High Definition Television (HDTV)

Walter Boza (Editor: Rachel Chertkoff)

 

Technology applied to communication industries seems to work in two directions: 1) providing more efficient information and entertainment devices, which includes the creation of faster media and higher number of options, and 2) improving the quality of the services already in the market.

 

The television industry could be taken as a perfect example of the above. In the early days there were only a few broadcasters with limited air time, transmitting a poor quality black-and-white picture, while today we have not only increased the number of national broadcasters, but have also added cable and satellite TV, which transmit a significantly better picture, enhancing it with color. High Definition Television (HDTV) appears to follow the same trend, since the technology applied in it is capable of both increasing image quality and the number of channels available for transmission.

 

HIGH DEFINITION TELEVISION (HDTV)

The basic concept of HDTV implies a better image quality by the use of a wider screen and digital technology; while current TV formats have an aspect ratio (viewing screen size) of 4:3, HDTV is intended to have an aspect ratio of 16:9. What this means is that the screen’s width will almost double its length, providing a viewing area comparable to a movie screen and more similar to the human eye perspective.

 

Digital technology implies the reduction of data to just 1s and 0s, translating it to the same language computers use. This makes signals easier to manipulate using computer technology in terms of solving signal distortions.

 

Making image digital means that it can be compressed to take less space in the carrying system, which represents a very important option, since HDTV signals take five times more bandwidth than current analog signals (today’s standard uses around 720 pixels by 485 lines, while HDTV will be capable of up to 1920 pixels by 1080 lines). However, compressing might result in a loss of image quality, a fact that appears contradictory with the concept of HDTV. It must be clear then that HDTV is a only subcategory of digital television; digital television in general requires only the reduction of information to 1s and 0s, but HDTV implies by definition a better picture quality.

 

Finally, television today transmits interlaced images, which means that the camera takes two snapshots of the scene within the same frame. On the first scan, even number lines are contained, while odd lines are contained in a second scan; this produces high brightness on the TV screen. HDTV provides the possibility of using progressive scanned images, in which one frame contains all the lines in their proper order. As we will see later, no standard has been yet defined.

 

THE INDUSTRY OF HIGH DEFINITION TELEVISION

The NTSC (National Television System Committee) has established the television standards we have available today (1998) in the US. However, new standards are being set by the Advanced Television System Committee (ATSC). These imply the transition from analog to digital and provide more versatility in the system, since they support more picture formats, which go in aspect ratio from 4:3 (currently used) to 16:9 (HDTV), picture size from 640*480 to 1920*1080, and both interlaced and progressive frame rates. Even though ATSC is more versatile, it still requires new standards that affect every player in the industry.

 

Broadcasters will have to produce pictures in digital format instead of traditional analog. This means that they will have to invest in either upgrading their systems or acquiring new ones. According to Charlie Jablonsky, NBC’s VP of broadcast and Network, NBC has been investing in converting to digital since early 1990s, and each of the four stations that are intended to begin digital transmissions by November 1998 is spending between $2 million and $3 million to convert to digital (as reported in Daily Variety, 6 April 1998). They will also have to make their equipment to the new aspect ratio of 16:9.

Because HDTV signals take five times more wave length than analog, carriers need also to make an adjustment in their equipment to provide greater bandwidth in their systems. Again, this means a major investment on their part.

 

Manufacturers are required to provide broadcasters and carriers with equipment compatible with the new technology. Sony, Panasonic and Mitsubishi already have cameras, production switchers and encoders for transmitting HDTV, while Silicon Graphics, Sun Microsystems, Tektronix and Hewlett-Packard are providing the servers and MPEG test equipment (Motion Picture Expert Group, which indicates standards for digitizing video).

 

Manufacturers might seem like the big winners in this game, since they will have a new and more expensive market, but they still have to invest in research and development, especially when standards are still to be set. However, it is likely that those who finally set the standard are going to be ahead of the market in the early stages.

 

Regardless of the lack of standard, it is most likely that soon all TV signals in the US will be transmitted in digital form, and public policy plays a big role here. In 1996, the FCC approved the digital TV standards with its eighteen possible formats, and by 1997 it assigned digital channels to existing broadcast stations so they can transmit in analog and digital simultaneously until analog is finally phased out early in the 21st. century. By 1 May 1999, all four networks in the top ten markets are supposed to be transmitting in both formats, and by 1 November 1999 this will be required for the top thirty markets. The idea of the FCC ruling is that by the year 2003 all analog channels will be duplicated by a digital channels, so finally analog could be turned off completely by 2007.

 

TV watchers seem like passive players in this change, and it is likely that they will have no other option but to acquire the equipment to adapt to the digital format. In the beginning only those with deep pockets and driven by technology will be willing to pay for a HDTV set, since their prices are supposed to range from $5,000 to $10,000.

 

APPLICATIONS OF HIGH DEFINITION TELEVISION

The most important feature of HDTV is that it will enhance the TV watching experience, making it similar to going to a movie theater but with a very high image definition and high sound quality.

 

However, since information is transmitted in digital signals, HDTV might be looked at from a convergence perspective. Using compression technology, multichannel television could be broadcasted using compression technology, providing with an ever wider variety of options for the viewer than those in 1998. Digital signals could also be used to 'distribute data streams for transactional services, interactive advertising,' (Baldwin et al. 1996:274) as well as to transmit faxes, e-mails and pagers.

 

Even though it can be argued that current TV users are seeking for more viewing options and interactive TV, this alternative seems more attractive to broadcasters who can put more information on the air and seek out market segmentation; and it is definitively attractive to TV equipment manufacturers because they are actually expanding their business.

 

DRIVING FORCES AND CONSTRAINTS

Broadcasters, carriers, manufacturers and public policy seem to be pushing HDTV to the viewers’ living room. Because it implies a digital signal, broadcasters might look at it as a way of creating market segmentation, since by compressing the information even more channels than today (1998) will be available. For carriers it could appear as a means for convergence, because besides traditional TV images and sound, digital technology allows the transmission of all kind of data (i.e. fax and e-mails as explained). For manufacturers it implies a way of increasing its sales, since new equipment is going to be required by broadcasters, carriers and viewers.

 

The importance of these players might explain the support that public policy is giving to digital television - the base for HDTV. According to FCC plans, by 2007 digital television will take over analog systems.

 

TV viewers do not seem to represent a very active role for the appearance of HDTV, but will definitively have to adapt to the new system. It is possible that viewers would appreciate more channels and better quality, but there seems to be no objective indicator that they are actually asking for it. However, public policy has given consumers the next nine years (to the year 2007) to react to this format.

 

Costs are a very important issue for HDTV, since all the players will have to make important adjustments to provide (broadcasters and carriers) or receive the service. But since such strong forces are pushing in favor of this format, conversion to digital TV appears unstoppable. Nevertheless, since there is no specific standard for digital TV, it is not quite sure if HDTV is the future. So far there are 18 possible formats for digital TV, but only a few have HDTV requirements (16:9 aspect ratio and a significant higher resolution). It is still to soon too predict a forecast and it will be an answer that only time provide.

 

OPPORTUNITIES, PROBLEMS AND PROSPECTS

WHERE IS HDTV HEADED?

As stated, HDTV is just one of the alternatives for digital TV and there are many things to be tried and said before one of the formats is established as a standard. But considering the driving forces behind digital TV, it is more likely that the one that is more cost effective and represents the most advantages for broadcasters and carriers will be the one to succeed.

 

The consumer is the final target of new technology, and in this case greater forces are pushing the technology towards him. However, HDTV might represent a way of attracting consumers to digital television: since they would have to upgrade their systems anyway, wouldn’t it be nice if they got not just more channels but also better picture quality?

 

Consumers appear to be tied up with whatever standard is decided by the other players, but if HDTV is used to increase the appeal of digital TV, the transition from analog to digital could be done more smoothly.

 

REFERENCES

 

Allan, E. (1998) ‘Sony plugs in to coordinates of new formats’, Daily Variety, 6 April.

 

Argy, S. (1998) ‘Tracing the evolution of brave, new TV’, Daily Variety, 6 April.

 

Baldwin, T. F., Mc Voy, D. S. and Steinfield, C. (1996) Convergence: Integrating Media, Information & Communication, SAGE Publications.

 

Bhatt, B., Birks, D. and Hermreck, D. (1997) ‘Digital Television: making it work’, Spectrum, October.

 

Dunkin, A. (1998) ‘Video: eye popping TV - but it will cost you’, BusinessWeek, 16 February.

 

Grove, C. (1998) ‘Transmitting mixed signals’, Daily Variety, 6 April.

 

Hardesty, M. (1998) ‘Broadcasters buckle up for November convergence’, Daily Variety, 6 April.

 

'Reinventing Broadcasting.' Available HTTP: http://www.analog2digital.com/technology/.

 

Richer, M.S. (1996) Keynote speech, International Workshop on HDTV'96, Los Angeles, CA: online. Available HTTP:http://www.atsc.org/Hdtv'96b.html.

 

Walker, G.M. 'HDTV roll-out - been there, done that', World Broadcast News: online. Available HTTP:http://www.analog2digital.com/blueprints/.

 

 

Back to Home Page