| Popis: |
The World’s first satellite digital multimedia broadcasting (S-DMB) services has been launched by Mobile Broadcasting Corporation (MBCO) from October 20th, 2004 in Japan. The S-DMB system consists of both of the Geostationary Mobile Broadcasting Satellite (MBSAT) launched on March 13th, 2004, which is coowned by MBCO and SK Telecom, and terrestrial repeaters called Gap Fillers. In Japan it is now providing 40 channels of high quality audio, 8 channels of video and data services to mobile users nation-wide as the S-DMB services. The unique feature of this S-DMB service, called as “Moba-HO!” in Japan, is its high reception quality with small portable receivers at anytime and anywhere Nation-wide. In order to realize this “with Me” service, the MBSAT with high power transponders and a high gain 12m-diameter deployable antenna is used. The Gap Fillers, which transmit broadcasting signal to the areas where the satellite signal is blocked by obstacles, are also used in urban areas. The “System E” registered in ITU, which was innovated and submitted by Japan, has been applied to this satellite broadcasting system, which has employed CDM (Code Division Multiplex) technology and RAKE receivers for effective utilization of spectrum as well as mitigation of multi-path fading. This paper presents the performance of the current S-DMB services and its possible future applications such as disaster prevention media and/or an early warning system. |
