An SCSA definition. The specific implementation of an operation for a class; code that can be executed in response to a request.


A measurement. A benchmark. You might measure your marketing program by applying the metric of how many mailing pieces you send out each day. You might measure the value of your web advertising by how many "click throughs" you get each day. You need metrics to see if you're succeeding. Metrics originally meant the application of mathematical analysis to a field of study ” for example, econometrics. In its current voguish sense, it is a hifalutin word for measurement. See also Service Level Agreement.

Metro Ethernet Network

MEN. Metro Ethernet Network is a way to connect buildings on the Internet like desktops within a building. Its advantages include relatively simple scalability, due to its packet-based technology. Standards compliant interfaces are available for data communication/telecommunication devices at line rates of 10/100/1000 Mbps, and the draft-standard for 10 Gbps has been ratified. An Ethernet- based Metropolitan Area Network is generally termed a Metro Ethernet Network. Some European service providers have also introduced MEN-like technology for Wide Area Networks. In enterprise networks, Metro Ethernet is used primarily for two purposes: connectivity to the public Internet and connectivity between geographically separate corporate sites - an application that extends the functionality and reach ability of corporate networks. See Metropolitan Area Network.

Metro Network

See Metropolitan Area Networks.

Metropolitan Area Network

MAN. A loosely defined term generally understood to describe a network covering an area larger than a local area network (LAN), but less than a wide area network (WAN). A MAN typically interconnects two or more local area networks, may operate at a higher speed, may cross administrative boundaries, and may use multiple access methods . While MAN is a data term, a MAN may carry data, voice, video, image, and multimedia data. The only true MAN technology is SMDS, which, in fact, is limited to the MAN.

Metropolitan Dial

The common rotary dial or touchtone pad that contains both numbers and letters. Dials and pads are also available without the letters. Presumably metropolitan areas required the letters because of multiple central office exchanges, but rural areas with few subscribers and only one CO, required just a few digits and no letters .

Metropolitan Fiber Ring

A metropolitan fiber ring is an advanced, high-speed local network that can also be used to connect businesses and residences directly to a long distance carrier's network, and provide alternatives to the local telecommunications services they have today. This definition, courtesy MCI.

Metropolitan Network

See Metropolitan Area Network.

Metropolitan Service Provider

See MSP.

Metropolitan Statistical Area

MSA. Sometimes known as SMSA (as in Standard MSA), MSAs are areas based on countries as defined by the U.S. Census Bureau that contain cities of 50,000 or more population and the surrounding countries . Using data from the 1980 census, the FCC allocated two cellular licenses to each of the 305 MSAs in the United States.


Mobile Station Application Execution Environment (GSM 02.57): a framework to ensure a predictable environment for third-party applications in GSM or UMTS handsets (ie the Mobile Station). MExE does this by defining different technology requirements called "classmarks". MExE classmark 1 is based on WAP, classmark 2 on PersonalJava and JavaPhone, and classmark 3 on J2ME CLDC and MIDP. Other classmarks may be defined in the future. MExE specifies additional requirements for all classmarks, for instance a security environment, capability and content negotiation, a user profile, user interface personalization, management of services and virtual home environment. A handset can support any number of classmarks.

Mezzanine Board

A printed circuit board that plugs directly into a another plug- in card. For example, a mezzanine card might plug into a VMEbus, CompactPCI or PCI card, which may be peripheral controller or CPU or just adapter card that connects the mezza- nine card to the target bus. Mezzanine boards are designed to be rugged so that they do not have to be bolted down.


  1. MultiFrame.

  2. MultiFrequency.


MK-E is a suffix to an FCC registration number, indicating the function of a system in accordance with its FCC registration. An MF-E is a Fully Protected Multi-Function (Hybrid) Key System, with "MF" denoting " Multi-Function ," and "E" denoting that the system will accept both rotary and tone signaling. See also Hybrid Key System, KF-E, PF-E and Registration Number.


Another name for a blue box. MF stands for multi-frequency. A blue box reproduced the telephone industry's multifrequency tones, which it used at that time for inband signaling. Hard- core phreakers called them MF-ers ” for multifrequency transmitters. The acronym was also understood to stand for "motherf***ers,"because they were used to f*** around with Ma Bell. These blue boxes no longer work because the phone industry has gone to out of band signaling. See SS7.


MFCR2 protocol is a signaling and control technique which is an alternative to ISUP (ISDN User Part) for call set-up . It's used in South America.


Abbreviation for Microfarad; one thousandth of a farad, the unit of measuring capacitance . The capacitor is a common electrical device that can store electric charges, and pass AC but not DC. Most phones use capacitors to disconnect the bell during conversations.


The Modified Final Judgment is the federal court ruling that set up the rules and regulations concerning deregulation and divestiture of AT&T and the Bell system. See Modified Final Judgment for a bigger explanation.


Million Floating point Operations Per Second. A measure of computing power usually associated with large computers. Also known as Megaflops.


Modified Frequency Modulation. An encoding scheme used to record data on the magnetic surfaces of hard disks. It is the oldest and slowest of the Winchester hard disk interface standards. RLL (Run Length Limited encoding) is a newer standard, for example.


MultiFunction Operations System. An AT&T term.


See Multi-Function Peripheral.


Multifunction Peripherals. A gadget you connect to your computer that can print, photocopy, fax and scan.


Multiple Frequency Shift Keying.


German for tone dialing. Stands for Mehrfrequenzverfahren.


Master Group .


Master Ground Bar, also called Main Grounding Busbar.


Sounds very well. Better than SIP or H

Media Gateway Control Protocol. In November 1998 Level 3 Communications, Inc. and Bellcore (now Telcordia Technologies) announced the merger of their respective technical specifications for a new protocol designed to bridge between the conventional circuit- switched PSTN (Public Switched Telephone Network and the emerging Internet Protocol (IP) packet-switched networks. The merged specification, Media Gateway Control Protocol (MGCP), represents a combination of the Internet Protocol Device Control (IPDC) specification developed by a consortium formed by Level 3 and made up of leading communications hardware and software companies, and the Simple Gateway Control Protocol (SGCP), developed by Bellcore and Cisco Systems. MGCP is a draft specification for a physically decomposed gateway, i.e., a protocol converter, the components of which may be distributed across multiple physically distinct devices. MGCP enables external control and management of data communications equipment operating at the edge of emerging multi-service packet networks. This equipment is in the form of Media Gateways (MGs), which terminate media streams from Switched Circuit Networks (SCNs), packetize the data in IP packets, and deliver the packets to the IP-based packet network. The Media Gateways act under the control of Media Gateway Controllers (MGCs), which handle their registration and the management of their resources. Signaling and control interfaces between the circuit and packet networks are the responsibility of Signaling Gateways (SGs). A draft of the MGCP specification was submitted in late 1998 to the SS7-Internet mailing list of the IETF (Internet Engineering Task Force), where it remains in draft form at the time of this writing (May 2000). The MGCP draft also was distributed to the European Telecommunications Standards Institute Telecommunications (ETSI), and the Internet Protocol Harmonization Over Networks (ETSI TIPHON) working group for review and modification. Megaco, designated by the ITU-T as H.248, is a variation on the theme of MGCP, supporting a broader range of networks, including ATM. See also DOSA, Media Gateway, Megaco, and Simple Gateway Control Protocol.


Multi Grounded Neutral. A single uninsulated grounded conductor. The currents in the three phases of the transmission line are never quite equal; the MGN carries the residual unbalance current. At many poles, the MGN is physically grounded to a groundrod at the base of the pole. See Joint Pole.


Message Generator Traffic Simulator.


Modified Huffman data compression method.


Mobile Home Function.


The unit of conductivity.


Message Handling Service. A program developed by Action Technologies (and others) and marketed by those firms and Novell to exchange files with other programs and send files out through gateways to other computers and mail networks. It is used particularly to link dissimilar electronic-mail systems. A company running e-mail on their internal LAN will dedicate one computer on the network to be a MHS machine. Every hour or so it will call MCI Mail, CompuServe, etc. and download e-mail messages for people and upload messages from people on the network. Once it has the messages downloaded it will distribute them to the people on the LAN the messages are destined for. See MHS Message Handling System.

MHS Enterprise

A messaging installation either on a local or corporate-wide level that uses MHS as its backbone between several messaging applications such as E-mail, scheduling, fax, workflow and more. Gateways are used to connect to X.400 systems, public carriers and mainframe systems.

MHS Message Handling System

An ISO standard Application Layer protocol that defines a framework for distributing data from one network to several others. It transfers relatively small messages in a store-and-forward manner (defined by ITU-T as X.400 and by ISO as MOTIS/Message-Oriented Text Interchange Standard). See MHS.


MIME encapsulation of aggregate HTML documents is a proposed standard that would, if deployed on the Internet, allow the easy attachment of complex Web pages ” or entire sites ” to an email viewer. According to InfoWorld, that means that all components of a Web site could be sent as attachments on a single e-mail and then reassembled with full integrity to produce a functional site for the end viewer, even if that viewer does not have Web access. For example, companies could "push" via email Web or intranet content ” as well as applications and software downloads ” to employees without giving those employees carte blanche Web access.


An abbreviation for Megahertz. One million Hertz. One million cycles per second. Used to measure band and bandwidth. See Band and Bandwidth. Megahertz is also used by the computer industry to mean millions of clock cycles per second, a measure usually applied to the computer's main microprocessor. Everything that happens in a computer is timed according to a clock which ticks millions of times every second. Higher MHz computers work faster than lower MHz computers. But megahertz is not an accurate measure of a microprocessor's speed. Other factors, such as wider data paths and the ability to execute more than one instruction per clock cycle, affect the actual speed of a microprocessor. Which is why a 100 MHz Pentium chip outpaces a 100 MHz Intel DX4 chip. When comparing the speed of one PC to another, there are other factors also, such as the amount and speed of the system's random access memory (RAM).


Mode Indicate/Mode Indicate Common, also called Forced or Manual Originate. Provided for installations where other equipment, rather than the modem, does the dialing. In such installations, the modem operates in Dumb mode (no Auto Dial capability), yet must go off hook in Originate mode to connect with answering modems.


Britain's domestic intelligence agency.


Media Interface Adapter. Converts electrical signals into optical signals and vice versa.


Management Information Base. MIB is a database of network performance information that is stored on a Network Agent for access by a Network Management Station. MIB consists of a repository of characteristics and parameters managed in a network device such as a NIC, hub, switch, or router. Each managed device knows how to respond to standard queries issued by network management protocols. To be compatible with CMIP, SNMP, SNMP-2, RMON, or RMON-2, devices gather statistics and respond to queries in the manner specified by those specific standards. Within the Internet MIB employed for SNMP (Simple Network Management Protocol)-based management, ASN.1 (Abstract Syntax Notation One) is used to describe network management variables. These variables , which include such information as error counts or on/off status of a device, are assigned a place on a tree data structure. MIB is used in X.400 electronic mail. Many managed devices also have "private" MIB extensions. These extensions make it possible to report additional information to a particular vendor's proprietary management software or to other management software that's aware of the extensions. See CMIP, Internet MIB Tree, MIB-2, RMON, RMON-2, SNMP.

MIB Attribute

An ATM term. A single piece of configuration, management, or statistical information which pertains to a specific part of the PNNI protocol operation.


The initial collection of objects and attributes defined by the TCP/IP (Transmission Control Protocol/Internet Protocol) standards community. MIB-I was elevated to Internet standard status in May 1990.


The expression MIB refers to the original SNMB MIB definition in IETF RFC 1157. The broader MIB-2 (RFC 1213) adds to the number of monitoring objects supported and is included in SNMP-2's MIB. However, SNMP-2s MIB (RFC 1907) is a superset of MIB-2.

MIB Instance

An ATM term. An incarnation of a MIS object that applies to a specific part, piece, or aspect of the PNNI protocol's operation.

MIB Object

An ATM term. A collection of attributes that can be used to configure, manage, or analyze an aspect of the PNNI protocol's operation.


  1. Microphone.

  2. Medium Interface Connector. FDDI de facto standard connector.

  3. A designation for a multiplex which interfaces between two DSIs and one DSIC circuit.

  4. Microwave Integrated Circuit - In the microwave industry, a hybrid using thin- or thick-film conductors and passive components on a ceramic substrate combined with chip- form active and passive components.


Michael is my favorite son, for an obvious reason. He is my only son (despite my best efforts, see "Claire"). Once Michael could not read what was in this dictionary. Now he disagrees with my definitions. Were he not so damnedly correct and so insufferably smart, I'd be annoyed. At 22, Michael is a senior at Dartmouth College where he's finishing an undergraduate degree that gives the words vagueness, uselessness and impracticality whole new meanings. As for concrete achievements, Michael got himself elected Student Body Vice-President ” the first time a freshmen had been elected in the long history of Dartmouth College. I was proud. He also bought himself a $130,000 apartment as a sophomore. And now as he's about to graduate, he's going to sell the apartment for $172,500. His real estate transaction. Good, eh? What I'm most proud of is Michael's remarkable maturity. I shudder to remember the disaster I was at 22. Trust me it was not pretty. Michael is different. He's a pleasure to be with. He seems to actually like his parents. There is no "generation gap," as there was in my time. Michael and I are close. He actually enjoys spending time with me. I know this. He told me so, (when "editing" ” actually censoring ” this definition). We have developed a great friendship based on mutual respect. Michael respects my ability to provide him with expensive toys. I respect his ability to find new, and ever more expensive toys for me to buy him. I'm hopeful our friendship, which honestly is based on a lot more than toys, can continue through the remainder of my life. I'm now 61. Michael is 22. Though I don't want to live my life through my kids , it wouldn't be hard. They are both destined for great achievements. See Claire for the other one, and Susan for the mother, who brought them up while I was off playing with technology and writing this dictionary. Some years ” when telecom is booming ” this dictionary even manages to pay a little of their college bills ” though not last year and I'm guessing not this year. Please help educate Michael and Claire. Tell your friends to buy copies of this dictionary.


Unit of space that a mouse moves, measured at 1/200th of an inch. The speed of a computer mouse, that is, the distance the cursor moves across the screen, as it relates to the movement of the mouse across the mouse pad, is officially rated in "mickeys."


Magnetic Ink Character Recognition. A process of character recognition where printed characters containing particles of magnetic material, are read by a scanner and converted into a computer-readable digital format.



Micro Cassette

Miniaturized version of the standard audio cassette.

Micro Channel

A proprietary bus developed by IBM for its PS/2 family of computers' internal expansion cards. Also offered by NCR, Tandy and other vendors . See ISA and EISA.

Micro Components

Miniaturized audio components that provide the benefits of traditional sized components in far less space.

Micro Farad

One millionth of a farad. This is the common unit for designation capacitance in electronics and communications.

Micro To Mainframe Link

The telecommunications path over which data between a microcomputer and a mainframe computer travels .

Micro To Mainframe Software

Software which provides the logic by which data can be transferred back and forth between a microcomputer and a mainframe computer.

Micro Trenching

See Microtrenching.


Microarchitecture is what semiconductor chip designers call their chip's inner workings. Microarchitecture performs five basic functions ” data access, execution, instruction decode and write back results. Microprcessors are typically measured in speed, i.e. cycles per second, which are called hertz. But the reality is that microachitecture also causes a chip to work faster or slower.

Microbend Loss

Loss in optical power created when a lightguide (i.e., optical fiber) is bent microscopically, i.e., so slightly that it cannot be seen with the naked eye. Mark Mauriello at Lucent described to me a microbend less as a small diameter bend that is equivalent to the bending of a fiber around a grain of sand. It causes loss at 1550 nm but not 1310 nm. In contrast, a macrobend loss is a large diameter bend equivalent to the bending of a fiber around your finger. It causes loss at both 1550 nm and 1310 nm. Microbends can be caused during the installation process, during packaging, or by mechanical stress due to water in the cable during repeated freeze and thaw cycles. See also Macrobend Loss.


A small company with a small market capitalization, which is defined as the share price times the number of shares outstanding. How small a microcap is depends on whom you're talking with.


A cellular radio cell that's smaller than a macrocell, and larger than a pico- cell . See Macrocell and Picocell.


A proprietary bus developed by IBM for its PS/2 family of computers, which it introduced in 1987. The bus was one of IBM's "weapons" against the disturbing increase in clone PCs ( disturbing to IBM). IBM figured that introducing a proprietary bus like the microchannel (called MCA for the MicroChannel Architecture), it could slay the clones or control them by charging large amounts of money to license the microchannel architecture. The microchannel, however, engendered a big yawn from consumers, who didn't at the time need its speed, nor its greater complexity, nor its higher cost. As the need to process large amounts of Windows' video information became more urgent in the late 1980s and early 1990s, so faster buses have become more critical. And two new buses, VL and PCI, have been created. For a fuller explanation, see ISA, EISA, PCI and VESA.


What's left in the bag when the big chips are gone.


  1. Programmed instructions that typically are unalterable. Usually synonymous with firmware and programmable read-only-memory (PROM).

  2. Translation layer between machine instructions and the elementary operations of a computer. Microcode is stored in ROM and allows the addition of new machine instructions without requiring that they be designed into electronic circuits when new instructions are needed.

Microcom Networking Protocol

The Microcom Networking Protocol, MNP, is a defacto standard protocol that provides error correction and data compression in dialup modems. The protocol's design allows for a broad range of services to be implemented, while maintaining compatibility among modems with different levels of MNP capabilities. For example, a modem capable of MNP Class 5 and Class 7 data compression can talk to a modem that lacks MNP data compression.

According to Microcom, MNP is an error correction protocol accepted by international standards authorities (ITU-T Rec. V.42). MNP offers a reliable and widely accepted method of correcting errors in transmissions over dial-up communications lines. MNP incorporates three different data compression methods, including the ITU-T recommendation, V.42bis.

Since its original definition, MNP has evolved through nine classes of enhancements. Of those nine classes, the first four provide error control and are in the public domain. Classes 5 through 7 may be licensed from Microcom. Currently MNP error control (Classes 2,3 and 4) has been adopted, along with the LAPM protocol, as mandatory elements of the Consultative Committee on International Telegraphy and Telephony (ITU-T) V.42 recommendation for modem error control.

An Overview Of MNP Service Classes

Class 1

This is the first level of MNP performance. MNP Class 1 uses an asynchronous byte-oriented half-duplex method of exchanging data. MNP Class 1 implementations make minimal demands of processor speeds and memory storage. MNP Class 1 makes it possible for devices with few hardware resources to communicate error-free. Class 1 implementations are no longer included in modems.

Class 2

MNP Class 2 uses asynchronous byte-oriented full-duplex data exchange (i.e., data goes in both directions at once). All microprocessor-based modems are capable of supporting MNP Class 2 performance.

Class 3

This class uses synchronous bit-oriented full-duplex data exchange, eliminating the overhead of start and stop bits used in byte-oriented asynchronous communications. The user still sends data asynchronously to the modem while communications between modems is synchronous.

Class 4

This class introduces two new concepts Adaptive Packet Assembly and Data Phase Optimization, both of which further enhance performance. Adaptive Packet Assembly means that the size of the packets in which data is sent between modems is altered according to the quality of the physical link. The higher the line quality, the larger the packets. Larger packets, while more efficient (the ratio of user data to control data is higher), are also more susceptible to errors. Data Phase Optimization means that repetitive control information is removed from the data stream to make packets more efficient. Both techniques, when combined with Class 3, yield a protocol efficiency of about 120 percent (A V.22bis 2400 bps modem will realize approximately a 2900 bps throughput).

Class 5

This class implements MNP basic data compression to realize a net throughput efficiency of 200 percent on average. (A 2400 bps modem will realize 4800 bps). Class 5 uses a real-time adaptive algorithm to compress data. The real-time aspects of the algorithm allow the data compression to operate on interactive terminal data as well as file transfer data. The adaptive nature of the algorithm means data compression is always optimized for the user's data. The compression algorithm continuously analyzes the user data and adjusts the compression parameters to maximize data throughput.

Class 6

This class implements Universal Link Negotiation and Statistical Duplexing. The first feature allows a single modem to operate at a full range of speeds between 300 and 9600 bps, depending on the maximum speed of the modem on the other end of the link. Modems begin operation at a common slower speed and negotiate the use of an alternative high speed modulation technique. The Microcom AX/9624c modem is an example of a modem that uses Universal Link Negotiation, starting with 2400 bps V.22bis technology and shifting to 9600 bps V.29 fast train technology, if the other modem has that technology too. Statistical Duplexing allows the modem to simulate full-duplex service on the half-duplex V.29 modem connection.

Class 7

This class implements a more efficient data compression method than the one used in Class 5. The difference between the two classes is that Class 5 realizes an average 200 percent speed improvement over a non-MNP modem, versus an average 300 percent improvement for Class 7. Class 7 data compression uses Huffman encoding with a predictive algorithm to represent user data in the shortest possible Huffman codes. In addition to Class 5 and Class 7 data compression, MNP also supports V.42bis data compression. Based on the Lempel-Ziv-Welsh data compression model, V.42bis supports an average 400 percent efficiency improvement.

Class 8

Not defined.

Class 9

This class reduces the amount of time required for the modem to perform two frequently occurring administrative activities: to acknowledge that a message was received and to retransmit information following an error. Message acknowledgment is streamlined by " piggy -backing" the acknowledgment in its own dedicated packet. Retransmission is streamlined by indicating in the error or Negative Acknowledgment Packet (NAK) the order sequence number of each of the failed messages. Rather than sending all the messages over again (even the good ones) from the point of the error, as is usually done with error correcting protocols, only the failed messages are resent .

Class 10

MNP Class 10 consists of Adverse Channel Enhancements that optimize performance in environments with poor or varying line quality, such as cellular telephones, international telephone calls, and rural telephone service. These enhancements fall into four categories:

  1. Multiple aggressive attempts at link setup

  2. Adapting packet size to accommodate varying levels of interference

  3. Negotiating transmission speed shifts to achieve the maximum acceptable line speed

  4. Dynamically shifting to the modem speed most suitable to transmission line conditions

See Error Control Protocols and LZW.


The combination of CPU (Central Processing Unit) and other peripherals (I/O, memory, etc.) that form a basic computer system. See Microprocessor.


The traditional definition: A little world; a miniature universe. A smaller, representative unity having analogies to a larger unity. A Jimmy Stewart movie, Magic Town, features "Grandview," a small town in the Midwest that is a perfect statistical microcosm of the United States, a place where the citizens ' opinions match perfectly with Gallup polls of the entire nation. George Gilder defines it as the domains of technology unleashed by discovery of the inner structure of matter in quantum theory early in the 20th century. The epitome of the microcosm is the microchip.

MicroElectroMechanical System

MEMS. Semiconductor chips that have a top layer of mechanical devices, such as mirrors or fluid sensors. MEMS devices are used to make pressure, temperature, chemical and vibration sensors, light reflectors, and switches as well as accelerometers for air bags, vehicle control, pace makers and games . They are also used in the construction of microactuators for data storage and read/write heads, and are a key component for photonic switches, which can be used in cross-connect, add/drop multiplexer, dispersion compensation, and gain-equalization applications. MEMS also are used in optical switching systems, which offer clear advantages in purely optical systems such as DWDM (Dense Wavelength Division Multiplexing) combined with EDFA (Erbium-Doped Fiber Amplification) and Raman amplification. There are two types of MEMS switches: mechanical and microfluidic. Mechanical MEMS switches involve vast arrays (as many as hundreds of thousands) of micromachined mirrors on a silicon chip. Control signals (electromagnetic or thermal) adjust the mirrors to switch optical signals between incoming ports and outgoing ports associated with optical fibers. Microfluidic MEMS switches involve the movement of fluids contained in tiny channels etched into the silicon chips in the form of an intersecting grid configuration. In default mode, the fluids allow the light signal to pass through. If the signal is to be switched, tiny bubbles are injected into and removed from the fluid hundreds of times per second, thereby reflecting the signal to the proper output port.


Microdisplays are a sector of the flat panel display industry used in small optically-viewed devices such as video headsets, camcorders, viewfinders , and other portable devices. Microdisplays are typically of such high resolution that they are only practically viewed with optics (a fancy word for a specially-designed magnifying glass). Although the displays are typically sized less than two inches, many can provide a magnified viewing area similar to that of a full size computer screen. For example, when viewed through a lens, a high-resolution 3/4-inch diagonal display can be made comparable to viewing a 21-inch diagonal computer screen or a large TV screen.


A rectangular sheet of transparent film that contains multiple rows of greatly reduced page images of report, catalogs, rate books, etc.


A small roll of photographic film which can hold several thousand document pages which, when projected onto a screen, produces a legible copy of the item or form photographed.


The latest generation of floppy disks at 3 1/2 inches diameter, invented by Sony. The microfloppy is used in the Apple Macintosh and most MS-DOS laptop computers. Used in an MS-DOS machine, a 3 1/2 inch microfloppy diskette will currently format to carry 1.44 million bytes of data ” equivalent to about 500 pages of double spaced text.

Microfluidic Optical Fibers

The blazing-fast Internet access of the future ” imagine downloading movies in seconds ” might just depend on a little plumbing in the network. In the February 2004 issue of MIT Technology Review, the editors wrote, "Tiny droplets of fluid inside fiber- optic channels could improve the flow of data-carrying photons , speeding transmission and improving reliability. Realizing this radical idea is the goal of University of Illinois physicist John Rogers, whose prototype devices, called microfluidic optical fibers, may be the key to superfast delivery of everything from e-mail to Web-based computer programs, once "bandwidth" again becomes the mantra. Rogers began exploring fluid-filled fibers more than two years ago as a researcher at Lucent Technologies' Bell Labs. While the optical fibers that carry today's phone and data transmissions consist of glass tubing that is flexible but solid, Rogers employs fibers bored through with microscopic channels, ranging from one to 300 micrometers in diameter, depending on their use. While Rogers didn't invent the fibers, he and his team showed that pumping tiny amounts of various fluids into them - and then controlling the expansion, contraction, and movement of these liquid "plugs" - causes the optical properties of the fibers to change. Structures such as tiny heating coils printed directly on the fiber precisely control the size, shape, and position of the plugs. Modifying the plugs' properties enables them to perform critical functions, such as correcting error- causing distortions and directing data flows more efficiently , thus boosting bandwidth far more cheaply than is possible today." See also Microfluidics.


Microfluidics is the scaling down of laboratory fluid tests to miniature sizes. Lab experiments can be performed by manipulating tiny amounts of chemicals and biological samples on chips containing tiny tubes and vessels. Amounts of fluids in quantities as small as microliters, nanoliters or even picoliters can be handled. This technique saves the use of large amounts of expensive chemicals and precious samples, and may help speed up new discoveries by enabling scientists to automate thousands of experiment a day with great accuracy. Microfluidics hardware requires construction and design that differs from conventional hardware, as it is not generally possible to scale conventional devices down to miniature size and expect them to work. When the dimensions of a device or system reach a certain size as the scale becomes smaller, the particles of fluid, or particles suspended in the fluid, become comparable in size with the apparatus itself. This dramatically alters system behavior, as capillary action changes the way in which fluids pass through microscale-diameter tubes, as compared with macroscale channels. See also Microfluidic Optical Fibers.


Microform means Microfiche and Microfilm.


Conversion of information into or from microfilm or microfiche.


One thousandth of a millimeter. Or one millionth of a meter. A unit of measurement corresponding to 1/25,000 of an inch or 40 millionths of an inch.. A micron can be used to specify the core diameter of fiber-optic network cabling. This diameter should match your hardware vendor's requirements; but if you install fiber before you buy the equipment, specify the 62.5-micron size.


An on-line payment of a dime or less. Touted as the key catalyst for Internet commerce, micropayments were conceived as a means of generating revenues which would be significant for vendors, in the aggregate, while being so trivial to the individual users that they would not hesitate make micropayments freely . While still rhetorical , micropayments were to apply to such services as custom newsfeeds, processing applets and data queries.


A transducer that changes the air pressure of sound waves into an electrical signal that can be recorded, amplified and/or transmitted to another location.


An electronic circuit, usually on a single chip, which performs arithmetic, logic and control operations, with the assistance of internal memory. The microprocessor is the fabled "computer on a chip," the " brains " behind all desktop personal computers. Typically, the microprocessor contains read only memory ” ROM ” (permanently stored instructions), read and write memory ” RAM, and a control decoder for breaking down the instructions stored in ROM into detailed steps for action by the arithmetic logic unit ” ALU ” which actually carries out the numerical calculations. There's also a clock circuitry which connects the chip to an exterior quartz crystal whose vibrations coordinate the chip's operations, keeping everything in step. And finally, the input/output section directs communications with devices on the outside of the chip, such as the keyboard, the screen and the various disk drives .

The Fortune Magazine issue of May 6, 1991 contained a very good explanation of chips and microprocessors (usually used interchangeably). Here is the article, slightly condensed:

Chips today can store and retrieve data, perform a simple mathematical calculation, or compare two numbers or words in a few billionths of a second. And they can carry out tens of thousands of such tasks in the blink of an eye. Today's chips contain millions of transistors , capacitors, diodes, and other electronic components, all connected by metallic threads a fraction of the diameter of a human hair. A single chip the size of a fingernail can store dozens of pages of text or combine circuits that can perform scores of tasks simultaneously .

Most chips fall into one of two categories - memory chips and logic chips. Memory chips have the easier job: They merely store information that will be manipulated by the logic chips, the ones with the smarts. Today's biggest-selling memory chip (mid-1991) is the one-megabit dynamic random access memory, or DRAM. Each DRAM is a slice of silicon embedded with a lattice of 1,000 vertical and 1,000 horizontal aluminum wires that circumscribe one million data cells. The densest DRAM designed so far has 64 million cells .

Think of those wires as streets and those cells as blocks. Each block contains a transistor that can be turned on or off ” to signify 1 or 0 ” and that can be identified by it's unique "address" in the wire grid, much like a house in a suburban subdivision. Each digit, letter, or punctuation mark is represented by 1's or 0's stored in eight-cell strings. (See ASCII.) The word "chip" takes up 32 cells in a memory chip. Most PCs sold today have at least eight one-megabit DRAMs.

It's the job of the logic chips to turn those transistors in the DRAMs on or off, and to retrieve and manipulate that information once it's stored. The most important and complex logic chips are microprocessors like Intel's 80386DX, the brains of the more powerful IBM- compatible PCs sold today. If the structure of a memory chip is a suburban subdivision, the layout of a microprocessor is more like an entire metropolitan area, with distinct neighborhoods devoted to different activities. A typical microprocessor contains among other things:

  • A timing system that synchronizes the flow of information to and from memory and throughout the rest of the chip.

  • An address directory that keeps track of where data and program instructions are stored in the DRAMs.

  • An arithmetic logic unit with all the circuits needed to crunch numbers.

  • On-board instructions that control the sequence of microprocessor operations. Other logic chips in a computer take their cues from the microprocessor millions of times each second to draw images on the screen, to feed instructions from a spreadsheet program, say, out of the disk drives into DRAMs, or to dispatch data to a modem or a printer. Perhaps most amazing of all, memory and logic chips can accomplish all this with just a trickle of electricity - far less than it takes to light a flashlight bulb.

Ted Hoff at Intel invented the microprocessor in 1971. See also 1971 in the beginning of this dictionary.

Microprocessor Controls

A control system that uses computer logic to operate and monitor an air conditioning system. Microprocessor controls are commonly used on modem precision air conditioning systems to maintain precise control of temperature and humidity and to monitor the unit's operation.


Unlike traditional satellites , which can weigh tons, microsatellites are the size of a suitcase and weigh about 220 lbs. Since it costs "a bar of gold to launch a can of Coke," according to the New York Times, lightweight microsatellites will be much cheaper to launch than their obese precursors. The U.S. military's goal is to send microsatellites into space in flocks. In this cluster, they would be reprogrammable, able to switch to new tasks when the Pentagon required it.


One millionth of a second. A microsecond is ten to the minus six. One microsecond ” a millionth of a second ” is the duration of the light from a camera's electronic flash. Light that short freezes motion, making a pitched ball or a bullet appear stationary. See Atto, Nanosecond, Femto and Pico.


The process of configuring Ethernet and other LANs with a single workstation per segment. The objective is to remove contention from Ethernet segments. With each segment having access to a full 10 Mbps of Ethernet bandwidth, users can do things involving significant bandwidth, such as imaging, video and multimedia.


Division of a network into smaller segments, usually with the intention of increasing aggregate bandwidth to devices.


The time between two consecutive busy/idle flags (60 bits, or 3.125 milliseconds at 19.2 kbps). It is used in CDPD only. A cellular radio term.


Founded in 1975 by Bill Gates and Paul Allen as Micro-soft (now called Microsoft) it is (or was at the time of writing this edition of this dictionary) one of the largest software companies in the world. See the next few definitions.

Microsoft At Work

A new architecture announced by Microsoft on June 9, 1993 and then put into retirement a couple of years later. Many of its features and ideas surfaced in Windows 95. It consisted of a set of software building blocks that will sit in both office machines and PC products, including:

  • Desktop and network-connected printers.

  • Digital monochrome and color copiers.

  • Telephones and voice messaging systems.

  • Fax machines and PC fax products.

  • Handheld systems.

  • Hybrid combinations of the above.

According to Microsoft, the Microsoft At Work architecture focuses on creating digital connections between machines (i.e. the ones above) to allow information to flow freely throughout the workplace. The Microsoft At Work software architecture consists of several technology components that serve as building blocks to enable these connections. Only one of the components, desktop software, will reside on PCs. The rest will be incorporated into other types of office devices (the ones above), making these products easier to use, compatible with one another and compatible with Microsoft Windows-based PCs. The components, according to Microsoft, are:

  • Microsoft At Work operating system. A real-time, preemptive, multi tasking operating system that is designed to specifically address the requirements of the office automation and communication industries. The new operating system supports Windows compatible application programming interfaces (APIs) where appropriate for the device.

  • Microsoft At Work communications. Will provide the connectivity between Microsoft At Work-based devices and PCs. It will support the secure transmission of original digital documents, and it is compatible with the Windows Messaging API and the Windows Telephony API of the Windows Open Services Architecture (WOSA).

  • Microsoft At Work rendering. Will make the transmission of digital documents, with formatting and fonts intact, very fast and, consequently, cost-effective ; will ensure that a document sent to any of these devices will produce high-quality output, referred to as "What You Print Is What You Fax Is What You Copy Is What You See."

  • Microsoft At Work graphical user interface. Will make all devices very easy to use and will make sophisticated features accessible; will provide useful feedback to users. Leveraging Microsoft's experience in the Windows user interface, Microsoft At Work-based products will use very simple graphical user interfaces designed for people who are not computer users.

  • Microsoft At Work desktop software for Windows-based PCs. Will provide Windows- based PC applications the ability to control, access and exchange information with any product based on Microsoft At Work. Desktop software is the one piece of the Microsoft At Work architecture that will reside on PCs. See also Fax At Work, Voice Server, Windows, Windows CE, Windows 95, Windows Telephony and WOSA.

Microsoft Exchange

A family of products that offers enterprise computing and information sharing. According to the Windows 95 Resource Kit, Windows 95 includes the Microsoft Exchange client, an advanced messaging application that retrieves messages into one inbox from many kinds of messaging service providers, including Microsoft Mail, The Microsoft Network and Microsoft Fax. Its integration with Microsoft Fax software allows you to send rich-text documents as faxes or mail messages. With Microsoft Exchange client, you can do the following:

  • Send or receive electronic mail in a Win 95 workgroup.

  • Include files and objects created in other applications as part of messages.

  • Use multiple fonts, font sizes and colors, and text alignments in messages.

  • Create a Personal Address Book or use address books from multiple service providers.

  • Create folders for storing related messages, files, and other items.

  • Organize and sort messages in a variety of ways.

  • Send and receive messages to and from the following service providers Microsoft Mail, the Microsoft Network (online service), Microsoft Fax and other messaging services that use MAPI service providers.

Microsoft Fax

I plucked the following explanation from the Windows 95 Resource Development Kit: With Microsoft Fax, users with modems can exchange faxes and editable files as easily as printing a document or sending an electronic mail message. Microsoft Fax is compatible with the millions of traditional Group 3 fax machines worldwide, yet it provides advanced security and binary file transfer (BFT) features that make sharing information by means of a fax easier and more powerful. To use Microsoft Fax, you must install Microsoft Exchange. Microsoft Fax has been integrated into Microsoft Exchange as a Messaging Application Programming Interface (MAPI) service provider. All faxes sent to Microsoft Fax are received in the Microsoft Exchange universal inbox. You can send a fax by composing a Microsoft Exchange message, or by using the Send option on the File menu of a MAPI-compatible application (such as Microsoft Excel or Microsoft Word).

Microsoft Solution Provider

This is Microsoft's definition: Microsoft Solution Providers are independent organizations that have teamed with Microsoft to use technology to solve business problems for companies of all sizes and industries. SPs use the Microsoft Solutions Platform of products as building blocks and offer various value- added services, such as integration, consulting, software customization, developing turnkey applications and technical training and support. All Solution Providers have at least one Microsoft Certified Professional on staff who has demonstrated expertise in developing, implementing, and supporting Microsoft solutions.

Microsoft Speech API

The Microsoft Speech API is a set of applications programming interfaces (APIs) which allow applications to incorporate speech recognition and text-to-speech in their Win32 applications (for Windows 95 or Windows NT). All of the APIs are accessed through the OLE Component Object Model and derive benefits from this object- oriented approach. Like other Windows Open Services Architecture (WOSA) services (e.g. TAPI), the Microsoft Speech API provides a set of standard APIs which allow Windows developers to add speech capabilities to their applications without being tied directly to a specific speech engine technology.

Here are some specific areas where speech recognition and text-to-speech can improve a user-interface in any application, and a few uses to avoid. This list of pros and cons is courtesy Mike Rozak, Microsoft software design engineer.

What speech recognition is good for...

  • Fast access to complex features. Some applications have features that are frequently used but which are difficult to present/control with a GUI. Often times the features can be more easily accessed by speech recognition.

  • Magic keystrokes. Many applications have overloaded the keyboard with not only text entry features, but also commands. Some applications have so many keyboard accelerators that they distinguish between ctrl-f2, shift-f2, alt-f2, etc. These are difficult for the end-user to memorize. Using voice commands to replace these makes life easier for the user because voice commands are easier to memorize.

  • Macros. Macros are related to magic keystrokes. Many applications allow users to create macros that speed up frequently-done or difficult tasks. To activate these macros, users often have to invent and memorize a magic keystroke. The keystroke can be replaced with speech, whose commands are easier to memorize and are less likely to cause an accelerator conflict.

  • Global commands. At times, an application wants to have an input hook that is always active, even when the application doesn't have keyboard focus. If the application uses a keyboard hook then it's likely that the chosen key will already be used by another application, causing conflicts. Because there are so many different possible sentences, an application can provide a global command that is always active and not worry about conflict. Example: A PC-based phone can use global commands for "Call <name>", so that a user can make a phone call even when the phone isn't the active application.

  • Anthropomorphize the computer. If you want the user to perceive the computer as a person, then the application should use speech ( synthesized or recorded) to talk to the user information, and speech recognition to get information from the user. The computer can listen for commands, or answers to questions, using speech recognition.

  • Interaction with characters. Applications that have characters, especially adventure games, have a lot to gain from speech. Simulating characters is a specialized anthropomorphizing of the system.

  • Form entry - Applications can use speech recognition for form entry, both for selecting elements from a list, and entering numbers. Because speech can have so many commands active at once, it can be listening for all of the possible values for all of the fields at once, and infer which field the user wanted filled in. Example: If a user spoke, "Male, sixteen, one hundred and fifty pounds ," the application could correctly identify which field was being referred to by "male", "sixteen", and "one hundred and fifty pounds ", set the focus to the proper field for each command, and place in the proper data. The user doesn't have to worry about tabbing around.

  • Sit back and relax. If you watch users sitting in front of a computer, you'll notice that whenever they type or use the mouse they hunch forward. If you want the user to relax and sit back while using your application, you should provide a speech recognition interface. Example: A consumer title might want to use speech recognition in order to make the computer seem less work-oriented because the user can sit back in his chair without touching the keyboard and mouse.

  • Dictation for poor typists. Current dictation technology (which requires that users leave pauses between words) is good for people who cannot type or who are poor typists. The only reason not to include dictation is that dictation systems require about 8 megabytes of extra RAM.

  • Access over the telephone. With the arrival of voice-modems in more and more PCs, applications will start providing "phone-based" UIs. Speech recognition is a much better interface than maneuvering through menus with touch-tones, especially since most Europeans don't have touch-tone phones. Example: A user will call up his computer and ask to speak to his PIM application, which then allows him to look up his schedule, address book, etc., all over the phone. The user can merely say, "Give me the phone number for John Smith

  • Accessibility. Some people cannot use the keyboard or mouse effectively. The most common disability is carpel tunnel syndrome or equivalent. Adding speech recognition enables them to use the application.

  • Mouse overloaded. Some applications (especially CAD systems) drag, drop, and select objects with the mouse. If the user wants to do any more complex actions, he either has to memorize a magic keystroke (which may not have the information bandwidth), or move the mouse to a menu/toolbar. Instead, the user could just speak, "Rotate this sixty two degrees."

  • No keyboard/mouse available. Sometimes a keyboard or mouse is not available. This happens a lot in kiosk situations, where the kiosk has the keyboard and mouse hidden so that users don't feel intimidated, won't break the devices, and won't steal the devices. In order to get input from the users, current systems use a touch- screen. Why not use speech recognition?

  • Hands busy. If a user's hands are busy, then speech is useful. Example: Some dentists' offices use speech recognition to enter charts about the patient's teeth because their hands are busy probing around the patient's mouth.

  • Multiple people in front of machine. Speech recognition is good for applications that have several people sitting in front of the same computer, each participating in the application. Normally, an application which is to be used by several users would require that they pass the mouse and/or keyboard around. Since speech recognition is effective up to several feet, users would just have to sit around the computer and talk to it.

Where not to use speech recognition...

  • Selecting from a large list of words. Most recognition systems break down when more than 100 words/commands are active, so keep lists below this number. For example, allowing the user to address electronic mail to any of 10,000 employees will not work well; instead, it would be better to allow any name from the 100 (or 75, or 50) employees to whom the user frequently sends mail.

  • Spelling. Asking a user to spell a word does not work well because many letters such as "m" and "n" sound the same. Instead, it would be better to ask the user to type the word or offer a list of possibilities. Spelling with communications code words_"alpha," "bravo," "charlie," and the like_may be appropriate for certain vertical markets but not for general-purpose applications.

  • Entering long sequences of numbers. Most engines will have a very high error rate for long series of digits that are spoken continuously. For phone numbers or other long series, either break the number into groups of four or fewer digits or have the user speak each digit as an isolated word.

  • Pointing device. Do not use speech as a pointing device. Speaking "up" five times in a row is very annoying to the user.

  • Action games. Because of the background noise (music and sound effects) that is typically present, speech recognition does not work well for action games. The speech-recognition engine spends time processing audio from the computer's speakers and may even recognize it as commands. Speech-recognition works for action games only if the user wears a close-talk microphone (for example, a headset). Additionally, by the time that the user finishes saying, "Fire," it's probably too late.

Microsoft SQL Server

A Microsoft retail product that provides distributed database management. Multiple workstations manipulate data stored on a server, where the server coordinates operations and performs resource intensive calculations.

Microsoft TAPI

See TAPI and Windows Telephony.


A term coined by James Gleick in The New York Times Magazine of June 18, 1997 to refer to the language of euphemisms Microsoft Corporation often indulges in. For example, Mr. Gleick referred to Microsoft's seeming unwillingness to use the word "bug" and use words such as "known issue," "intermittent issue", "design side effect," "undocumented behavior," or "technical glitch."


A small electronic ecommerce transaction ” under ten cents . The significance of the term "microtransaction" is that there is a real need for such small transactions on the Internet ” but no one has figured a way to bill economically in such small amounts. Ultimately, someone will. You might need a microtransaction, for example, if you were renting software for small amounts of time.


How to get broadband fiber or caox to the last mile? You can't dig the big trenches we use for long-haul. Those trenches are too expensive and easily cost $100 a foot . A new digging technique known as micro trenching to the rescue. Micro trenching involves the creation of a shallow trench in the sidewalk or street asphalt, which is typically one-quarter of an inch wide and two to six inches deep. The layer of road base is not even touched. Using this method, a crew can lay as much as a thousand feet of fiber per day. Moreover the cost is typically one-fifth to a half of what normal trenching costs. Micro trenching also eliminates red tape and saves time. Surveying and permitting may take 30 days for a micro trenching job, as opposed to 60 or more days for a traditional trenching project. The difference is even more glaring when comparing the trenching work itself. A build may take as little as two days for micro trenching, but 30 or more days for conventional trenching work. From planning to completion, the build time frame for micro trenching may be 50 to 55 days, whereas the traditional approach can take 160 days, or more. Time is money. Much of this definition comes from Bill Morrow is vice chairman and CEO of Grande Communications, a Texas telecom company.


Electromagnetic waves in the radio frequency spectrum above 890 Megahertz (million cycles per second) and below 20 Gigahertz (billion cycles per second). (Some people say microwave refers to frequencies between 1 GHz and 30 GHz.) Microwave is a common form of transmitting telephone, facsimile , video and data conversations used by common carriers as well as by private networks. Microwave signals only travel in straight lines. In terrestrial microwave systems, they're typically good for 30 miles, at which point you need another repeater tower. Microwave is the frequency for communicating to and from satellites.

Microwave Absorber

A tuned device used for blocking and preventing or reducing the re-emission or reflection of microwave frequency energy.

Microwave Band

Loosely defined as those frequencies from about 1 gigahertz upward, Services that use microwave frequencies for point-to-point and point-to-multipoint communications include common carrier, cable TV operators broadcasters, and private operational fixed users.

Microwave Diffraction

The tendency of microwave radiation to "bend" around objects.

Microwave Ducting

Under certain conditions the earth and the upper atmosphere can sometimes behave as a wave guide with respect to microwave signals carrying them long distances.

Microwave Multi-Point Distribution System

MMDS. Microwave Multi-point Distribution System. A means of distributing cable television signals, through microwave, from a single transmission point to multiple receiving points. Often used as an alternative to cable-based cable TV. According to an April, 1995 press release from Pacific Telesis, which was starting an MMDS service, "in digital form, it will provide more than 100 channels to a radius of approximately 40 miles from the transmitter. The MMDS transmitter delivers video to homes that are in its 'line of sight.' MMDS transmissions are limited by the terrain and foliage of a given market. The microwave signal is received by an antenna on the subscriber's home, then sent down coaxial cable to a box atop the customer's TV set. The box decodes and decompresses the digital signal."

Microwave Oven

The following "urban legend" seems to be quite prevalent on the internet: "The microwave oven was invented after a researcher walked by a radar tube and a chocolate bar melted in his pocket." Actually, there is a kernel of truth in this, but it is, alas, inaccurate. The device was actually invented after researchers working on radar at Bell Labs noticed that a chocolate bar that had been left near a magnetron melted after a few hours of exposure. If a researcher had a chocolate bar melt in his pocket as he walked by radar equipment, he would most probably would have melted with it.

Microwave Pill

In space weaponry, one idea is to place a microwave gun on board a microsatellite. Have the microsatellite siddle alongside your enemy's satellite, then emit a pulse of microwaves and fry your enemy's electronics permanently. This application, in U.S. military parlance, is called a "high-power microwave pill."

Microwave Pulse Generator

MPG. A device that generates pulses at microwave frequencies.

Microwave Reflection

The tendency of microwave radiation to bounce off objects and behave according to the physical principles of light.

Microwave Tags

RFID radio frequency tags that operate at 5.8 GHz. They have very high transfer rates and can be read from as far as 30 feet away, but they use a lot of power and are expensive.


An ATM term. Message Identifier. The message identifier is used to associate ATM cells that carry segments from the same higher layer packet.

Mid Span

See 802.3af.

Mid-air Passenger Exchange

Grim air traffic controller speak for a head-on collision. Midair passenger exchanges are quickly followed by "aluminum rain." Definition from Wired Magazine.


A phone service that runs from a pole to a hook attached to a cable strand before it reaches the building.

Mid-span Device

See 802.3af.

Mid-span Meet

Sonet's ability to mix the terminal, multiplexing and cross-connect equipment from different vendors. A major accomplishment for standardization. Wish more telecom systems could meet mid-span. Sadly, most can't.


A broadband cable system in which the cable bandwidth is divided between transmit and receive functions. A cable television system in which the guard band (or split) between the upstream and downstream signals is at 114-150 MHz. Defined in IEEE 802.7. Compare to the definitions of Sub-Split and High-Split.


Microsoft's word for telecom speeds that are faster than phone lines but slower than broadband networks. ISDN BRI is midband.

Middle Mile

The connection between an ISP and the Internet Backbone. The middle mile consists of one or more carrier networks that move traffic from the access ISP to the "final" ISP. This is where path diversity takes place; indeed traffic typically takes two different paths through this middle mile - traffic flowing from the client to the content provider takes one route, while traffic from the content provider back to the client takes a different path. This is due to the carrier's policies (e.g. hot-potato routing) or to the decisions the Border Gateway Protocol (BGP) makes from each perspective. The middle mile is the section of the link where path diversity is possible.


Middleware is software which sits between layers of software to make the layers below and on the side work with each other. Essentially , middleware serves as a translation mechanism, gluing together application software across a network, and on a transparent basis. On that broad definition, middleware could be almost any software in a layered software stack. Let's consider several examples: In computer telephony, middle- ware tends to be software that sits right above that part of the operating system dealing with telephony ” TSAPI in NetWare or TAPI in Windows ” but below the computer telephony application above it which the user sees on their desktop. Database middleware supports one-way access from clients to a server-based database. Messaging middleware is similar to an e-mail system, allowing systems to exchange data.


Communications software that acts as a universal translator between diverse radio frequencies and protocols. The software physically resides on a remote client and on a communications server located between the client and the applications server.


Musical Instrument Digital Interface, a standard for connecting musical instruments, synthesizers and computers. The MIDI standard provides a way to translate music into computer data, and vice versa. A file with a MIDI extension means that it's a file containing music. In contrast, a file with the extension WAV typically means it's a sound file, which means it may contain a voice recording.


Mobile Information Device Profile. Set of Java APIs that is generally implemented on the Connected Limited Device Configuration (CLDC). It provides a basic J2ME application runtime environment targeted at mobile information devices, such as mobile phones and two-way pagers . The MIDP specification addresses issues such as user interface, persistent storage, networking, and application model.

Midrange System

Medium-scale computer that functions as a workstation or as a multiuser system handling several hundred terminals.

Midspan Repeater

A device that amplifies the signal coming or going to the central office. This device is necessary for ISDN service if you are outside the 18,000 feet distance requirement from the central office.


A broadband cable system in which the cable bandwidth is divided between transmit and receive frequencies. The bandwidth used to send toward the head-end (reverse direction) is about 5 MHz to 116 Mhz, and the bandwidth used to send away from the head-end (forward direction) is about 168 MHz to 400 Mhz. The guard band between the forward and reverse directions (100 MHz to 160 MHz) provides isolation from interference. Requires a frequency translator.


  1. Management Information File. MIF is a file format for DMI that describes components within a PC. See WFM.

  2. Minimum Internetworking Functionality. A general principle within the ISO that calls for minimum local area network station complexity when interconnecting with resources outside the local area network.


An AT&T marketing strategy designed to encourage all phone equipment month-to-month renters into long-term contracts for AT&T's "flagship products", i.e., System 75, 85 and Definity PBXs.


See Media Independent Interface.




1/1000 of an inch.


See Airline Mileage.

Mileage Range Indicator

A code that denotes the mileage range being billed.

Mileage Sensitive rates

Mileage sensitive rates (also called "banded rates") are rates that increase with physical distance. For example, if you live in New York City, a call to (or from) New Jersey will cost less than a call to (or from) California. Things are changing, however. Most calls now in the United States are distance insensitive, and are only time sensitive. They charge by time, not for how far you call.

Military-Industrial Complex

In his farewell remarks as president in 1961, Dwight Eisenhower famously warned about a "military-industrial complex" made up of the "conjunction of an immense military establishment and a large arms industry."

Millennium Bug

Y2K, Year 2000. See Y2K.


One thousandth. Millisecond equals one thousandth of a second.

Millimeter Wireless

Operating at microwave frequencies with a separation of millimeters between peaks and troughs of the radio wave, millimeter wireless includes LMDS (Local Multipoint Distribution Services) and MMDS (Multichannel Multipoint Distribution Services). See also LMDS and MMDS.


Millisecond equals one thousand of a second.

Millions of Floating Instructions Per Second

A measure of computing power. Processors are assigned a value in terms of their ability to perform complex mathematical operations (multiplications, division, addition, and subtraction) with "floating point" (non-integer) numbers.

Millions of Instructions Per Second

A measure of computing power measured in terms of the number of instructions in can execute in a second. Its merit is highly dependent, of course, on how powerful its instructions actually are. That is, two computers with the same MIPS ratings might have significantly different computing power if one of the computes has instructions that can accomplish twice as much per instruction as the other on the average.


One thousandth of a WATT. Used as a reference point for signal levels at a given point in a circuit.

Milliwatt (102 Type) Test Line

An arrangement in an end office that provides a 2004 Hz tone at 0 dBm0 for one-way transmission measurements towards the customer's premises from the local exchange carrier's end office.


MILitary NETwork. Along with DARPANET, MILNET was created in 1983 as successor to the ARPANET. One of the DDN networks that make up the Internet; devoted to non- classified U.S. military communications. SEE ARPANET.


Military Specification. Milspecs are very demanding.


Metal-Insulator-Metal. A display technology which uses active matrix technology that uses diodes behind each pixel to produce images. It is an improvement on passive displays but a step behind TFT (Thin Film Transistor) technology. See also LCD.


Multiple Instruction Multiple Data is a type of parallel processing computer, which includes dozens of processors. Each processor can run different parts of the same program and execute those instructions on different data. This makes it more flexible, though more expensive than a computer running SIMD ” single instruction multiple data.


Multipurpose Internet Mail Extensions. Developed and adopted by the Internet Engineering Task Force (IETF) in RFC 1521, MIME is the standard format for including non- text information in Internet mail, thereby supporting the transmission of mixed-media messages across TCP/IP networks. The MIME protocol, which is actually an extension to SMTP, covers binary, audio and video data. MIME also is the standard for transmitting foreign language text (e.g., Russian or Chinese) which cannot be represented in plain ASCII code. Here's an explanation: When sending files which aren't plain US-ASCII across a network ” dial-up, leased or the Internet ” you basically have two options. First, you can attach them as a binary file (i.e., non-ASCII file). Or second, you can encode them into ASCII characters and send the file as part of your message. The first method is preferable. But you can typically only send binary files from one account to another on the same network, or between two networks that have agreed between themselves to a method of transferring files. That's a rarity. And it certainly doesn't work in and around the Internet. Therefore, MIME was created, employing a base64 coding scheme, which involves relatively simple encoding and decoding algorithms. See also base64, BinHex, Multipurpose Internet Mail Extensions and UUencode.


Modified Modular Jack. These are the 6-pin connectors used to connect serial terminal lines to terminal devices. MIMJ jacks can be distinguished from the familiar RJ11 jacks by having a side-looking tab, rather than a center-mounted one.


Multiple Input and Multiple Output. A wireless technique whereby multiple input and output radio channels are used to improve transmission quality. MIMO systems are smart antenna systems involving intelligence on both sides of the transmission, i.e., the transmit side and the receive side. The technique involves Space Division Multiplexing (SDM), with arrays of multiple spacially separated transmit and receive antennas.


Mobile Identification Number. A 24-bit number corresponding to the actual 7-digit telephone number assigned by the cellular carrier exclusively to your phone, used for both billing and for receiving calls. The MIN is meant to be changeable , as the ownership of the device may change hands, the owner may change telephone numbers, or the owner may change cities. The MIN is paired with the Electronic Serial Number (ESN). Theoretically, both numbers are verified , and in combination, every time a call is placed in order to verify the legitimacy of the device and the call. See MIN2 and ESN.

MIN Mark

Can be 0 or 1. Your home cellular station sends extended address data upon origination and page response. See MIN1.


The area code of your cellular phone number.


See COW.


A floppy disk that is 3 1/2 inches in diameter. Also called a microfloppy. See Microfloppy.


Mini-Manufacturing Automation Protocol. A version of MAP consisting of only physical, link and application layers intended for lower-cost process-control networks. With mini-MAP, a device with a token can request a response from an addressed device. Unlike a standard MAP protocol, the addressed Mini-MAP device need not wait for the token to respond.


See MTU and POP.


A computer smaller than a mainframe, but bigger than a PC. Minicomputer is a loose term for describing any general-purpose digital computer in a lowto-moderate price range. Minicomputers used to be primarily used for the processing of a single application or the processing of a number of small applications. For example, in a distributed processing network, a minicomputer could perform a specific operation and send the volume processing through communication lines to a large mainframe. Today the tasks that were performed by minicomputers are now largely performed by industrial grade PCs working singly or together on a local area network.

Minimal Regulation

Regulated local telephone company under limited state regulation has the ability to file price lists for services and those price lists are usually effective on 10-days' notice to local state commission and customers. This means there are no extensive hearings.

Minimize Button

The minimize button is the down-arrow button at the immediate right of a title bar in Windows software. Clicking the minimize button will shrink a window to its icon.

Minimum Cell Rate

MCR. ATM performance parameter that specifies the minimum rate for cell transmission that a network must guarantee to a user on a given virtual circuit. Also, a field in an RM cell specifying the smallest value to which the ER field can be set.

Minimum Internetworking Functionality

MIF. A general principle within the ISO that calls for minimum local network station complexity when interconnecting with resources outside the local network.

Minimum Point of Entry

MPOE. The closest practical point to where the carrier facilities cross the property line or the closest practical point to where the carrier cabling enters a multi-unit building or buildings. The MPOE typically is in the form of a physical demarcation point (demarc), although it may simply be in form of a tag hung on the entrance cable to identify a point of logical demarcation . In either event, the MPOE establishes the point at which the carrier's responsibility ends, and that of the end user organization or building owner begins. The MPOE commonly is a point on the entrance cable which is 12 inches from the inside wall. In a campus environment, with multiple entrance cables to multiple buildings, the MPOE is the most logical point of demarcation, in the carrier's opinion. See also Demarc.

Minimum Point of Presence

See Minimum Point of Entry.


In Middle English the word "minister" meant "lowly person." It was originally adopted as a term of humility for men of the church .


French name for videotex. See Videotex.

MIP Mapping

A texturing technique used for 3D animation in games and in CAD imaging. When scenery contains acutely angled polygons that disappear into the distance, MIP mapping mixes low and high resolution versions of the same texture to reduce the jagged effect.


Millions of Instructions Per Second. A measure of computer speed that refers to the average number of machine language instructions performed by the CPU in one second. A typical Intel 80386-based PC is a 3 to 5 MIPS machine, whereas an IBM System 370 mainframe typically delivers between 5 and 40 MIPS. MIPS measures raw CPU performance, but not overall system performance.


Maximum Information Rate: See also PCR.


A term used to reference Internet FTP sites that copy files from other archives every day or so. By accessing a mirror site close to your location you reduce transmission over the Internet.

Mirror Image

Your main web site is in California. You have a server in New York, which contains exactly what's on your site in California. Your New York site is thus the mirror image of your California site. The reason you have a second site is so your east coast customers can connect to your New York site faster and more efficiently (i.e. less data loss) than connecting to your California site.

Mirror Server

Imagine you're a big international software company with branches in every country and in every town in the entire universe. You have zillions of users. Every day your users need to download software from you ” fixes, upgrades, etc. If you have only one server (big computer to serve multiple users), that server will bog down in heavy traffic. Also, all your customers overseas will receive their software very very slowly because they're farther away. So the solution is to install a bunch of "mirror servers" all around the world. Each server would be a mirror image of the main one ” the one at your headquarters. That means its content and structure would be identical. The only difference is that servers all around the world would be closer to the users. And when the users come first on-line to your main server and find software they need, they would then be given the choice of having their material downloaded to them from a server that's closer to them. Go to They often allow you to download some new software. As you are about to download, they ask you which server in which country you'd like.

Mirror Set

A fully redundant or shadow copy of data. Mirror sets provide an identical twin for a selected disk; all data written to the primary disk is also written to the shadow or mirror disk. The user can then have instant access to another disk with a redundant copy of the information on the failed disk. Mirror sets provide fault tolerance. See also Fault Tolerance.

Mirror Site

A duplicate Web site. A mirror site contains the same information as the original Web site and reduces traffic on that site by providing a local or regional alternative.

Mirrored Server Link

MSL. A dedicated, high-speed, point-to-point connection between the primary server and the secondary server. The MSL can either be a coaxial or fiber-optic cable (with maximum distances of 100 feet and 2.5 miles, respectively). See MSL.

Mirrored Web-Page Screen Pop

In computer telephony, the ability for a Web-Enabled Call Center agent to assist callers by "pushing" Web pages to their computer while they are on the phone together. The agent's screen mirrors the caller's screen. The agent can do the clicking for the customer so he or she sees the information they're intended to see.


A fault tolerance method in which a backup data storage device maintains data identical to that on the primary device and can replace the primary if it fails. Mirroring will typically cost you a 50% performance degradation when your write to disk and 0% performance degradation when you are reading. For a full explanation, see Disk Mirroring.


  1. Management Information System. A fancy name for Data Processing. MIS are also the first three letters of the word MISanthrope and MISguided and lots of other MIS words. MIS departments are taking over corporate telecommunications departments which is why there's little love lost between the two.

  2. IBM-speak for Management Initiated Separation. Translation: You're fired .

Miscellaneous Common Carrier

A communications common carrier (typically one using microwave) which is not offering switched service to the public or to companies. A miscellaneous common carrier usually provides video and radio leased line transmission services to TV and radio networks.

Miscellaneous Trunk Restrictions

Denies preselected lines access to preselected trunk groups (e.g., FX or WATS trunks). A call attempt over a restricted group routes to an intercept tone.


Multilevel Information Systems Security Initiative. Developed under the leadership of the NSA (National Security Administration), MISSI is a framework for the development and evolution of interoperable, complementary security products intended to provide flexible, modular security for networked information systems. MISSI encompasses a suite of security technologies developed to support national defense operations across the Defense Information Intrastructure (DII) and the National Information Infrastructure (NII), and with application in secure corporate environments. Included in the MISSI Security Solutions suite are a set of best security practices, as well as endorsement of compliant products which implement elements of the architecture. A fully compliant MISSI architecture controls system access by "level" (e.g., unclassified, sensitive, confidential, secret and top secret) and " compartment " (i.e., topical area of interest). Authentication and encryption are provided courtesy of the Fortezza family of chips developed by Mykotronx Inc. See also Fortezza.

Missile Mail

On June 8, 1959, a postal official heralded a move by the US Post Office as being "of historic significance to the peoples of the entire world." On that date, which will live forever in the arcane annals of the USPS (United States Postal Service), the Navy submarine U.S.S. Barbero fired a guided missile carrying 3,000 letters at the Naval Auxiliary Air Station in Mayport, Florida. The official went on to say that "Before man reaches the moon, mail will be delivered within hours from New York to California, to Britain, to India or Australia by guided missiles." See also Snail Mail.

Mission Critical Operation

An operation that an organization considers key to its success and survival, such as sales, marketing, and customer service. An organization will probably be more willing to invest resources in order to fix a problem or make improvements to a "mission critical" operation than to other operations.

Mission Critical Systems

Systems on which the future success of an organization depends.

MIT Media Laboratory

Founded by Nicholas Negroponte, author of the book "Digital," the MIT Media Lab.


Mitel is a IP telephony PBX and computer telephony component maker. The word Mitel actually stands for MIke and TErry's electric Lawn mower. Here's how it happened . In the early 1970s, Mike Cowpland and Terry Matthews were engineers working in the semi-conductor factory of Northern Telecom in Kanata, Ontario, Canada. They decided they wanted to go out on their own. Their first idea was cordless, electric lawn mowers. Apparently they thought there was a demand for such devices. They formed Mitel and ordered electric lawn mowers from a manufacturer in England. The mowers arrived after the onset of the Canadian winter in November, i.e. too late. No one wanted lawn mowers. So Terry and Mike decided to make telephone systems. That went well. Mitel went public. Most of the company was later sold to British Telecom, who lost their shirt on it and eventually sold it on a fire sale to a venture capital company. Terry moved on and founded the eminently successful Newbridge Networks, which he later sold to Alcatel. Mike got involved with Corel, which he eventually screwed up and ultimately got kicked out of. In early 2001, Terry Matthews bought back the trademark and the telecommunications division of Mitel. He and Don Smith are now running Mitel.


Most people think mitzvah is a Jewish word meaning a good deed done without expecting anything in return. This is not correct, according to my authorities who have studied this (i.e. several learned Rabbis). They tell me that "In modern Hebrew mitzvah follows the traditional standard and is used to mean command in a non-religious sense, too. "Ani metzaveh lach" means "I command you" and may be used when speaking to your dog in obedience school. The traditional term for a good deed without hope of repayment was 'chesed shel emmes' or plain 'Chesed'. Joy was 'simcha'. Mitzvah was never used in the way it is commmonly used today ” as a good deed. See also Bar Mitzvah.


  1. Multinational Internet eXchange.

  2. Multicasting International eXchange.

Mixed Cable

Cables have characteristic impedances which vary according to the cables' physical parameters. When cables of different characteristic impedance are mixed, an impedance imbalance will occur. It is thus bad practice to mix different wire gauges, and twisted or non-twisted pair cables. However, it is accepted practice to combine long runs of twisted pair cable with short lengths of modular patch cords and line cords. Baluns are an exception to this rule.

Mixed Mode

An imprecise term which suggests that one digital bit stream can carry voice, data, facsimile and video signals.

Mixed Mode Night Service

After-hours answering of incoming calls in which Assigned Night Answer (ANA) is specified for some trunks, and Universal Night Answer (UNA) specified for others.

Mixed Signal Processor

MSP. A multi-functional chipset that can do both digital-to-analog (D/A) and analog-to-digital (A/D) signal conversions and processing both analog and digital signals. Therefore and for example, a MSP can serve as a codec, converting analog voice into digital signals for transmission over a digital circuit such as a T-1. It also can serve as a modem, converting digital computer signals into analog format for transmission over an analog circuit. On the terminating end of the circuit, the MSP reverses the processes in order to convert the signal back into its native format.

Mixed Station Dialing

A telephone system feature which allows you to install both rotary and pushbutton phones on your phone system. Most modern PBXs have this feature.


Modular Jack. A jack used for connecting voice cables to a faceplate, as for a telephone. See RJ (Registered Jack).


Multi-Junction Unit.


MultiLine Hunt Group.


Multiple Link Interface Driver. A layer of the Novell Open DataLink Interface specification. The MLID layer controls a specific network interface, and works below the Link Support Layer.


Monthly Leased Lines.


Meridian Link Module. A Northern Telecom term for an Application Module that provides a link to a host processor through the Meridian Link interface.


See Multilevel Precedence Preemption.


Microwave Landing System.


Multiple Low Speed CSU.


Minimum Line Scan Time. The minimum amount of time it takes a transmitting fax machine to scan each of the 1,143 fax lines of a document. The MLST of older machines can be as long as 40 milliseconds (ms), or thousandths of a second. The MLST of newer machines can be 20 ms or fewer.


See Mechanized Loop Test.


Multi Level Transmit - 3 Levels. The ANSI approved modulation scheme used for the transmission of data on an FDDI network over shielded and unshielded copper twisted pair media (see TP-PMD).


Mobility Management. A wireless industry term.


Multimedia Mobile Access Communication. MMAC is a wireless standard used largely in Japan. Like IEEE 802.11a and HiperLAN/2, which are both used in North America and Europe, MMAC uses OFDM (Orthogonal Frequency Division Multiplexing) as the physical layer specification and uses data rates ranging from 6 to 54 Mbps in the 5- GHz band. See OFDM. According to the Multimedia Mobile Access Communication Systems Promotion Council (MMAC-PC), an MMAC is a mobile communication system that can "transmit ultra high speed, high quality Multimedia Information ' anytime and anywhere ' with seamless connections to optical fiber networks." The frequency bands and associated applications intended to be supported include 3-60 GHz for mobile video, 30-300 GHz for WLAN (Wireless LAN) and high quality TV, 5 GHz for WLAN and ATM access, and 3-60 GHz for Wireless Home-Link. The MMAC Systems Promotion Council includes well over 100 vendors, most of which are Japanese companies.


Multimedia Communications Forum. Formed in June 1993, the MMCF is an nonprofit research and development organization of telecommunications service providers, multimedia application and equipment developers, and end users who realize the revolutionary potential of multimedia communications. Forum members are dedicated to accelerating market acceptance and multivendor interoperability of multimedia communications worldwide. MMCF acts as a central clearinghouse for all multimedia communications-related standards, specifications and recommendations.


Microwave Multi-point Distribution System or Multipoint Multichannel Distribution Service. Irrespective of what the acronym means, the definition is the same. MMDS is a way of distributing cable television signals, through microwave, from a single transmission point to multiple receiving points. Often used as an alternative to cable-based cable TV. According to an April, 1995 press release from Pacific Telesis, which was starting an MMDS service, "in digital form, it will provide more than 100 channels to a radius of approximately 40 miles from the transmitter. The MMDS transmitter delivers video to homes that are in its 'line of sight.' MMDS transmissions are limited by the terrain and foliage of a given market. The microwave signal is received by an antenna on the subscriber's home, then sent down coaxial cable to a box atop the customer's TV set. The box decodes and decompresses the digital signal." MMDS is increasingly being called "Wireless Cable." See Wireless Cable.


Mobility Management Entity.


Multi-Mode Fiber. Due to its relatively thick inner core (25-200 microns) MMF allows light signals to travel in many modes (i.e., physical paths). Some portions of light pulses travel more or less down the center of the inner core; some disperse (i.e., spread out) and strike the edges of the core, at which point they are reflected back into the core by the cladding; and some actually enter the cladding and travel through it for a distance before they re-enter the core. Some paths are longer than others. The longer the path, the longer the time it takes to travel it. So, some portions of a light pulse arrive at the receiver before some other portions. This phenomenon of "modal dispersion" results in "pulse dispersion," which is the distortion, or smearing, of the individual pulses. There are two types of MMF: step-index fiber and graded-index fiber. MMF usage largely is restricted to application in LANs and FDDI (Fiber Distributed Data Interface), both of which are characterized by relatively short distances and relatively low speeds. Single Mode fiber (SMF), which has a thinner core, is used on long haul, high speed applications. See also FDDI, Graded-Index Fiber, SMF and Step-Index Fiber.


Abbreviation for micromicrofarad; one millionth of a farad, the unit of measuring capacitance.


  1. Man Machine Interface.

  2. Machine Machine Interface. The former is more common.


Microwave Monolithic Integrated Circuit.


Modular Multifunction Information Transfer System. Hiding behind something call the MMITS Forums is a group of people working to define software programmable radios. There are two areas of emphasis:

Handheld ” working with being able to download software into cellular handsets so they can work with a variety of air interfaces.

Mobile ” concentrating on military requirements initially. but looking at the needs of public safety (Police, Fire, etc.) for the future.

The basic idea is to bring PC concepts to the radio world by moving the Digital/Analog ” Analog/Digital function very close to the antenna, and do all of the tuning, spread/despread, modulation/demodulation, etc with DSPs.


A six wire modular jack with the locking tab shifted off to the right hand side. Used in the DEC wiring system.


Man Machine Language.


Modified Modified Read data compression method used in newer Group 3 facsimile machines.


  1. Material Management System.

  2. Multimedia Messaging Service. A service that allows cell phone users to send pictures, movie clips, cartoons and other graphic materials from one cell phone to another. According to a press release from Singapore's SingTel's announcement of MMS: "With MMS, SingTel Mobile's postpaid customers can send photos and pictures with integrated text and voice clips from their MMS mobile phones to another mobile phone. Recipients will get an MMS message, if they are using MMS phones, or an SMS notification to retrieve the MMS message via the Internet or email. MMS messages can also be sent directly to email addresses."


Modular Metallic Service Unit.


MultiMedia Telecommunications Association. The successor organization to NATA. MMTA was orignally organized around five divisions ” computer telephony integration, conferencing/collaboration and messaging, LAN/WAN internetworking, Voice/Multimedia and Wireless Communications. MMTA is on 202-296-9800. In November, 1996 MMTA announced its intent to merge with TIA, another Washington organization called Telecommunications Industry Association. On December 15, 1997 MMTA announced that it had been officially combined into the Telecommunications Industry Association. The combination of all these organizations reflected the fact that the telecommunications industry had become competitive, thus depriving many of Washington organizations of their reason for existing. See also See ACTAS and NATA.


Memory Management Unit. Circuitry that manages the swapping of blocks of memory.


Multiparty Multimedia Session Control. A Working Group (WG) of the IETF (Internet Engineering Task Force) , the MMUSIC is chartered to develop Internet standards track protocols to support Internet teleconferencing sessions. MMUSIC's current focus is on supporting loosely controlled conferences on the MBone, although the protocol are ensured to be general enough to be used in managing tightly-controlled conferences on any IP-based network. Among its accomplishments are the RFCs for Real-Time Stream Protocol (RTSP), Session Announcement Protocol (SAP), Session Description Protocol (SDP), Session Initiation Protocol (SIP), and Simple Conference Control Protocol (SCCP). See also SIP.


A format of rewritable DVD disc proposed by NEC. It stands for Multi Media Video File. For a longer explanation, see DVD-RAM and DVD.


Multimedia Network Applications.


Multiple CCS7 Network Addresses.


Mobile Network Code. A part of the IMSI (International Mobile Subscriber Identity) or LAI.


From the Greek mnemonikos, a shorthand label or term that is easy to remember. A mnemonic is a symbolic representation of an address (e.g., ATL for Atlanta, or DLS for Dallas) or operation code (e.g., JMP for jump). Acronyms are a type of mnemonic; LASER, for instance, is shorthand for Light Amplification by Stimulated Emission of Radiation. See also Acronym.

Mnemonic Dial Plan

Pronounced "nemonic." A way of dialing using characters typed on the keyboard of a terminal. The word Mnemonic comes from the same roots as memory. It's a memory jogging way of remembering something, like a way to dial. See Mnemonic Prompts.

Mnemonic Prompts

System commands represented by the appropriate alphabet letter rather than by a number, (for example, "P" to "Play", "A" to Answer"). See Mnemonic Dial Plan.


Mobile Network Location Protocol.


  1. Microcom Networking Protocol.

  2. Mobile Number Portability.


Error correction protocol for awful communications environments, like cellular networks. Use of MNP10-EC helps prevent disruptive signal fading and reduces the number of dropped calls that occur when you're trying to send data over cell networks. See Microcom Networking Protocol for a greater explanation.


Mobile Network Registration Protocol.


See Magneto Optic Drive.


In North america, the original term for a telephone that worked with cellular service was cell phone. In the rest of the world it was called a "mobile." Eventually America caught up and the industry is now preferring the term mobile to describe a cell phone. The technical term ” i.e. what you find in the industry literature ” is Mobile Station.

Mobile Application Subsystems

MAS. That portion of a Mobile End Systems (M-ES) concerned with the provision of application services. The MAS contains the applications software that is independent of the CDPD network. In most cases, the includes network software.

Mobile Attenuation

The power of the mobile phone can be adjusted (or attenuated) dynamically to one of seven discrete power levels (analog cellular). This is done so that when a mobile comes closer to a base receiver its power is reduced to prevent the chance of interfering with other mobiles operating on the same voice channel in another cell (co-channel interference). Additionally, this is even more important to portable units to keep the transmit power at a minimum to increase the talk usage time before the batteries expire.

Mobile Cellular Phone

See Mobile.

Mobile Cellular Service

A fancy name for cellular phone service or cell phone service. See Cell, Cell Switching, Cellular Radio and IN.

Mobile Communications

Quite simply, the ability to communicate while moving. Wireless technologies like cordless telephony and cellular allow you to communicate on the go. Wired technologies, like copper wire and fiber optics, don't work if you might break the wire, or run out of wire. One of the great stories about mobile communications involves wires. According to William E. Kennard, FCC Chairman, and as included in a speech he made in 1998, the U.S. military faced a problem in 1907. The cavalry needed to communicate when on patrol. So, one horse soldier would ride behind the troops, unreeling wire along the ground. When a message needed to be sent back to the base camp, the soldier would jump off his horse, plant a metal stake in the ground, and send a message via Morse code. This process slowed the progress of the troop. Military engineers came up with a solution. They put a copper patch on the horse's skin. Since a horse always has one hoof on the ground, the circuit was complete. Therefore, the scouts could send a message while riding . (No mention is made of the effect on the horse.)

Mobile Controlled Handoff

This means the decision to initiate a transfer or handoff from one cell to another cell is under the control of the mobile device. Used in CDPD.

Mobile Data

Mobile data is a generic term used to describe data communications through the air from and to field workers ” from package deliverers, to car rental companies (to track cars ), to field service personnel, to law enforcement officials checking license plates.

Mobile Data Base Station

MDSB. Component of the CDPD network that provides data link relay functions for a set of radio channels serving a cell. An MDBS is located in each cell site, and its primary role is to relay data between Mobile End System (MES) and the Mobile Data Intermediate System (MD-IS). it is the stationary network component responsible for managing interactions across the airlink interface.

Mobile Data Intermediate System

MD-IS. The CDPD network element that performs routing functions based in knowledge of the current location of the M-ES. Responsible for CDPD mobility management. A cellular radio term.

Mobile Data Link Protocol

MDLP. The Link Layer protocol used in Cellular Digital Packet Data (CDPD). Provides Temporary Equipment Identifier (TEI) management, multiple frame operation, unidata transfers, exception condition detection with selective reject recovery, etc.

Mobile Digital Voice Channel

MDVC. The channel between a mobile phone and a cell site antenna in a digital cellular or PCS environment. The MDVC supports both voice and data transmission, although the allocated bandwidth is designed primarily to support voice. Signaling and control functions take place over separate channels set aside specifically for that purpose.

Mobile End System

M-ES. An end system that accesses the CDPD network through the airlink interface. The device that allows mobile users to work in an untethered fashion while remaining connected to a data network. The system's physical position may change during data transmission. A cellular radio term.

Mobile Entrophy

My friend is a klutz. He claims that wherever he goes chaos follows.

Mobile Home Function

A Mobile Data Intermediate System, that (1) maintains an information database of the current serving area of each of its homed Mobile End Systems (M-ESs), and (2) operates a packet forwarding service for its homed M-ESs. A cellular radio term.

Mobile Identification Number

When the "SEND" key on a cellular phone is pressed, the phone transmits an origination message to the base station. This message includes the dialed digits and the identity of the calling cellular phone. The calling cellular phone is identified by its Mobile Identification Number (MIN), which is usually the same as its ten-digit phone number. See also ESN.

Mobile IP

An emerging set of extensions to the Internet Protocol for packet data transmission, Mobile IP is intended to serve nomadic users connecting on a wireline, rather than a wireless, basis. Mobile IP is being developed by the IETF (Internet Engineering Task Force) to operate much like a highly secure and dynamic packet data communications version of a postal service forwarding address. The benefit is that the nomadic user will not have to continually change IP addresses and reinitialize sessions. The IETF (Internet Engineering Task Force) defines Mobile IP as enabling an IP device to roam across networks and geographies, while remaining constantly connected as if always attached to its home location _using_the_same_IP_address_ (emphasis supplied). It will work like this:

The mobile node will have one permanent address and another for location purposes and another for identifying it to other network nodes. Data will be transmitted to the permanent address, associated with the "home agent." When the nomadic node is traveling, the "home agent" will forward the data in care of the "foreign agent," the IP server serving the foreign subnet, through a process of encapsulating that data with another IP address contained in a data header preceding the original packet. Once the data packets are received by the foreign agent, the additional header will be removed through a process known as decapsulation. Should the node relocate yet another time, both the "home agent" and the previous foreign agent will be advised of that fact; thereby, inflight packets can be forwarded by the previous foreign agent to the new foreign agent through a process known as "smooth handoff." While there currently is no Mobile IP standard being developed for wireless mobility, Mobile IP promises to make life easier for users that roam from location to location within a multisite corporate enterprise. See also IP.

Mobile Multimedia Access Communication


Mobile Mounting Kit

An optional cellular phone accessory that allows a transportable or portable to be connected to a vehicle's power supply and antenna lead, thereby boosting power and improving reception . Sometimes referred to as a car kit or car mounting kit. Some of these kits are very expensive. Check the price of the kit before you buy your phone.

Mobile Network Location Protocol

MNLP. A cellular radio term. In the CDPD network, the MNLP is the protocol used between the Home Mobile Data Intermediate System (MD-IS) and the Serving MD-IS and it used to keep the Home MD-IS updated on the location of a Mobile End System (M-ES) (i.e. the location of the cell phone).

Mobile Network Registration Protocol

MNRP. In the CDPD cellular radio network, protocol used between the Mobile End System (M-ES) and the Serving Mobile Data Intermediate System (MD-IS) to announce the M-ES's Network Entity Identifier (NEI) and to confirm the service provider's willingness to provide service.

Mobile Number Portability

MNP is a set of processes by which you eventually might be able to change your cellular or other wireless service provider, and retain your telephone number. MNP essentially is the mobile wireless version of LNP (Local Number Portability). See LNP for lots more detail.

Mobile Phone

Another name for a cellular phone. There are four main types of cellular phones ” mobile (also called car phone), transportable, portable and personal. A mobile phone is attached to the vehicle, the vehicle's battery and has an external antenna. The mobile phone (the car phone) transmits with a standard three watts of power. Mobile telephone service is provided from a broadcast point located within range of the moving vehicle. That range is called a "cell." The broadcast point in turn is connected to the public network so that calls can be completed to or from any stationary telephone, i.e. one connected to a land line. See Cellular and Car Phone.

Mobile Phone Jammer

A device which transmits radio waves at cell phone frequencies causing it to jam communications between cell phones and their base station. The main purpose of a mobile phone jammer is to stop cell phones from receiving phone calls. The first mobile phone jammer came out of Israel in the summer of 1999. Costing around $1000, the device allegedly shut off all phone calls coming into cell phones in a room. Customers for such devices include recording studios , cinemas and concert halls. There is some speculation that the device may be illegal.

Mobile Serving Function

MSF. A Mobile Data Intermediate System (MD-IS) function that (1) maintains an information database of the Mobile End Systems (M-ES) currently registered in the serving area, and (2) de-encapsulates forwarded packets from the MHF and routes them to the correct channel stream in a cell where the destined M-ES is located.

Mobile Switching Center

MSC. The location of the Digital Access and Cross- connect System (DACS) in a cellular telephone network.

Mobile Station

See Mobile.

Mobile Station Roaming Number


Mobile Telecommunications Sourcing Act

This law, signed by President Clinton on July 28, 2000 enables states to source cellular calls for tax purposes, only at the customers place of "primary use". For residential customers the place of primary use is their home address, while for business customers it is their primary business street address. The effect of the law is that if a cellular user has a home residence in State A , their place of primary use, but originates an interstate call in State B, only State A can assess sales tax on the call.

Mobile Telematics

Sometimes just called telematics. It involves integrating wireless communications and (usually) location tracking devices (generally GPS) into automobiles. The best known example is GM's OnStar system, which automatically calls for assistance if the vehicle is in an accident . These systems can also perform such functions as remote engine diagnostics, tracking stolen vehicles, provide roadside assistance, etc.

Mobile Telephone Exchange

MTX. The Northern Telecom term for MTSO (Mobile Telephone Switching Office).

Mobile Terminated

The term used to describe a call where the destination of the call is a mobile (i.e. cellular) telephone.

Mobile Unit

The cellular telephone equipment installed in a vehicle. It consists of a transceiver, control head, handset and antenna.


A "unified" cellular phone service covering 83% of North America's population. It is a consortium of six Bell cellular operators and some Canadian cellular operators.

The idea is simple. Anyone calling a subscriber of one of these companies would have his call automatically routed to the subscriber, no matter where in Mobilink that subscriber was. Before Mobilink, you had to know where the person was you wanted and then dial a bunch of complex codes to get to him.


Mobitex is a packetized narrow-band data service, originally conceived by Swedish Telecom and further developed by Eritel, a joint venture of Swedish Telecom and Ericsson. The service is being offered in the United States by RAM Mobile Data/ Bell South. Base stations , which typically cover 5-15 mile radii, are arranged in a cellular-like fashion. The technical details of Mobitex, collectively referred to as the Mobitex Interface Specification or MIS, can be obtained from any operator of a public Mobitex network or from Ericsson directly. Mobitex is an open, non-proprietary system but the specification is copyrighted and is made available under a royalty-free license. The MIS is not in the public domain. All Mobitex networks operate in one of three frequency families: 80 MHz, 400 MHz, or 900 MHz. Frequencies and channels are generally assigned by a national government authority; each local operator can tell you the specific channel assignments for its country. There are 29 Mobitex networks around the world, in 22 countries on six continents. Some of the networks are operated publicly (that is, you may buy network service from the local operator) while others are owned and operated by companies for their own use and benefit.


Slang for MOtherBOard.


Mobile Originating Call. A cellular phone term. MOC refers to the central office where the outbound leg of a call begins. See also MTC.

Modal Dispersion

Also known as Differential Mode Delay (DMD), modal dispersion can be thought of as the blurring of the input signal in a fiber by the several modes (paths) that the signal may take as it propagates through (transverses) a fiber. Each light pulse in a digital optical fiber system begins life as a distinct pulse created by a light source, such as a Light-Emitting Diode (LED) or a Laser Diode, with laser diodes being used in the high-speed, long-haul systems. As each pulse propagates through the thin and very pure inner core of the fiber, it naturally spreads out. The inner core is surrounded by a layer of "cladding," glass of a slightly different refractive index which serves to bend the light signal back inward. As some portions of the light pulse travel more or less through the center of the core while other portions of the pulse bounce around, they travel different distances from point to point. Therefore, some portions of the light pulse arrive sooner than others. The result of Modal Dispersion is known as "Pulse Dispersion," which is a blurring or smearing of the individual pulses. In other words, the pulses overrun each other, losing their individual identity. The thicker the inner core, the worse the effect. The longer the cable, the worse the effect. The faster the transmission speed, the short the interval between the pulses, and the worse the effect. As Single Mode Fiber (SMF) has a thinner inner core than MultiMode Fiber (MMF), the effect of modal dispersion is less with SMF. See also Collimation, MMF and SMF.

Modal dispersion can be thought of as the blurring of the input signal in a fiber by the several modes that may propagate down a fiber. Each mode may take a separate path down the fiber, and thus that signal may arrive at slightly different times. The dispersion depends on the fiber's internal characteristics and its length. In short, modal dispersion is pulse rounding in lightwave communications that takes place because of the slightly different paths followed by the laser light rays as they arrive at the detector slightly out of phase.

Modal Distribution

In an optical fiber operating at a single wavelength, the number of modes supported by the fiber, and their propagation time differences. In an optical fiber operating at multiple wavelengths simultaneously, the separation in wavelengths among the modes being supported by the fiber.

Modal Loss

In an open waveguide, such as an optical fiber, a loss of energy on the part of an electromagnetic wave due to obstacles outside the waveguide, abrupt changes in direction of the waveguide, or other anomalies, that cause changes in the propagation mode of the wave in the waveguide .

Modal Noise

A source of signal distortion in fiber optic networks, modal noise is power fluctuations in the receivers, and is a result of interactions between the fiber and the connectors when high-power lasers are used to increase transmission distances.

Modbus Protocol

Protocols define the rules by which devices talk with each other. Modbus is an application layer messaging protocol, positioned at level 7 of the OSI model, that provides client/server communication between devices connected on different types of buses or networks. MODBUS is a request/reply protocol and offers services specified by function codes. MODBUS function codes are elements of MODBUS request/reply PDUs.

Modbus protocol was developed by Modicon in 1979 and is used in industrial manufacturing to establish master-slave /client-server communication between intelligent devices.


  1. A mode is a stable propagation of state of an electromagnetic wave in an optical fiber. In rough terms a mode can be thought of bundles of light rays, of the same wavelength, that enter a fiber at the same angle. See Modal Dispersion.

  2. Mode is essentially a switch inside a computer that makes it run like another computer, usually an older one.

Mode Coupling

The transfer of energy between modes. In a fiber, mode coupling occurs until equilibrium mode distribution, EMD, is reached.

Mode Evolution

A fiber optic term. The dynamic process a multilongitudinal laser undergoes whereby the changing distribution of power among the modes creates a continuously changing envelope of the laser's spectrum.

Mode Field Diameter

A fiber optic term. A measure of distribution of optical power intensity across the end face of a single-mode fiber.

Mode Filter

A fiber optic term. A device that removes higher-order modes to simulate equilibrium mode distribution.

Mode S

Discrete addressable secondary radar system with data link.

Mode Scrambler

A fiber optic term. A device that removes cladding modes.


  1. Acronym for MOdulator/DEModulator. Conventional modems comprise equipment which converts digital signals to analog signals and vice versa. Modems are used to send digital data signals over the analog PSTN (Public Switched Telephone Network. Although the carrier switches (e.g., central offices and tandem offices) are typically digital, as is the backbone transmission network (e.g., T-carrier), the local loop always is analog unless the user orders a more costly digital loop (e.g., ISDN or T-1). Therefore, the PSTN is analog as far as most people are concerned.

    Conventional modems work like this. Your PC outputs data in the form of "1's" and "0's" which are represented by varying levels of voltage. The modem converts the digital data signal into variations of the analog sine wave so the data can be transmitted over the PSTN. A matching modem on the other end reverses the process in order to present the target device with a digital bit stream. The modulation techniques include some combination of Amplitude Modulation (AM), Frequency Modulation (FM) and Phase Modulation (PM), also known as Phase Shift Keying (PSK). Used in combination, these techniques allow multiple bits to be represented with a single (or single set) of sine waves. In this fashion, compression is accomplished, which allows more data to be transmitted in the same period of time and which therefore reduces the connect time and the associated cost of the data transfer. Contemporary, conventional modems are standardized by the ITU-T as part of the "V" series of standards. Such modems are characterized by error detection and correction mechanisms, adaptive equalization, internal dialing, and numerous other sophisticated capabilities. 56 Kbps modems are the latest development in the world of conventional modems; they remain to be standardized. The term "modem" also is applied (and correctly so, in the purely technical sense) to ISDN TAs (Terminal Adapters), ADSL TUs (Terminating Units), line drivers and short-haul modems. The last two, in fact, are voltage converters.

    See also Line Driver, Modem Eliminator, Modem Pool, Modem Standards, Modulation Protocols, Serial Port, Short-Haul Modem and 56 Kbps Modem.

  2. According to the Vermonters' Guide to Computer Lingo, modem is what landscapers do to dem lawns. (This is a joke.)

Modem Bonding

A term which describes the bonding, or linking, of two 56 Kbps modems over two phone lines to double the performance. This process is accomplished through matching devices, one on each end of the connection; each modem operates at its maximum achievable rate, with the aggregate rate being roughly double that of each individual modem. Theoretically, modem bonding can yield speeds of as much as 128 Kbps downstream and 67.2 Kbps upstream, although the FCC currently limits maximum downstream performance through each modem to 53 Kbps, for a total of 106 Kbps. Modem bonding technologies are proprietary. See 56 Kbps Modem.

Modem Cowboy

A slang term for someone who typically lives in the mountain states of Western America and does most of his work via modem.

Modem Eliminator

A wiring device designed to replace two modems; it connects equipment over a distance of up to several hundred feet. In asynchronous systems, this is a simple cable. Here is a specific application using a Modem Eliminator: You can connect a PC to a printer, or a PC to another printer using a cable. But you can only go a certain distance ” maybe 100 feet. After that, the traditional solution has been to use a modem and go over traditional phone lines. Instead, you can connect the two devices directly by wire using a Modem Eliminator. There are two advantages of a Modem Eliminator over a normal modem. The eliminator is cheaper and it can often transmit faster. According to Glasgal Communications, there are many cases where it is either unnecessary, cumbersome or too expensive to interconnect terminals using modems or line drivers in an experimental or a very short-haul environment. A modem eliminator functionally resembles two modems back-to-back on a leased line and therefore saves the cost of two modems and a line in many situations.

Modem Fallback

When the telephone line quality is not good enough to accommodate the top rated speed of a modem ” for example 14,400 bps ” the modem drops down to lower speeds ” initially to 9,600 bps, then if necessary, to 4,800 bps, or even down to 2,400 bps.

Modem On Hold

See V.92.

Modem Pair Delay

The one way delay added by a pair of modems to the propagation delay on a communications line.

Modem Pool

A collection of modems which a user can dial up from his terminal, access one and use that one to make a data call over the switched telephone network. Modem pools are obviously designed to allow many users to share few modems, thus saving on modems. Now that modems have become less expensive, the advantages of modem pooling are no longer as great. There are also some advantages in having a modem right next to your terminal or computer ” namely you can see how it is functioning. And modems have lights to indicate what they're doing. One of the most useful lights on most modems indicates whether the line is "off hook" or not. It is possible for your computer to instruct your modem to hang up the line and for your modem to forget to do it, leaving you with a huge phone bill. One problem with giving people their own modems is they (the modems) have a tendency to get pinched. It's hard to screw down modems. Harder, anyway, than computers and disk drives.

Modem Server

A networked computer with a modem or group of modems attached to it that allows network users to share the modems for outbound calls.

Modem Sharing Unit

MSU. A hardware device, most often a simple contention switch operating on RTS (Request to Send) leads to DTE interfaces, that permits only one terminal at a time to use the modem.

Modem Standards

Definitions of electrical and telecommunications characteristics which enable modems from dissimilar manufacturers to speak to each other. Bell 103...US standard for 300 bps; ITU-T V.21...International standard for 300 bps; Bell 212A...US standard for 1200 bps; ITU-T V.22...International standard for 1200 bps; ITUT V.22 bis...US and international standard for 2400 bps; ITU-T V.23...International videotex standard (1200/75 bps or 75/1200 bps). See also Hayes Command Set and V.Series recommendations, i.e. V.34.

Modem Turnaround Time

The time needed for a half-duplex modem (an old-fashioned one) to reverse its transmission direction.


See V.92.

Moderated Mailing List

A mailing list where messages are first sent to the list owner before they are distributed to the subscribers.


A moderator is a person who controls what gets posted to a particular Internet newsgroup, A moderator is used to ensure that a newsgroup's article stick to the agreed upon subject matter. A newsgroup may or may not have a moderator.

Newton[ap]s Telecom Dictionary
Newton[ap]s Telecom Dictionary
ISBN: 979387345
Year: 2004
Pages: 133 © 2008-2017.
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