Digital television

DTC advertising is prohibited within the EU, but is seen as inevitable to some extent anyway due to international access to the Internet and digital television ( t Hoen, 2003). This prohibition is to the extent that medical journals bearing drag advertisements on their covers cannot be mailed in see-through bags unless such advertisements are obscured with additional pieces of paper inside the wrapper. 

Digital Television (DTV) Television on which the picture information is transmitted in digital form rather than via an analogue signal. 

High-Definition Television (HDTV) Digital television system that has twice as many scan lines per fi-arne, a wider format, and sharper image quality than conventional television. 

Overview of the ATSC Digital Television System Video... 

VHF and UHF transmission frequencies between 200 and 900 MHz were used for the demonstrations with satisfactory results. Because most VHF and UHF frequency bands suitable for DAB are already in use (or in use by/reserved for digital television and other services), an additional Canadian study in 1991 evaluated frequencies near 1500 MHz (L-band) for use as a potential worldwide DAB allocation. This study concluded that L-band frequencies would support a DAB system such as Eureka-147/DAB, while continuing to meet the overall system design goals. 

This section is based on ATSC, Guide to the Digital Television Standard, Doc. A/54A, Advanced Television Systems Committee, Washington, D.C., 2003. 

A basic block diagram representation of the DTV system is shown in Figure 16.49. According to this model, the digital television system consists of four major elements, three within the broadcast plant plus the receiver. 

While not required by the DTV standard, there are certain digital television production standards, shown in Table 16.11, that define video formats which relate to compression formats specified by the standard. 

The following service types are defined in the digital audio compression (AC-3) standard [2] and in the ATSC digital television standard [ 1 ] ... 

The transport subsystem employs the fixed-length transport stream packetization approach defined in ISO/IEC13818-1 [12], which is usually referred to as the MPEG-2 systems standard. This approach is well-suited to the needs of terrestrial broadcast and cable television transmission of digital television. The use of relatively short, fixed-length packets matches weU with the needs and techniques for error protection in both terrestrial broadcast and cable television distribution environments. 

PSIP is a collection of tables, each of which describes elements of typical digital television services [13]. Figure 16.53 shows the primary components and the notation used to describe them. The packets of the base tables are aU labeled with a base packet identifier (PID). The base tables are... 

Standard definition television (SDTV) This term is used to signify a digital television system in which the quality is approximately equivalent to that of NTSC. This equivalent quality may be achieved from pictures sourced at the 4 2 2 level of ITU-R Recommendation 601 and subjected to processing as part of the bit rate compression. The results should be such that when judged across a representative sample of program material, subjective equivalence with NTSC is achieved. Also called standard digital television. 

Bentz, C. 1988. Inside the Visual PA, Part 2. Broadcast Engineering, Intertec Publishing, Overland Park, KS. Bentz, C. 1988. Inside the Visual PA, Part 3. Broadcast Engineering, Intertec Publishing, Overland Park, KS. Robin, M. and Poulin, M. 2001. Digital Television Fundamentals, 2nd ed. McGraw-Hill, New York. 

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