This article discusses the aspects of DTT broadcasting which are of concern to all administrations that intend to adopt it as a replacement for analog terrestrial television. The first section summarizes the broad goals that can be achieved with DTT broadcasting. The second section is dedicated to common policy topics related to the adoption of DTT technology. Finally, the third section discusses the importance of spectrum planning in the analog to digital transition task.

1. Broad Goals of DTT Broadcasting

This section is intended to summarize the extensive range of capabilities of DTT broadcasting technology and the broad goals that can be achieved through its application and is neither related to the specificities of the proposed standards nor strictly related to national experiences on the implementation of this technology.

1.1 Improved Technical Quality

Digital transmission itself offers a significant improvement in the technical quality of images and associated sound, e.g., by eliminating snow and ghosts. In addition, HDTV offers six times as much picture information, offering much sharper, clearer images, which combined with a widescreen display format and six channels of CD-quality surround sound represents a quantum improvement in the technical quality of broadcast television services. Rapid decreases in the prices of HDTV displays and receivers have contributed to tremendous consumer interest in HDTV products and services.

1.2 Increased Quantity and Variety of Services

DTT technology also enables the offering of several simultaneous services of SDTV quality, increasing the quantity and variety of services that can be provided to broadcast television viewers. For example, noncommercial broadcasters can use this capability to provide multiple educational programs to schools and homes. With system configurations designed to maximize the bit rate available in a DTT broadcast channel, a single broadcaster can provide various combinations of such services, for example, one HDTV program, one SDTV program (e.g., a 24-hour news program), and several web pages (e.g., weather maps, sports scores, etc.), all in a single 6 MHz television channel.

1.3 New Information Services and Social Inclusion

DTT broadcasting enables a limitless variety of new information services, including interactive services. Information services may be integrated with video programs or independent of such programs. A great deal of interactivity in such applications can be provided simply by downloading substantial information from which viewers can choose. Interactivity can be increased further through the use of a return channel through which viewers can request specific content from the broadcaster. Multiple technologies exist to implement the return channel, including, but not limited to, fixed and mobile networks, broadband connections or even a terrestrial return channel if additional spectrum is available.

The use of DTT to provide information services, including interactive services, represents an important opportunity to promote social inclusion, i.e., to provide education, health care, and other important social services to viewers of all socio-economic segments, including citizens who may never own a personal computer.

1.4 Service to Hand-Held Receivers and Mobile Services

In addition to reception by fixed receivers with either external or indoor antennas, DTT broadcasting enables the delivery of programs and applications to hand-held devices, characterized by relatively small displays and the necessity of reduced power consumption. Such devices, typically mobile phones and PDAs, can be equipped with DTT demodulators in order to enable reception of broadcast content anytime and anywhere. As such, these hand-held devices can be considered as a point of convergence between the telecommunication and broadcasting networks. In some cases, services provided to hand-held devices may also be provided independently of the digital terrestrial television service, using additional spectrum.

DTT broadcasting also provides the capability for reception by moving receivers, i.e., in fast-moving vehicles such as trains, buses, boats or automobiles. Mobility does not necessarily involve low battery consumption and typically requires medium to large displays and therefore should not be confused with services provided to handheld devices.

Both mobile reception and service to handheld devices require reductions in the bit rate that can be delivered in a terrestrial channel. Thus, depending on the amount of mobile or hand-held services provided and the robustness of such transmissions, the provision of such services could detract from the quality and/or quantity of services that could be provided to fixed and portable DTT receivers.

1.5 Spectrum Efficiency and Recovery

DTT broadcasting makes much more efficient use of the electromagnetic spectrum than analog broadcasting, and the conversion to digital broadcasting offers the opportunity to recapture and reuse valuable spectrum for other innovative wireless services. For some countries, this opportunity will be a driving force in the effort to hasten the transition to digital broadcasting.

1.6 Industrial Development and Economic Growth

The transition to DTT broadcasting represents significant opportunities to promote industrial development, job creation and economic growth, depending on the individual characteristics of each country and the policy decisions it adopts.

1.7 Other Goals

A timely and well-planned introduction of DTT broadcasting can be a major factor in a country’s technological, economic, and social development. To this end, the following goals should also be considered:

• Adaptability to socio-economic conditions

• Allowance for gradual implementation, minimizing social risks and costs

• Taking advantage of economies of scale

• Protection of consumers against premature obsolescence of their analog or DTT products

• Provision of new applications that facilitate access to culture, information, and entertainment

• Promotion of content production and new business opportunities

• Development of solutions that support cultural and educational development

• Promotion of social inclusion, cultural diversity of the country, and the official language through access to digital technology, aiming at democratizing the information

In considering all of these goals, it is of utmost importance that each country establish DTT policies that promote appropriate investments and support business models that will be successful, recognizing the unique economic, social and business conditions that prevail.

Ara Minassian
Vice Chair
Working Group on Broadcasting