MANILA, Philippines - As early as 2006, the National Telecommunications Commission (NTC) had already released a memorandum regarding their decision for our country’s switch from analog to digital TV broadcast. This switch is scheduled to take place on December 31, 2015. Some of you may ask, why make a switch? What is the difference?
Standard analog TV transmission is similar to radio transmission. It consists of a video signal transmitted on AM radio waves and its video signal transmitted via FM waves. These signals are sent over the air as “frequency and amplitude” modulation. As such, analog TV is susceptible to interference. It depends on the geographical location and how far the receiving TV is to the signal. Hence, sometimes you will notice a blurry or “snow or ghosting” transmission. With analog TV, image quality and resolution is restricted to the amount of bandwidth assigned to the TV channel. It is quite noticeable also how different the color quality is from one channel to another.
DTV or digital TV, on the other hand, is the sending of audio and video by digital signals. It is similar to how a computer data is transmitted. Just like analog, digital is likewise transmitted over the air. It is however, conveyed through “bits” of information similar to that of a computer file. “Ghosting” is eliminated in digital broadcast. It is like an “all or none” deal. The viewer either sees the video or sees nothing at all. With the same bandwidth size as that of analog, digital TV can provide a higher quality image or even High Definition (HDTV) signal requiring less bandwidth space. It can therefore permit more space for additional audio, video or text channels in the form of perhaps a surround sound, multiple language audio, etc. It is also worth mentioning that digital TV can broadcast programs in “true widescreen” format (16 x 9).When NTC released its memorandum in 2006, they initially decided to use and adopt the DVB-T or Digital Video Broadcasting - Terrestrial for terrestrial transmission in the Philippines. DVB-T is a European based standard for digital broadcast transmission. Soon, a year after, NTC then made an announcement to reconsider other standards to replace DVB-T. During that time, government-owned TV stations were already testing the ISDB-T. Integrated Services Digital Broadcast – Terrestrial or ISDB-T is a Japanese-based standard and according to Digital Broadcasting Experts Group, it is the most advanced international standard on digital terrestrial television broadcasting.
It started in Japan way back in December 2003 then Brazil followed soon after in December 2007. Countries like Peru, Argentina, Chile, just to name a few, also adopted the technology. - Len Amadora, dated 1 March 2011, 9:53 AM.Source: Manila Bulletin