In order to maintain high economic growing and country competition and promote the people's living standard, government devote to develop high technological business and furthermore, push Taiwan into a scientific island to make Taiwan turn a cheap manpower exporting country to a brainpower high technical exporting country. At present, Internet and electronic commerce, which are developed by government from several years ago are growing vigorously and becoming famous.Striding forward 2000 A.D., government makes great efforts to develop digital video communication systems and decide to totally spread analog television into digital television in the year 2005, especially, digital video communication systems is the trend of world high techniques. Therefore, our government arranges it to be the key point of developing techniques. We also believe that this techniques will be become an important role in the world.