Development of Evolved Mobile Satellite Communications System; WIDESTAR II

In April 2010, NTT DOCOMO began WIDESTAR II, mobile satellite communications service (MSS) covering all of the Japan landmass and the surrounding maritime area. WIDESATR II is the next stage in the evolution of the Japanese domestic MSS system and is the successor to WIDESTAR, using four beams of the N-STAR c/d geostationary satellites. The new WIDESTAR II system provides all of the previous WIDESTAR services and higher speed data communications at a lower cost. Base station equipment and mobile stations were newly developed, and core node equipment was efficiently developed to add only functions specific to MSS. The IP multimedia subsystem (IMS) and other general-purpose IP technologies were incorporated as the software is commonly used in the MSS and 3G/Long Term Evolution (LTE) cellular system. WIDESTAR II can provide diverse high-speed MSS services.