Glossary Terms Beginning M

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M4: Multi-Media Mini-M: INMARSAT successor to Inmarsat-B System, offering smaller sized terminals with enhanced data capabilities. Also called Global Area Network.
Magnetic: North direction towards which a compass needle will ordinarily point when influenced by the magnetic field of the Earth.
Margin: Amount of signal in dB by which the satellite system exceeds the minimum threshold required for operation.
Matrix: Switching router that can connect any input source to any output destination.
MB: Megabyte: 1 million bytes per second (1 × 106 bytes per second).
Mbaud: Megabaud: 1 million symbols per second (1 × 106 symbols per second).
Mbps: Mega-bits per second: 1 million bits per second (1 × 106 bits per second).
MCPC: Multiple channels per carrier.
MCR: Master control room.
MES: Mobile earth station.
MHz: Megahertz: unit of frequency equal to 1 million cycles per second or 1 × 106 Hz (1000 000 Hz).
Microwave: Refers to frequencies typically in the range of 2–30 GHz.
Mix-minus: The transmission to the remote location of the output of the studio minus the contribution from the remote location; see Cleanfeed.
Modem: MODulator/DEModulator: device that transmits and receives data.
Modulation rate: Modulated symbol rate.
Modulation; modulator: Process of manipulating the frequency or amplitude of a carrier in relation to a signal; device which combines a ‘message’ signal with a high-frequency carrier signal for transmission.
Motion JPEG: Method of using JPEG coding techniques to compress and transmit television pictures.
Mount: Mechanical assembly upon which the SNG antenna is mounted, complete with all necessary mechanical adjustment controls.
MPEG: Motion Pictures Expert Group.
MPEG-1: Video compression standard for non-interlaced, computer-type data streams. Typical MPEG-1 video compression goes up to 100:1 for images composed of 352 pixels (picture elements) × 288 lines at a refresh rate of up to 30 frames per second.
MPEG-2: Standard covering the compression of data (coding and encoding) for digital television, derived from MPEG-1 and defined for interlaced broadcast TV. It provides improved picture quality, higher resolution and additional features such as scaleability.
ms: Millisecond: one thousandth of a second (1 × 10–3)
MSD: Medium speed data: usually for INMARSAT purposes; equivalent to a data rate of 9.6 kbps.
MSps: Mega-symbols per second: measurement of data rate – 1000 000 symbols per second (1 × 106 symbols per second).
MSS: Mobile-Satellite Service: ITU designation.
Multilateral: Transmission from one origin to a number of destinations simultaneously.
Multiple channels per carrier: MCPC: where multiple programme signals are combined onto one carrier signal and uplinked.
Multiplexer: Combines a number of separate signals into one signal for simultaneous transmission over a single circuit.
MUSICAM: Masking pattern adapted Universal Sub-band Integrated Coding And Multiplexing: digital audio compression standard.