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Japan was the only country that uses a sole variant of digital terrestrial television (DTTV) platform called Integrated Services for Digital Broadcasting–Terrestrial (ISDB-T). As compared to other platforms such as Digital Video Broadcast–Terrestrial (DVB-T) in Europe, Africa, Australia, and selected Asian countries, Advanced Television Systems Committee (ATSC) in North and Central America, including South Korea and Taiwan, and Digital Multimedia Broadcast–Terrestrial (DMB-T) in China and Hong Kong [to be discontinued in the future?], including South Korea and Taiwan, ISDB-T uses a combined action of DVB-T and DVB-H assigned on UHF band, giving more robust and more flexible transmission. The aforementioned Japanese DTV platform was now currently adopted in South America, Philippines, and Maldives.
First generation ISDB-T transmission under a standard 6 MHz UHF TV channel bandwidth consists a total of 13 segments under 16QAM and 64QAM digital modulaton, 12-segment for full HD DTV content and one-segment for mobile DTV transmission. Second generation ISDB-T transmission designed for Super Hi-Vision (SHV) or 8K resolution (7680 x 4320) DTV broadcast, on the other hand, uses higher-level digital modulation such as 1024QAM and 4096QAM, compared to 256QAM used in second generation DVB-T transmission (DVB-T2). An actual structure of second generation ISDB-T transmission under 6 MHz UHF TV channel bandwidth—currently under development after the successful transmission prototype using two UHF channels in Tokyo in 2012—was still unknown.
An additional specific details of the said platform was not publicized in public, but only a known Japanese experts that invented the prototype were responsible to hold confidential development. As I guessed in my thought accordingly on the following illustration but not based on actual reliable sources, each segment of the total 12 segments on first generation ISDB-T may contain a small resolution at about 480 x 360 pixels running on conventional MPEG-2 video codec, forming a full HD content of 1920 x 1080 pixels when combined an entire segments in proper “tagging” of sequence of video image pieces just like solving a jigsaw puzzle.
The concept of a segmented 720p (6-segment 426 x 360 pixels) or 1080i (12-segment 480 x 360 pixels) digital video structure used in first generation ISDB-T transmission may be based on conventional standard definition (SD) video wall being rolled out in 1980s and 1990s, in which it consists of a specialized digital console in order to divide the original 525-line NTSC (480i) or 625-line PAL (576i) analog video resolution into a separate 16 set of frame details of respective 180 x 120 pixels or 180 x 144 pixels before projecting through a separate 16 sets of SD CRT projectors. That technique was the same with the recent demonstration of displaying 16 sets of 1080p digital video image consisting of an actual 16-set full HD video camera shooting scene to form an 8K resolution format in the middle of decade 2000s, for which it would be possibly reflect on this visionary posted on this blog.
One of the recent development of experimental 8K Super Hi Vision digital video signal as of May 2013 was the 17-row MPEG-H HEVC encoder circuitry board cabinet developed by Mitsubishi Electric together with NHK. (CLICK HERE TO DOWNLOAD IN PDF FORMAT FOR DETAILS) Each board from that unit may contain an encoded video with a resolution of 7680 X 256 pixels for rows 1 to 16 and 7680 X 224 pixels for row 17, and then they sandwiched to form an 8K resolution image. If ever the NHK together with ARIB and DiBEG would develop a final prototype of signal structure of second generation ISDB-T, I wish they should try this latest sample illustration as I thought to speculate as shown above, containing a total of 17 segments for 8K resolution, a 31.1 MHz segment containing AAC stereo audio codec, a 300 KHz one-segment (s0) containing 1080p digital video content, and 600 KHz segment containing (proposed prototype) Dolby 22.1 stereo surround audio codec under 6 MHz UHF TV channel bandwidth. If 8K broadcast would not be used, then second generation ISDB-T may accomodate (1) four subchannel 4K resolution for rows 1 to 16 and 720p resolution for row 17 or (2) sixteen subchannel 1080p resolution for rows 1 to 16 and 720p resolution for row 17.
How I wish they would develop an actual, final design of segmented 6 MHz UHF TV channel bandwidth of second generation ISDB-T transmission before the target year of 2020 when 8K broadcast would start. Whether my statement is either a fact or fallacy about first generation ISDB-T, and maybe a possibility about a second generation ISDB-T platform in reality, this blog is open to post their comment for a correction of facts as shown below.