Differences

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--- digital_television [2017/11/14 09:18] – [디지털 플랫폼: 물리적 경로] hkimscil
+++ digital_television [2020/11/06 21:44] – [Dital Broadcasting -- IPTV and all others] hkimscil
@@ Line 1: / Line 1: @@
-====== Dital Broadcasting -- IPTV and all others ======
+====== Analog Television ======
-reference. {{:databroadcastetri.pdf|ETRI 보고서}} PDF
+^ ^ NTSC  ^ PAL  ^
+| stands for   | National Television System Committee  | Phase Alternation by Line  |
+| Bandwidth  | 6 MHz  | 7 to 8 MHz  |
+| Vertical Freq  | 60 Hz  | 50 Hz  |
+| Horizontal Frequency  | 15.734 kHz  | 15.625 kHz  |
+| Lines  | 525 (480)  | 625 (576)  |
+| Field per sec. | 60  | 50  |
+| Frame((Analog TVs use a cathode-ray tube (CRT) to beam light against the backside of a screen. These tubes aren’t like projectors—they can’t fill up a screen in one go. Instead, they quickly beam light down from the top of a screen. As a result, though, the picture at the top of the screen starts to fade as the CRT beams light at the bottom of the screen. from https://www.howtogeek.com/428987/whats-the-difference-between-ntsc-and-pal/)) per sec. | 30  | 25  |
-Analog to Digital
+{{https://static.diffen.com/uploadz/thumb/f/ff/PAL-NTSC.svg/610px-PAL-NTSC.svg.png}}
-| A  |  D  | 비고  |
-| terrestrial broadcast (TB)  | digital TB   | free . . . \\  cf. [[wp>Aereo|Aereo antenna]]   |
-| CA  | @lightgreen: Digital CA  | 통신사 + 케이블 회사 \\ mobile + internet + tv + \\ music + tv/movie content service \\  \\ PP (TB 포함)와 함께 subscribers 확보  |
-| <del>satellite</del>  | @lightgreen: Satellite television  | :::  |
-|   | @lightgreen: IPTV  | :::  |
-즉, 어떤 contents를 어떻게 전달할 것인가가 앞으로의 과제.
-  * customization
-  * connected TV
-[[wp>Aereo|Aereo antenna]] . . .
+{{https://www.howtogeek.com/wp-content/uploads/2019/07/1-5.png.pagespeed.ce.goyY-Ja3_y.png}}
+====== Dital Broadcasting -- IPTV and all others ======
+reference. {{:databroadcastetri.pdf|ETRI 보고서}} PDF
 Conversion of analogue television signals to digital signals -> __sampling__
@@ Line 25: / Line 25: @@
     * robust signals
     * uses **less bandwidth**
-  * sending information
+그러나 영상 외에도 필요해지는 것
+  * sending (and receiving) information
     * via one channel: one-way channel, broadcast channel, forward path, or in-band channel, etc.
     * via two channel: two-way channel, interactional channel, **return path**, back channel or out-of-band channel, etc.