications within the 6 MHz bandwidth.
One pioneering DTV application that maximizes bandwidth will be New Jersey Network (NJN) Public Television and Radio’s interactive weather channel — a service that does not require a back channel for the viewer to request additional information. The Advanced Television Enhancement Forum (ATVEF) Transport B specification makes this possible. NJN teamed up with AccuWeather, Zenith Electronics and Triveni Digital to implement this data virtual channel.
With AccuWeather’s highly localized weather-data service and NJN’s statewide DTV transmission infrastructure, the main challenge was formatting and embedding the weather information within the ATSC transport stream.
The solution uses an innovative architecture. Triveni Digital formats the AccuWeather data into a visual presentation form and then embeds it within the NJN DTV signal using Triveni’s SkyScraper interactive DTV broadcast system. Specially designed Zenith set-top boxes then receive the signal throughout New Jersey.
This architecture permits rich weather content to be sent to large numbers of receiving devices simultaneously, giving each viewer the freedom to interact instantaneously with the received content on an individual basis. And it doesn’t require a back channel of any type — such as a telephone line or an Internet connection to a central server.
This application uses the ATVEF Transport B specification to send interactive TV data over the DTV spectrum. As such, the STB’s memory stores all data, which is available for interactive retrieval by way of the viewer’s remote control. The viewer can bring up various screens of weather information related to cities in New Jersey as well as other selected cities on the menu.
The main benefit for viewers is speed and convenience. Compared to other means of accessing weather data, DTV-based interactive weather information is compelling in that it provides immediate access and frequent updates, as well as ease of use. Rather than having to download a Web site or wait for local weather information from a cable weather channel broadcast, DTV-based interactive weather information is always available to the viewer because all up-to-date information is stored within the STB. Taking advantage of the ATSC DTV standard that provides a flexible, broadband 19.4 Mbits pipeline, NJN plans to expand the portal offering to include local traffic, news and other innovative localized channels.
These benefits are important to NJN because it is a test site for national demonstration projects to broadcast data, text, graphics and audio and visual information, along with high-definition and multiple-program materials. NJN’s goal is to offer New Jersey viewers an expanded, interactive and enriched world of learning in their homes, schools and workplaces. In the case of interactive weather, the goal is to provide viewers with the exact weather information they desire —when they need it.
Triveni Digital’s SkyScraper Interactive and their custom solutions team serve as the enabling components between the information provider (AccuWeather) and the broadcaster (NJN). The system includes headend servers to manage the data flow from the information provider to broadcaster, and it lets broadcasters create new ways to reach viewers and generate potential revenue streams. It is a flexible solution that makes it easy to insert interactive material either during program development for program-specific interactions or as stand-alone interactive data blocks. Interactive content can be added to live programming on the fly for sporting events or breaking news coverage, making additional information available to viewers for interaction.
Each station’s DTV bandwidth-scheduling conditions are unique. Some stations may broadcast multiple programs simultaneously, each with its own data enhancements. Insertion of enhanced commercials may affect bandwidth for regular program enhancements. SkyScraper Interactive takes many factors affecting bandwidth use into account in real time, and optimizes the insertion timing of interactive data into the broadcast stream.
Broadcasters can integrate the system into almost any DTV station environment without the cost of re-training personnel. The system is interoperable with major data-enhancement authoring systems, traffic and automation systems, multiplexers or IP-to-MPEG-2 gateways. It also has built-in support for Triveni Digital’s GuideBuilder metadata-generation system, allowing broadcasters to rapidly enable and automate the inclusion of data enhancements in their PSIP and electronic program guide data.
Interactive local information accessible via television is an attractive way of using the vast DTV bandwidth while providing local viewers with something they can use easily and quickly as they go about their daily lives.
Jonathan Schembor is vice president of customer services for Triveni Digital.
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