B-MAC

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The simultaneous PAL transmission of all TV-picture elements and the multiplexed transmission of the TV picture elements with D2-MAC. PAL and D2-MAC Transmission.png
The simultaneous PAL transmission of all TV-picture elements and the multiplexed transmission of the TV picture elements with D2-MAC.
Simulated MAC signal. From left to right: digital data, chrominance and luminance Multiplexed Analogue Components transmission (simulation).jpg
Simulated MAC signal. From left to right: digital data, chrominance and luminance

B-MAC [1] is a form of analog video encoding, specifically a type of Multiplexed Analogue Components (MAC) encoding. MAC encoding was designed in the mid 80s for use with Direct Broadcast Satellite systems. Other analog video encoding systems include NTSC, PAL and SECAM. Unlike the FDM method used in those, MAC encoding uses a TDM method. B-MAC was a proprietary MAC encoding used by Scientific-Atlanta for encrypting broadcast video services; the full name was "Multiple Analogue Component, Type B".

Contents

B-MAC uses teletext-style non-return-to-zero (NRZ) signaling with a capacity of 1.625 Mbit/s. The video and audio/data signals are therefore combined at baseband.

User base (PAL/NTSC zones)

Technical details

MAC transmits luminance and chrominance data separately in time rather than separately in frequency (as other analog television formats do, such as composite video).

Audio and Scrambling (selective access)

See also

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<span class="mw-page-title-main">A-MAC</span>

In television electronics, A-MAC carries digital information: sound, and data-teletext on an FM subcarrier at 7 MHz. Since the vision bandwidth of a standard MAC signal is 8.4 MHz, the horizontal resolution on A-MAC has to be reduced to make room for the 7 MHz carrier. A-MAC has not been used in service.

<span class="mw-page-title-main">C-MAC</span>

C-MAC is the television technology variant approved by the European Broadcasting Union (EBU) for satellite transmissions. The digital information is modulated using 2-4PSK, a variation of quadrature PSK where only two of the phaser angles (±90°) are used.

<span class="mw-page-title-main">D-MAC</span>

Among the family of MAC or Multiplexed Analogue Components systems for television broadcasting, D-MAC is a reduced bandwidth variant designed for transmission down cable.

<span class="mw-page-title-main">D2-MAC</span>

D2-MAC is a satellite television transmission standard, a member of Multiplexed Analogue Components family. It was created to solve D-MAC's bandwidth usage by further reducing it, allowing usage of the system on cable and satellite broadcast. It could carry four high quality sound channels or eight lower quality audio channels. It was adopted by Scandinavian, German and French satellite broadcasts. The system was used until July 2006 in Scandinavia and until the mid-1990s for German and French sound channels.

<span class="mw-page-title-main">CCIR System B</span> 625-line analog television transmission format

CCIR System B was the 625-line VHF analog broadcast television system which at its peak was adopted by more than one hundred countries, either with PAL or SECAM colour. It is usually associated with CCIR System G for UHF broadcasts.

References

  1. Report 1074-1 - Satellite transmission of multiplexed analogue component (MAC) vision signals (PDF). ITU. 1990. p. 48.
  2. Conradie, D.G. (19 June 1988). "The SABC's TV/radio satellite distribution system". COMSIG 88@m_Southern African Conference on Communications and Signal Processing. Proceedings. pp. 51–55. doi:10.1109/COMSIG.1988.49301. ISBN   0-87942-709-4. S2CID   131163463 via IEEE Xplore.
  3. "8.3 Multiplexed Analogue Components Transmissions". happy.emu.id.au.
  4. "Scientific-Atlanta's PowerVu Technology Helping AFRTS Expand the Delivery of A Touch of Home to Military Abroad" (Press release). Atlanta, GA: Scientific Atlanta. PR Newswire . Retrieved 2014-05-29.