Digital TV Around The World
As with standard broadcast TV, the new hi-def disks and videos tapes, Digital TV around world is basically all messed up with a variety of standards, of which DVB is the oldest and most accepted, but will not be used in America!
America, Canada, Mexico and Taiwan are going, instead with ASTC (Advanced Systems Television Committee) method.
Japan has itís own standard with ISDB.
China is developing an experimental format called SBTVD.
While all of these make use of the same essential media formats, it is on the broadcasting end that makes things different and there are pros and cons for both systems.
DVB was designed with mobile viewing in mind, so that people in the UK with video IPOD type devices can watch TV on the bus or train. DVB uses a multiplexed broadcasting method that packs SDTV (Standard Digital Television) with HDTV (High Definition TV) so that a given TV set can lock on to either and then find either signal and decode it as permitted by the device. This method of broadcasting is less prone to interference from buildings, cars and airplanes, thus you can get a fairly reliable picture on the road or in your home. Nokia is a major maker of DVB-H devices designed for seeing digital TV on the road.
ASTC was designed with both rural and city broadcasts in mind by having a powerful signal. It was also designed to carry mixed media on the same spectrum, so that, for example, NBC TV could send out a program in analog NTSC (National Television Standards Committee) standard, which is what you have been used to seeing since about 1950, along with the same program in SDTV and HDTV. This way they can start using it now and still accommodate older TV set owners, new digital TV set buyers and those who are investing in the more expensive HDTV sets..
The European method requires completely new TV sets for DBV, although those TV sets are often equipped with regular tuners so they can still get the BBC in PAL (Phase Alteration Line) standard, which Europe has been using since the mid 1950s. But these signals must be broadcast by separate systems on different frequencies.
In the US, you see, we are going to close down the current broadcast frequencies by 2015 and sell them off. It is unclear what Europe is going to do.
Because the various elements of SDTV, analog TV and HDTV are placed within the spectrum and not locked to each other as they are in the DVB system you are going to face loss of signal when mobile and even at home if an airplane or building reflects the broadcast signal.
In Europe different variants of the DVB system are used for cable, direct TV and broadcast TV.
In America the current cable TV and direct TV systems will continue to work as they always have. You get a new SDTV or HDTV set and you simply connect your Direct TV box or digital cable box to the set as you would on any TV.
It is for your TV set purchase that this comes into play, with sets in North America being exclusively ASTC. Elsewhere in the world DVB sets with be exclusive, with some makers probably offering ASTC abilities as well, however this will be costly.
One of the factors, probably, in adopting ASTC in America is that it is a proprietary system with a variety of Patents covering aspects of the technology, while DVB is an open architecture system that does not require licensing or payments to Patent holders.
Also, ASTC was a Johnny come lately, with DVB on paper in 1990 and first broadcast in 1994.
America has, in fact, been on the tail end of HDTV for decades! Japan viewers have been seeing analog HDTV since the 1980s and British wide screen TV set owners have been seeing Pal Extra since before 1990.
HDTV in America only started around the year 2000 and by 2001 there were only about 20 shows in HDTDV. This year, almost every network show is in HDTV and by 2009 every local TV show will be in HDTV.
Because broadcasting comes under the supervision of Government, the US Congress and FCC got into the act back in the 1980 and tried to make a system that would be as compatible with current TV sets as color is on black and white sets.
In the 1990s they gave up on this ideal idea, largely because of the digital revolution which would force the world to give up the current TV technologies.
This kind of thing didnít happened with music or videos, thus the CD became king, the DVD became king and two off shore companies, JVC and Sony, got to fight it out over VHS and Betamax. Sony lost that one and the US didnít care because their people didnít own either company, but the stock investors were evenly split. All is fair in the NY stock exchange!
When push comes to shove, however, if you are well located in the city there is probably no difference between a DVB and ASTC broadcast that you can see if your eye or measure scientifically.
The problem is that if you relocated within this world, your TV set probably canít go with you!