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===Features=== [[File:ISDB-T CH Seg Prog allocation.svg|thumb|250px|Treeview of ISDB-T, channels, Segments and arranging multiple program broadcasting.]] ISDB-T is characterized by the following features: * ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) in Japan use [[Ultra high frequency|UHF]] 470 MHz-710 MHz, bandwidth of 240 MHz, allocate 40 channels namely channels 13 to 52 (previously used also 710 MHz-770 MHz, 53 to 62, but this range was re-assigned to cell phones), each channel is 6 MHz width (actually 5.572 MHz effective bandwidth and 430 kHz guard band between channels). These channels are called "physical channel(η©ηγγ£γ³γγ«)". For other countries, US channel table or European channel table are used. * For channel tables with 6 MHz width, ISDB-T single channel bandwidths 5.572 MHz has number of carriers 5,617 with interval of 0.99206 kHz. For 7 MHz channel, channel bandwidth is 6.50 MHz; for 8 MHz 7.42 MHz. * ISDB-T allows to accommodate any combination of HDTV (roughly 8 Mbit/s in H.264) and SDTV (roughly 2 Mbit/s in H.264) within the given bitrate determined by the transmission parameters such as bandwidth, code-rate, guard interval, etc. Typically, among the 13 segments, the center segment is used for [[1seg]] with QPSK modulation and the remaining 12 segments for the HDTV or SDTV payloads for 64QAM modulation. The bitstream of the 12 segments are combined into one transport stream, within which any combination of programs can be carried based on the [[MPEG transport stream|MPEG-2 transport stream]] definition. * ISDB-T transmits an [[High-definition television|HDTV]] channel and a mobile TV channel '''[[1seg]]''' within one channel. 1seg is a mobile terrestrial digital audio/video broadcasting service in Japan. Although 1seg is designed for mobile usage, reception is sometimes problematic in moving vehicles. Because of reception on high speed vehicle, [[Ultra high frequency|UHF]] transmission is shaded by buildings and hills frequently, but reported well receiving in [[Shinkansen]] as far as run in flat or rural area. * ISDB-T provides interactive services with data broadcasting. Such as [[Electronic program guide|Electronic Program Guides]]. ISDB-T supports internet access as a [[return channel]] that works to support the data broadcasting. Internet access is also provided on mobile phones. * ISDB-T provides [[single-frequency network|Single-Frequency Network]] (SFN) and [[on-channel repeater]] technology. SFN makes efficient utilization of the frequency resource (spectrum). For example, the Kanto area (greater Tokyo area including most part of Tokyo prefecture and some part of Chiba, Ibaragi, Tochigi, Saitama and Kanagawa prefecture) are covered with SFN with roughly 10 million population coverage. * ISDB-T can be received indoors with a simple [[indoor antenna]]. * ISDB-T provides robustness to [[multipath interference]] ("ghosting"), [[Co-channel interference|co-channel analog television interference]], and [[electromagnetic interference]]s that come from motor vehicles and power lines in urban environments. * ISDB-T is claimed to allow HDTV to be received on moving vehicles at over 100 km/h; [[DVB-T]] can only receive [[SDTV]] on moving vehicles, and it is claimed that [[ATSC Standards|ATSC]] can not be received on moving vehicles at all (however, in early 2007 there were reports of successful reception of ATSC on laptops using USB tuners in moving vehicles).
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