Wired Broadband and Related Industry Glossary of Terms with Acronyms As of 13 June 2011 Compiled By: Conrad L. Young, Director, Broadband Technical Strategy



Download 6.44 Mb.
Page41/69
Date conversion08.07.2018
Size6.44 Mb.
1   ...   37   38   39   40   41   42   43   44   ...   69
Quad Flat No leads (QFN) Package shown with Microshield™ courtesy of RFMD
µW

Microwatt.
Micron

A unit of length equal to one-millionth of a meter. [Arr11]
Micro-reflections
Echoes in the forward or reverse transmission path due to impedance mismatches between the physical plant components. Micro-reflections are distinguished from discrete echoes by having a time difference (between the main signal and the echo) on the order of 1 microsecond. Micro-reflections cause departures from ideal amplitude and phase characteristics for the transmission channel. These problems can be corrected by equalization.


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.


Microwatt

One millionth of a Watt or 10-6 Watts. Abbreviated μW. [Fib111]
Microwave

A term denoting radio waves which are in the electromagnetic spectrum at frequencies approximately 1,000 MHz and higher. [Arr11]
Microwave Dish

A parabolic shaped antenna used for high-frequency RF signals. [Fib111]
Microwave Interference

Interference which occurs when an earth station aimed at a distant satellite picks up a second, often stronger signal, from a local telephone terrestrial microwave relay transmitter. Microwave interference can also be produced by nearby radar transmitters as well as the sun itself. Relocating the antenna by only several feet will often completely eliminate the microwave interference. [Sat07]
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.


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 Transmission

Communication systems using very high-frequency RF to carry the signal information. [Fib111]
Mid Band
The part of the frequency band that lies between television channels 6 and 7, reserved by the FCC for air, maritime and land mobile units, FM radio and aeronautical and maritime navigation. Mid-band frequencies, 108 to 174 MHz, also can 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.


milli

A prefix for one thousandth (10-3). [Arr11]
milliwatt

One thousandth of a Watt. [Arr11]
MIL-SPEC

Military Specification; performance specifications issued by the USA Department of Defense (DoD) that must be met in order to pass a published Military Standard (MIL-STD). [Fib111]
MIL-STD

Military Standard; standards issued by the USA Department of Defense (DoD). [Fib111]
MIME
Multipurpose Internet Mail Extensions

MIMO

Multiple Input Multiple Output; an antenna technology for wireless communications in which multiple antennas are used at both the source (transmitter) and the destination (receiver). The antennas at each end of the communications circuit are combined to minimize errors and optimize data speed. MIMO is one of several forms of smart antenna technology, the others being MISO (multiple input, single output) and SIMO (single input, multiple output). In conventional wireless communications, a single antenna is used at the source, and another single antenna is used at the destination. In some cases, this gives rise to problems with multipath effects. When an electromagnetic field (EM field) is met with obstructions such as hills, canyons, buildings, and utility wires, the wavefronts are scattered, and thus they take many paths to reach the destination. The late arrival of scattered portions of the signal causes problems such as fading, cut-out (cliff effect), and intermittent reception (picket fencing). In digital communications systems such as wireless Internet, it can cause a reduction in data speed and an increase in the number of errors. The use of two or more antennas, along with the transmission of multiple signals (one for each antenna) at the source and the destination, eliminates the trouble caused by multipath wave propagation, and can even take advantage of this effect. MIMO is an integral component of IEEE 802.11n architecture and deployments. [Sea04]
Minimum Bend Radius

The smallest radius an optical fiber or fiber cable can bend before increased attenuation or breakage occurs. [Fib111]
Mini-Slot
A mini-slot is an integer multiple of 6.25-microsecond increments.

Misalignment Loss

The loss of power resulting from angular misalignment, lateral displacement, and fiber end separation. [Fib111]
Mixer
A non-linear circuit that produces an output at the sum and difference frequencies of an applied fixed or variable oscillator called the LO, and the FR input signal of interest.

mm

Millimeter (10¯³ meters)

MMC
Multipoint Mixing Controller

MMDS
Multichannel Multipoint Distribution Service; a band of frequencies in the United States allocated for wireless television broadcast service. [Arr11] Or,
Microwave Multipoint Distribution Service; a digital wireless transmission system that works in the 2.2-2.4 GHz range. It requires line of sight between transmitter and receiver, which can be 30 or more miles apart. It was designed initially as a one-way service for bringing cable TV to subscribers in remote areas or in locations that are difficult to install cable. MMDS supports approximately 33 analog channels and more than 100 digital channels of TV. In late 1998, the FCC opened up the technology for two-way transmission, enabling MMDS to provide data and Internet services to subscribers. [PCm11]

MMDS
Multipoint Microwave Distribution System; a radio alternative to cable television. Sometimes shortened to
MDS. [Fre11]


MMI
Man-Machine Interface

MoCA™
Multimedia Over Coax Alliance. Short for
Multimedia over Coax Alliance, MoCA is a standards organization that supports a technology to provide the backbone for home digital entertainment networks. For the end-consumer, a MoCA solution includes a retail set-top box solution that works where your TV works and enables you to link entertainment devices in multiple rooms using existing coaxial cable wiring. MoCA supports streaming media, including audio, SDTV and HDTV and provides a clean dedicated shielded medium. It coexists with CATV and terrestrial services and also supports content protection. [Web11] Links to SCTE sponsored primers on MoCA™:

http://www.scte.org/mmpres/primer/MoCAp1/

http://www.scte.org/mmpres/primer/MoCAp2/

http://www.scte.org/mmpres/primer/MoCAHome/

http://www.scte.org/mmpres/primer/MoCA2/
Modal Noise

Noise that occurs whenever the optical power propagates through mode-selective devices. It is usually only a factor with laser light sources. [Fib111]
Mode
The path a photon takes in going from one end of an optical fiber to another. Or, a single electromagnetic wave traveling in a fiber. [Fib111]


Mode Coupling

The transfer of energy between modes. In a fiber, mode coupling occurs until equilibrium mode distribution (EMD) is reached. [Fib111]
Mode Evolution

The dynamic process a multilongitudinal mode laser undergoes whereby the changing distribution of power among the modes creates a continuously changing envelope of the laser’s spectrum. [Fib111]
Mode Field Diameter

A functional representation of an energy carrying region of the fiber. [Arr11] Also, a measure of distribution of optical power intensity across the end face of a single-mode fiber. [Fib111]
Mode Filter

A device that removes higher-order modes to simulate equilibrium mode distribution. A mode filter is most easily constructed. [Fib111]

Mode Filter Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/m


Mode Scrambler

A device that mixes modes to uniform power distribution. [Fib111]

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. Process by which signals are transformed to represent information (or data). Generally uses different frequencies to transmit data (FM). See also QAM.

Modulation Index



In an intensity-based system, the modulation index is a measure of how much the modulation signal affects the light output. It is defined as follows:

m = (highlevel - lowlevel) / (highlevel + lowlevel) [Fib111]
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. Also, a device that imposes a signal on a carrier. [Fib111]

Molniya

The Russian domestic satellite system which operated with highly elliptical satellites which overlooked the high latitudes of the territories of the USSR. [Sat07]
Monitor

1) a CRT that receives its signal directly from a VCR, camera, or separate TV tuner for high-quality picture reproduction. 2) A device used for the real-time temporary display of computer output data. 3) Software or hardware that is used to scrutinize and to display, record, supervise, control, or verify the operations of a system. [Fib111]
Monitor Application (MA)
The monitor application is a special unbound application with access to a privileged API set that manages the execution of all applications in the receiver.


Monitor Plus
A spot monitoring service provided by Nielsen which records both local broadcasts and national cable commercial activities.

Monochrome



Monochrome is a term used to describe black and white televisions. It can be broken down into “mono” meaning one and “chromatic” which means color. It is literally “one color”. This is because black and white cathode ray tubes are painted with white phosphors only. Painting the white phosphors with the electron beam makes them give off white light, and by switching off the beam a black effect is achieved. Black and white is a bit of a misnomer then as there is really only one color differential on a monochrome screen. A better name than “black and white” would be “light and dark”. [Glo07]
Monomode
All photons take the same path down the center of the core of an optical fiber. Also Single-mode Fiber.

Moore’s Law



A prediction for the rate of development of modern electronics. It states that the density of information storable in silicon roughly doubles every year. Or, the performance of silicon will double every eighteen months, with proportional decreases in cost. For more than two decades this prediction has held true. Named after Gordon E. Moore, physicist, cofounder and chairman emeritus of Intel Corporation. [Fib111]
MOSFET

Metal-Oxide Semiconductor Field-Effect Transistor; pronounced ‘MAWS-feht’, is a special type of field-effect transistor ( FET ) that works by electronically varying the width of a channel along which charge carriers ( electrons or holes) flow. The wider the channel, the better the device conducts. The charge carriers enter the channel at the source (denoted by “S” or “s”), and exit via the drain (denoted by “D” or “d”). The width of the channel is controlled by the voltage on an electrode called the gate (denoted by “G” or “g”), which is located physically between the source and the drain and is insulated from the channel by an extremely thin layer of metal oxide. [Wha10]

MOSFET Diagram courtesy of http://www.ustudy.in/sites/default/files/images/MOSFET.GIF


1   ...   37   38   39   40   41   42   43   44   ...   69


The database is protected by copyright ©dentisty.org 2016
send message

    Main page