Correspondence from ABU Researchers

Correspondence from ABU Researchers
I am a research engineer from the Technical Research Institute of the KBS (Korean Broadcasting System, Korea). As a visiting researcher from an ABU participating institution accepted by the NHK Science & Technical Research Laboratories, I am engaging in research concerning the Japanese digital terrestrial broadcasting system (ISDB-T). I am here for a one-year term that started in June of last year. I was delighted to come to Japan when the opportunity was given to me to conduct full-scale research on the Japanese digital broadcasting system.
Since Korea has adopted the ATSC scheme for its digital terrestrial television broadcasting, and is likely to select the European DAB scheme for digital sound broadcasting, it cannot be said that we will have a direct connection to the ISDB-T system of Japan. However, when I joined the KBS in 1996, I had the opportunity to study the DAB system and gain an understanding of the outstanding characteristics of the OFDM modulation scheme. It is extremely meaningful to me to have been given the chance to learn directly about the systematic research, techniques used for digital broadcasting, as well as the ISDB-T transmission characteristic research through my residency.
During the first month after my arrival at the NHK Science & Technical Research Laboratories, my studies centered on past research papers, with an emphasis on deepening my understanding of the ISDB-T system. This was followed by the production of a computer simulation program to verify ISDB-T transmission characteristics. The verification of reception characteristics in a multipath environment has been achieved, and I am now working on fading environment programming to make mobile reception characteristic simulation possible. In the future, we are scheduled to conduct research concerning mobile reception technology and improvements on the viterbi decoder for inner coding using the produced simulation programs.
My research activity at the NHK STRL, as well as life in Japan, will always be a precious and unforgettable experience for me. 		I am a research engineer from the SARFT (the State Administration of Radio, Film, and Television) of China, an ABU participating institution.
I have been in the NHK STRL as a guest researcher since July of last year and am on a one-year stay. Presently, I am engaged in research on a PRS (Program Request Service) system utilizing the Internet.
First, I will briefly introduce the SARFT. The SARFT is the organization that sets standards for all of the broadcasters and public cable TV operators in China. One of the significant tasks of the SARFT is to examine the technical specifications of TV broadcasting and cable TV broadcasting schemes. A digital terrestrial broadcasting scheme and a distribution scheme for cable TV stations are both currently under examination. In China, the cable TV network is especially widely diffused, reaching more than 80 million households, centered in urban areas. Work is progressing of both networking between cable TV stations, and making facilities compliant for interactivity and the Internet, and this is, intensifying the demand for new service models and application technologies.
Since coming to the NHK Science & Technical Research Laboratories, I have conducted research in a wide range of areas, such as PRS systems using the Internet, based on the study of technological trends and discussions with research group members. I am constructing a framework to study PRS system operation by a software simulation method. In the future, using this software, I hope to develop a proxy server arrangement equipped with a cache function in order to provide efficient PRS services, along with the algorithms, based on various traffic model assumptions, and taking consideration of an Internet access model, viewer preferences, etc., together with an analysis of network structure and service quality.
I am extremely grateful for this opportunity to perform research at the NHK STRL. The experience I gain during this residency will be a great asset in my future career as a researcher.
Yim Zungkon,
Visiting Research Engineer, Digital Broadcasting Networks Division 		Wang Kaiming,
Visiting Research Engineer, Advanced Audio & Video Coding Division