Digital Video Broadcasting - Term Paper Example

?Introduction:- The television was not invented in a one shot, rather it was an evolutionary process which began over a hundred years ago. The continuous advancement of technology and fierce competition among sellers of television drove the TV forward to produce what it is today (Bruin and Smits). The television is probably the most cost effective, common and popular electronic device in the world. It helps educate, entertain and update the general public about all the happenings that may concern them or otherwise. The television has gone through continuous evolution since its invention and in recent years the transition from analog to digital television has begun. The digital television is a much advanced system wherein users can disturbance free audio and visual signals while achieving much higher spectrum efficiency than analog televisions (WU, Hirakwa and Reimers) Evolution of Television:- European and North American inventors pioneered the TV. Television is a hybrid word coming from the Greek letter ‘ Tele’ meaning far, and Latin word ‘visio’ meaning sight. 1) Monochrome TVs: - These early generation televisions were mostly based on electrochemical systems. The screen had a small motor with a spinning disc and a neon lamp which gave a reddish orange picture comparable in size to a business card (Udelson). The system continued to evolve with the inception of a line system to improve the results of the TV. In 1937 the 405 line monochrome system, known then as the ‘HD’, was selected as the UK standard of television. By 1950, most European countries had the 625 scanning lines, 25 frame per second, TV system as standard. Meanwhile, plenty of experimentation was taking place in the USA, however, the Federal communications commission was not satisfied with the quality of the systems and work on development of the system continued. In 1942, the FCC endorsed the efforts of the National television systems committee and established a standard of 525 scanning lines with 60 frames per second. (Pitchard and Gibson) 2) The advent of Color TV: - During the 1940s, various color television systems were proposed and demonstrated in the United States. The first color television was developed in the early 1950s by the national television systems committee and submitted to the federal communication commission in 1953. Color TV was not successful in the United States until a decade of its introduction. Few color TVs were sold because they were expensive and there were not many programs televised in color. Time magazine even called color TV as ‘the most resounding industrial flop of 1956’. Slowly but surely, however, color TV started to thrive when color programs started to show up in abundance. European countries delayed adoption of color TVs and continuously worked to find alternative systems for the same function. Later on, the PAL(phase alteration line) systems were developed and adopted by numerous countries in Europe including the United Kingdom. (Udelson) Analog TVs and the march towards digitized broadcasting:- There were several projects that led to the shift from analog to digital tv systems. This march went on for years and involved various researches and experiments. Some of the key projects that led to this change include Japan Broadcasting corporation HDTV in Japan, Euraka EU 95 project and PALplus in Europe, and advanced compatible television in the United States (WU, Hirakwa and Reimers) 1) Japan NHK HDTV:- the NHK established the concept of High definition television as a system suitable for viewing television at around three times the picture height, having twice the horizontal and vertical resolution compared to the conventional TV systems and a wide aspect ratio. In the early 1980s, NHK had developed most of the production equipment necessary for producing HD TV programs. In 1983, the NHK developed a system called MUSE which compressed signal bandwidth from 30.1MHz down to 8.1MHz. Through frequency modulation, this allowed the transmission of HD signals by using only one transponder. HDTV production and distribution services improved rapidly in the 1990s driven by the need to supply programs for satellite MUSE services. 2) Eureka EU 95 and PALplus:- European countries were using two analog color TV systems namely the PAL and SECAM (Noll). HDTV was considered an excellent replacement for these two systems which will allow standardization across Europe. Multiplexed analog communication(MAC) was chosen as the standard technology underlying the development of HDTV. The MAC system was successfully used to develop HD pictures and colorful live broadcasts were shown from the Olympic games in 1992. The HD-MAC system, however, met its demise because it could not solve the problem of aspect ratio when broadcasting through satellite. PalPlus was in the limelight again and served as the savior. Key members of the palplus project were responsible for finding the digital video broadcasting system used in Europe(DVB). 3) US Advanced Television System: - The US broadcasters petitioned to the FCC, after the development of HDTV and DVB to establish an advanced television standard and allocated a spectrum over the air broadcasting. The FCC then formed the Advisory committee on advanced television service which oversaw the development of an advanced television system. The Digital Television System:- The above mentioned developments in Japan, Europe and the USA eventually led to the development of the digital television system. In digital television, through source coding, the video and audio information is compressed using the moving picture experts groups compression standard. This compression makes it possible to fix more than one program in the same channel video spacing. The digital video broadcasting project was started in 1993 when European broadcasters vowed to work together to create a completely digital broadcasting standard for Europe. This was a revolutionary change that kindled new developments that made the TV more mobile and easy to access than ever before. The Modern day TV:- The stream of developments mentioned above led to TV as we know it today. Through various technological advancements, not only do we see various channels on a single screen we are also able to pause live broadcasts, record TV to savor later, see TV on the go via the mobile and view channels from all across the globe. Today private TV broadcasters offer different services such as specific channels for their subscribers. With the advent of the internet, online TV is the new phenomenon that enables us to access our favorite TV channels from all across the world. Subscription to specific broadcasters results in HD tv programs online. It is fair to say that the age of cable tv is coming to a close and satellite tv via broadcaster subscription is taking over. Works Cited Bruin, R de and J Smits. "Digital Video broadcasting - technology, standards and regulations." 1998 (n.d.): Artech house, inc. Noll, A.Micheal. The Economics, technology and content of digital TV. 1999. Pitchard, D.H and J J Gibson. Television transmission standards in 'Standard handbook of broadcast engineering'. New York: McGraw Hill, 2005. Udelson, J. "The great television race: a history of american television industry." (1982): University of Alabama Press. WU, Yiyan, et al. "Overview of Digital television development worldwide." (2006): Yale University Press. Read More