ITGS Syllabus

Thursday, April 05, 2007

Topic 211

Broadcast media: digital radio and television, electronic news, magazines and books by HeeJun Son

The term broadcast media means a wide variety of different communication methods such as radio, television, newspapers, Internet, magazines and any other materials supplied by the media and press. The audience may be adults or children depending on programs or magazines. The broadcasting media supplies lots of the latest and valuable information, for example daily news, interviews, advertisements, speeches, etc. The primary broadcast media in these days are: digital radio and television, electronic news, magazines and books.

Digital Audio Broadcasting (DAB) is a new transmission system bringing the benefits of digital to the world of radio. Analogue radio transmission system that we have been using is being replaced with DAB because DAB has more advantage and benefits to both listeners and broadcasting corporations. First of all, for DAB transmissions, there is no the hiss and fade (multipath interference) that can spoil analogue radio transmissions.

This is particularly good news for listeners who can now hear the latest news and sport without all the usual problems associated with Medium Wave reception. Second of all, DAB signals are also far less likely to be affected by adverse weather conditions or local sources of interference unlike FM radio system. Third, DAB technology allows broadcasters to transmit far more radio stations within the same comparable amount of radio spectrum compared to FM. The flexible nature of our national DAB radio mutliplex means that broadcasters can create secondary services. As well as music and speech - DAB transmissions also contain data information. A DAB set utilises a screen, on which various kinds of information can be displayed.

You must have listened or watched ABC, CNN, CBS, MSNBC, PBS, or FOX news once in your life. All of them publish the newest news articles on their websites as well as broadcasting through televisions. The published news articles on the Internet is called electronic news. It is very convenient to use this broadcast medium to get news since people can always easily find out and catch up what is happening in the world whenever they want.

Not only publishing news articles on their websites, but they also broadcast. Nowadays the trend of television is changing to Digital TV from analog TV. Digital television (DTV) is a telecommunication system for broadcasting and receiving moving pictures and sound by means of digital signals, in contrast to analog signals used by analog (traditional) TV. DTV uses digital modulation data, which is digitally compressed and requires decoding by a specially designed television set. Digital television has several advantages over traditional analog TV. The most significant advantage of DTV is that digital channels take up less bandwidth space, meaning digital broadcasters can provide more digital channels in the same space with the better quality.

Digital television also enables special services such as electronic program guides and multicasting, which is watching more than one program on the same channel. Digital television has a better image, audio quality, and reception than analog. But there has seen some problems with DTV because digital television picture technology is still in its early stages. Digital television images have some picture defects that are not present on analog television due to present-day limitations of bandwidth and the compression algorithms. When a compressed digital image is compared with the original program source, some digital image sequences may have distortion or degradation such as quantization noise, incorrect color, blockiness when high-speed motion is depicted, or a blurred, shimmering haze.


Blogger Vaibhav said...

i am doing this one... - Vaibhav

March 04, 2007 9:23 PM  

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