DigitalTV: Roughly 75 PBS stations have made the conversion to DTV so far. When do you anticipate all PBS stations will be digital?
Tollefson: Our goal has always been to have all 349 public television digital transmitters on the air by the deadline of May 1, 2003. We began the journey in November of 1998 with just seven digital pioneering stations. Since then, member stations have been steadily coming on the air and many more are in various stages of completion. There are now 75 PBS member digital stations on-air, providing over 55 percent of the U.S. TV households with digital television.
Each member station determines when and how it starts digital broadcasting. In some markets, the challenges are technical, such as antenna placement, while for most stations funding remains a major factor. To address the funding issue, PBS is managing the distribution of funds from the Corporation for Public Broadcasting (CPB) to help stations get on the air with basic DTV service. With this help, PBS expects virtually all public digital stations to be on the air by May 1, 2003.
DigitalTV: Why has PBS made the decision to transition its stations to DTV sooner than its government mandate?
Tollefson: Each station makes the decision on when a member station will begin digital broadcasting. PBS is encouraging all stations to begin as soon as possible and makes available both high definition and multicast signals as content for the digital transmitters.
PBS has maintained the position for many years that digital television will benefit the American public by providing more streams of content to fulfill the public broadcasting mission and providing many programs in high definition to create a more compelling experience. The sooner public television provides these services, the better for the American people.
DigitalTV: While many broadcasters are complaining about the high cost of the digital conversion, public stations have always operated with limited funds. Despite this, they have consistently lead the way in the use of new technology. How has this been possible?
Tollefson: PBS is very proud of technical accomplishments that have provided greater services for the American public. In some cases the very fact that PBS has had limited financial resources has driven the development of technology to increase efficiency, reliability, and quality. Also, since the goal in public television is not to increase profit, but to increase services to the American people, PBS is always looking for new applications of technology. Often, this results in technology leadership.
DigitalTV: Due to its storied educational mission and distance-learning history, digital multicasting would seem to be a perfect fit for PBS. How will PBS stations continue this strategy in the digital realm?
Tollefson: Digital television provides new opportunities to serve the American public in three ways. First, multicasting provides the long-sought additional channels for cultural, informational, and educational uses of television. Until now, public television has been forced to choose between adult, secondary, elementary educational programs, cultural programs, informational programs, and other content of interest to the public. With DTV, several of these needs can be simultaneously addressed. Second, many of the programs broadcast on public television will be enhanced by presentation in high definition. Nature, science, history, and performance programs are far more compelling in high definition.
Third, digital television allows for distribution of significant amounts of additional data with television programs. This will provide services we now only dream about and many no one has thought of yet. PBS member stations have a wide range of plans for multicasting, including children's programming, education programming, and local government and information channels. Stations will respond to the needs of their local communities as they plan for full digital implementation.
DigitalTV: Several regional PBS stations have joined together in what are called Advanced Digital Distribution Entities (ADDEs), which look very similar to what other broadcasters call digital centralcasting. Explain when these systems will be in place and how the two strategies differ.
Tollefson: The Advanced Digital Distribution Entity that is the most developed is in the Northwest, where 11 stations are working together to develop a regional system for storage and distribution of national, regional, and local programming. Centralcasting is one potential service for the ADDE, but an ADDE can also provide a means to distribute local programming to other stations in the region. As with most projects, a technical infrastructure is required, and the Northwest ADDE has not yet identified a source of funding. Therefore, it is not known when the ADDE may be fully implemented.
DigitalTV: The PBS Engineering Advisory Committee is actively involved in determining the direction of PBS technology. Do individual stations have any input?
Tollefson: The PBS Engineering Advisory Committee is a valuable tool for PBS as it determines how best to serve the member stations. It is made up of representatives of all the regions of the country and groups affiliated with public broadcasting. The members of the Committee regularly poll the stations in their region on various technical subjects to be sure the stations all have a voice in determining technical policy at PBS. Through the years, many of the technical advances made by PBS are the result of a unique collaboration between PBS and the PBS Engineering Advisory Committee.
DigitalTV: PBS is working with new technologies that extend coverage beyond normal service areas of individual stations through the use of on-channel and synchronous repeaters as well as traditional translators. Would this technology work for commercial broadcasters as well?
Tollefson: PBS member stations in Pennsylvania are implementing a new use of the digital television transmission standard to better serve the public in Pennsylvania. Digital transmission technology provides opportunities for synchronous on-channel transmitters that are especially helpful in difficult terrain. Certainly the technology is applicable to commercial broadcasting as well.
DigitalTV: The PBS Technical Operating Center (TOC), in Alexandria, VA, is a model of efficiency and reliability according to those closely involved with it. What are some of its unique features?
Tollefson: The TOC has been completely digital for nearly 10 years. PBS made use of multiple channel automation systems and video servers in order to provide high quality and reliability for its multiple feeds at a reasonable cost. For many years, PBS has been using MPEG-2 multiple channel digital signals over satellite to member stations for efficient use of the transponder capacity.
Although PBS is proud of its accomplishments and present service to the member stations, we have begun a TOC redesign project that will significantly improve our quality, reliability, and efficiency. By the end of 2004, PBS will have new servers and archive systems; incorporating asset management and streamlined operational procedures.
DigitalTV: Do you think that the fact that many stations, including PBS members, are operating at low power is impeding the penetration of DTV into Americans homes? Isn't this not a good strategy to take if you want to introduce a new TV system to consumers that already have two digital TV options?
Tollefson: The ideal is to provide high power DTV service to every home in America. However, severe financial restraints have caused many PBS member stations to first assure they retain the digital channel with a low cost, medium power installation. For many member stations, the choice is medium power, or no power. PBS is helping these stations by providing information on medium-power solutions and making available CPB funds to first get on the air in a way that the station can later upgrade to higher powers.
DigitalTV: What's the biggest hurdle, in terms of the transition to digital, for PBS stations going forward?
Tollefson: The biggest hurdle to full implementation of digital television remains adequate funding. In a depressed economy, when many PBS member stations are hard-pressed to maintain current operations and services to their communities, finding additional money to pay for a digital broadcast system is a real challenge. And the initial installation is only the beginning. To realize the opportunities DTV offers, operating costs will also increase.
DigitalTV: In light of increasing competition, can PBS continue to operate as a free over-the-air service in the future?
Tollefson: Competition for PBS is not the issue. PBS has always had its best content ideas used by others in competition for viewers. PBS's success has always come from new ideas, from taking risks that commercial entities cannot afford to take, and from serving the American public in varied ways. PBS and public television in America will survive because there is a thirst for content that no one else provides. The American public appreciates PBS and the services the member stations provide, and it will continue to support public television.
Kevin Mortimer is a contributing writer for DigitalTV.
<font color="cc0000">A TRIBUTE TO PBS</a><br>PBS's Diverse Digital World
Approximately 75 of the roughly 349 PBS stations in the U.S. are transmitting a digital signal, covering around 55 percent of households in the country. But ãdigitalä is a complex term, meaning anything from standard definition transmission of television signals to nonlinear editing.