Glossary - M
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Mail Server - A computer responsible for processing and/or storing e-mail. It is the electronic equivalent of a post office. E-mail accounts exist on a mail server, where e-mail messages are stored until retrieval by the e-mail client.
Main Trunk - The major link from the headend to feeder lines.
Master Antenna Television (MATV) - Antenna and distribution system which serves multiple dwelling complexes such as hotels, motels and apartments.
Master Headend - A headend that collects television program material from various sources by satellite, microwave, fiber, and other means, and distributes this material to Distribution Hubs in the same metropolitan or regional area. A master headend MAY also perform the functions of a distribution hub for customers in its own immediate area.
Media Gateway Controller (MGC) - An MGC is the overall controller function of the public switched telephone network (PSTN) gateway. It receives and mediates call-signaling information between the PacketCable(tm) and the PSTN domains, and it maintains and controls the overall call state for all calls.
MegaHertz (MHz) - One million cycles per second.
Microsecond - One millionth of a second.
Microsoft Networking - The Microsoft standard for interconnecting Windows-based PCs on a LAN which uses the Client for Microsoft Networks.
Microwaves - High-frequency radio waves used for telecommunications transmission. Line-of-sight, point-to-point transmission of signals at high frequency, usually above 890 MHz. Many cable television systems receive some television signals from a distant antenna location with the antenna and the system connected by microwave relay. Microwave frequencies require direct line-of-sight to operate. Trees and buildings distort or block the signal.
Microwave Oscillator - A device used to generate a microwave signal. It consists of two parts: a resonator to control the frequency of the microwave signal and an active device to generate the power.
Mid Band - The part of the frequency band that lies between television channels 6 and 7, received by the FCC for air, maritime and land mobile units, FM radio and aeronautical and maritime navigation. Mid-band frequencies, 108 to 174 MHz, can also be used to provide additional channels on cable television systems.
Mid Split - A frequency division scheme that allows bi-directional traffic on a single coaxial cable. Reverse channel signals propagate to the headend from 5 to 108 MHz. Forward path signals go from the headend from 162 MHz to the upper frequency limit. The duplex crossover band is located from 108 to 162 MHz.
Miles of Plant - The number of cable plant miles laid or strung by a cable system.
Mode - The path a photon takes in going from one end of an optical fiber to another.
Modem - A data communications device. Modem is a combination of two words, modulate and demodulate. Strictly speaking, a modem is a device that accepts a digital signal, then converts or modulates it into an analog signal that another modem can convert back, or demodulate into digital form again. A modem's speed and dependability are adversely affected by electro-magnetic interference, or static.
Modulation - When some characteristics of an electromagnetic wave are deliberately changed or manipulated for the purpose of transmitting information.
Modulator - The electronic equipment required to combine video and audio signals from a studio and convert them to radio frequencies (RF) for distribution on a cable system. Also, a very low-powered television signal generator used to provide signals for distribution on a cable television system
Monitor Plus - A spot monitoring service provided by Nielseon which records both local broadcasts and national cable commercial activities.
Mouse - A hardware pointing device used to control the movement of an on-screen cursor. The mouse buttons are then used to select items on the screen.
Moving Picture Experts Group (MPEG) - A voluntary body, which develops standards for digital, compressed moving pictures and associated audio.
Multicast - A multicast is a message that is sent out to multiple devices on the network by a host.
Multi-path - Copies of the desired signal that have arrived at the antenna after bouncing from objects between the signal source and the antenna; these signals can either cancel or reinforce each other.
Multiple Dwelling Units (MDU) - Apartment buildings and condominiums.
Multiple (cable) Systems Operator (MSO) - A company that operates multiple cable systems.
Multiplexer - A device that allows several users to share a single circuit. It funnels different data streams into a single stream. At the other end of the communications link, another multiplexer reverses the process by splitting the data stream back into the original streams.
Multiplexing - The potential transmission of several feeds of the same cable network with the same programming available at different times of the day. This is seen as one possible use of the additional channel capacity that may be made available by digital compression. Multiplexing is also used by some cable networks to mean transmitting several slightly different versions of the network, for example several MTV channels carrying different genres of music.
Multipoint Access - User access in which more than one piece of terminal equipment is supported by a single network termination.
Multipoint Connection - A connection among more than two data network terminations.
Must-Carry - The FCC rule requiring cable systems to carry all local broadcast television signals in their market.