Telecommunications terms starting with M

413 terms

master station In a data network, the station that is designated by the control station to ensure data transfer to one or more slave stations.
master-slave timing Timing in which one station or node supplies the timing reference for all other interconnected stations or nodes.
mastergroup See group.
matched junction A waveguide component having four or more ports, and so arranged that if all ports except one are terminated in the correct impedance, there will be no…
matching gel See gel.
material absorption See absorption.
material dispersion See dispersion.
material dispersion coefficient [M(λ)] In an optical fiber, pulse broadening per unit length of fiber and unit spectral width, usually expressed in picoseconds per…
material scattering Of an electromagnetic wave, scattering that is attributable to the intrinsic properties of the material through which the wave is propagating.
matrixing The accomplishment of a color coordinate transformation by computational, electrical, optical, or by other means. [After IEEE 100] [After SMPTE]
matte An image or signal that represents or carries only transparent information that is intended to overlay or control another image or signal. [After SMPTE]
MAU Abbreviation for medium access unit.
maximal-ratio combiner A diversity combiner in which (a) the signals from each channel are added together, (b) the gain of each channel is made proportional to the rms signal…
maximum block transfer time The maximum allowable waiting time between initiation of a block transfer attempt and completion of a successful block transfer.
maximum calling area Geographic calling limits permitted to a particular access line based on requirements for the particular line.
maximum disengagement time The maximum allowable waiting time between initiation of a disengagement attempt and successful disengagement.
maximum justification rate Synonym maximum stuffing rate.
maximum keying frequency In facsimile systems, the frequency in hertz numerically equal to the spot speed divided by twice the X-dimension of the scanning spot.
maximum modulating frequency In a facsimile transmission system, the highest picture frequency that is required.
maximum stuffing rate In a bit-stream, the maximum rate at which stuffing bits can be inserted into the stream. Synonym maximum justification rate.
maximum time interval error (MTIE) The maximum error for all possible measurement intervals within the measurement period. [T1.101-1999]
maximum usable frequency (MUF) In radio transmission using reflection from the regular ionized layers of the ionosphere, the upper frequency limit that can be used for transmission…
maximum user signaling rate The maximum rate, in bits per second, at which binary information can be transferred in a given direction between users over the telecommunications system…
Maxwell's equations A set of partial differential equations that describe and predict the behavior of electromagnetic waves in free space, in dielectrics, and at…
Mbone Abbreviation for multicast backbone on the Internet. A part of the Internet designed to support IP multicasting by coordinating the transmission of…
MCC Mesoscale Convective Complex. A large MCS, generally round or oval-shaped, which normally reaches peak intensity at night.
MCM Multi-Chip Module. 178
MD5 (Message Digest Algorithm #5) The message digest algorithm used in PGP is the MD5 Message Digest Algorithm, placed in the public domain by RSA Data Security, Inc.
MDF Abbreviation for main distribution frame.
meaconing A system of receiving radio beacon signals and rebroadcasting them on the same frequency to confuse navigation.
mean power (of a radio transmitter) The average power supplied to the antenna transmission line by a transmitter during an interval of time sufficiently long compared with the lowest…
mean time between failures (MTBF) A measure of the reliability of an item. Defined as the total functioning life of an item divided by the total number of failures within the population…
mean time between outages (MTBO) In a system, the mean time between equipment failures that result in loss of system continuity or unacceptable degradation.
mean time to repair (MTTR) The total elapsed time for corrective maintenance divided by the total number of corrective maintenance actions during a given period of time.
mean time to service restoral (MTSR) The mean time to restore service following system failures that result in a service outage.
measured blocking threshold A value for measured blocking above which there is a statistically significant probability that the design blocking objective is not being met. [T1.
measured-rate service Telephone service for which charges are made in accordance with the total connection time of the line.
measurement period See performance measurement period.
mechanical splice Of optical fibers, a splice, i.e., permanent joint, accomplished by aligning the mating fibers in some kind of mechanical fixture.
mechanically induced modulation Optical signal modulation induced by mechanical means. Note: An example of deleterious mechanically induced modulation is speckle noise created in a…
mechanically intermateable connectors Connectors that are mechanically mateable, without creating mechanical damage, and without regard to attenuation properties.
Mechanism the means by which an effect or change is produced.
media converter Synonym medium access unit (MAU).
media stream A sequence of presentation units intended to convey some specific content. [T1.801.04-1997]
Mediation Mediation is an informal, voluntary method of resolving disputes, in which the parties in conflict meet with a trained, independent third party to come up…
mediation function In telecommunications network management, a function that routes or acts on information passing between network elements and network operations.
medium (pl.: media) 1. In plant tissue culture, a term for the liquid or solid formulation upon which plant cells, tissues or organs develop.
medium access unit (MAU) In a communications system, the equipment that adapts or formats the signal for transmittal over the communication medium.
medium frequency (MF) Frequencies from 300 kHz to 3000 kHz. See electromagnetic spectrum.
medium interface connector (MIC) In communications systems, the connector at the interface point between the bus interface unit and the terminal, i.e., the medium interface point.
medium interface point (MIP) In communication systems, the location at which the standards for the interface parameters between a terminal and the line facility are implemented.
medium-power talker A hypothetical talker, within a log-normal distribution of talkers, whose volume lies at the medium power of all talkers determining the volume…
medium-term bit error rate Bit error rate that can be encountered for relatively short time periods (e.g., minutes), due to temporary malfunctions of, for example, transmission…
megahertz (MHz) A unit of frequency denoting one million (106) Hz.
memory Data storage in the form of chips, or the actual chips used to hold data; storage is used to describe memory that exists on tapes or discs.
memory scavenging The collection of residual information from data storage. [INFOSEC-99]
menu A list of options, each of which performs a desired action such as choosing a command or applying a particular format to a part of a document.
MEO Medium Earth Orbit.
MERCAST Acronym for merchant-ship broadcast system.
merchant-ship broadcast system (MERCAST) A maritime shore-to-ship broadcast system in which the ocean areas are divided into primary broadcast areas each covered by a high-powered shore radio…
meridional ray In fiber optics, a ray that passes through the optical axis of an optical fiber (in contrast with a skew ray, which does not).
mesh network See network topology.
mesh topology See network topology.
mesochronous The relationship between two signals such that their corresponding significant instants occur at the same average rate.
message In the Java Message Service, an asynchronous request, report, or event that is created, sent, and consumed by an enterprise application and not by a human.
message alignment indicator In a signal message, data transmitted between the user part and the message transfer part to identify the boundaries of the signal message.
message authentication Determining that a message has not been changed since leaving its point of transmission, where: (a) the identity of the originator is verified, and (b)…
Message Authentication Code (MAC) A cryptographic checksum on data that uses a symmetric key to detect both accidental and intentional modifications of the data.
message body 1. For the single message format, the message words. 2. For the multiple message format, the parameter messages. [After T1.401-1998]
message broadcast An electronic-mail conference capability using data terminals. Note: Control can be maintained by the user or by the network.
message center See communications center.
Message Digest A cryptographic checksum, typically generated for a file that can be used to detect changes to the file; Secure Hash Algorithm-1 (SHA-1) is an example of…
message element 1. In e-mail, a specified portion of a message (e.g., the header, the body). [ANSDIT] 2.
message externals Information outside of the message text, such as the header, trailer, etc. [INFOSEC-99]
message feedback A method of checking the accuracy of transmission of data by sending received data back to the sending end for comparison with the original data that have…
message format A predetermined or prescribed spatial or time-sequential arrangement of the parts of a message that is recorded in or on a data storage medium.
message frame A frame that consists of the channel seizure signal, the mark signal, the message, the checksum word, and any possible filler marks. [T1.401-1998]
message handling system (MHS) In the ITU-T X.400 Recommendations, the family of services and protocols that provides the functions for global electronic-mail (e-mail) transfer among…
message heading In radio communications, the message part or parts that (a) precede the text, i.e.
message indicator [A] sequence of bits transmitted over a communications system for synchronizing crypto-equipment. Some off-line cryptosystems, such as the [. . .
message part In radio communications, one of the three major subdivisions of a message, namely the heading, the text, or the ending.
message register leads Terminal equipment leads at the interface used solely for receiving dc message register pulses from a central office at a PBX so that message unit…
message service Switched service furnished to the general public (as distinguished from private line service).
message signal unit (MSU) A signal unit that contains service information and signaling information fields and is retransmitted by the signaling link control if it is received in…
message switching A method of handling message traffic through a switching center, either from local users or from other switching centers, whereby the message traffic is…
message toll service Synonym message service.
message transfer agent (MTA) An OSI application process used to store and forward messages as described in the X.400 message handling system. [Bahorsky] Synonym Internet mail agent.
message transfer part The part of a common-channel signaling system that transfers signal messages and performs associated functions, such as error control and signaling link…
message type An assigned value used to identify the feature generating the message. [T1.401-1998]
message type code The mandatory one-octet field that uniquely defines the function and format of each ISDN user-part message. [T1.110-1987]
message unit A unit of measure for charging telephone calls, based on parameters such as the length of the call, the distance called, and/or the time of day. 2.
message word The smallest unit of data in the message body. This normally contains the actual feature data that a subscriber at the customer installation (CI) is…
messaging service In integrated services digital networks (ISDN), an interactive telecommunications service that provides for information interchange among users by means…
meta Of or relating to that portion of an HTML document that is not viewable by users through normal use of the browser window, but is readable by search…
meta certificate A certificate, issued to a signatory authority, that displays all co-signature requirements for its signatory certificates. [After X9.45]
meta name A meta key word that is incorporated in the head of an HTML document, and that includes the document's name and facilitates indexing for search engines.
meta-signaling VCs (vacant codes) The standardized vacant codes that convey meta-signaling information across a user-network interface (UNI). [T1.627-1993]
metallic circuit A circuit in which metallic conductors are used and in which the ground or earth forms no part.
metallic member A noncommunications metallic cable component such as a shield, vapor barrier, or strength member. [T1.316-1997]
metallic test access unit (MTAU) The functions associated with accessing a metallic facility for the purpose of testing.