Modified Final Judgment-MZI | Newton[ap]s Telecom Dictionary

Modified Final Judgment

MFJ. The agreement reached on January 8, 1982 between the United States Department of Justice and AT&T approved by the courts on August 24, 1982 that settled the 1974 antitrust case of the United States versus AT&T. The MFJ divested AT&T of the local regulated exchange business and created seven regional holding companies ” Ameritech, Bell Atlantic, Bell South, NYNEX, Pacific Telesis, Southwestern Bell and US West. The MFJ placed restrictions on the local exchange carriers , namely that they couldn't get into long distance communications. The Modified Final Judgment did not prohibit AT&T from providing local telecommunications, it prohibited AT&T from purchasing the stock of the divested RBOCs.

Modified Finite Queue

A traffic engineering term . Erlang C assumes an infinite queue, that is, callers will wait indefinitely to have their call answered . Since this is obviously not the case, some parties have suggested that a different algorithm should be used in order to produce more accurate forecast. In practice, while Erlang C will produce some degree of overstaffing based on its assumption of infinite queuing, alternatives that assume finite queues result in understaffing. Since most call centers would prefer slight overstaffing, and a greater likelihood of meeting grade of service, to understaffing, with a greater degree of customer dissatisfaction, Erlang C continues to be the preferred and recommended algorithm. the modulated signal to the frequency of a sinusoidal modulating signal. The modulation index is numerically equal to the phase deviation in radians.

Modulation Protocols

Modem stands for MOdulator/DEModulator. A modem converts digital signals generated by the computer into analog signals which can be transmitted over an analog telephone line. It also transforms incoming analog signals into their digital signals for inputting into a computer. The specific techniques used to encode the digital bits into analog signals are called modulation protocols. The various modulation protocols define the exact methods of encoding and the data transfer speed. In fact, you cannot have a modem without modulation protocols. A modem typically supports more than one modulation protocol. The raw speed (the speed without data compression) of a modem is determined by the modulation protocols. Here are the main internationally accepted modulation protocols:

Modified Frequency Modulation

MFM. 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.

Modified Huffman

MH. A one-dimensional data-compression scheme that compresses data in a horizontal direction only through a process known as "run-length encoding. All Group 3 fax machines support MH, which is the lowest common denominator compression algorithm. MH scans each line of a document, looking for redundant data, i.e., the same color repeated. A document typically includes lots of white space, which MH interprets as redundant data. Rather than sending 1,728 bits of "nothing" across the circuit, MH sends a 9-bit code value, thereby compressing the data by a factor of 192. While the actual level of compression achieved, of course, depends on the amount of redundant data in a document, MH compression reduces transmission time and saves money. MH supports relatively slow fax transmission at 9.6 Kbps, or about 30 seconds per page. Group 3 standards also include Modified Read (MR) and Modified Modified Read (MMR), which are successively more efficient. All Group 3 fax machines support MH, which is the lowest common denominator compression technique. See also Compression, Huffman, Modified READ, and Modified Modified READ.

Modified Read

MR. Modified READ (Modified Relative Element Address Differentiation) is a two-dimensional coding scheme for facsimile machines that works both horizontally and vertically, using the previous line as a reference. In other words, Modified READ scans each line, compressing out redundant data, much as does Modified Huffman. Modified READ then compares each line to the previous line, further compressing out redundant data. Some Group 3 fax machines use MR, which improves on Modified Huffman, assuming that a document has data continuity up and down, as well as from left to right. MR supports "business letter" quality transmission to about 20 seconds per page. See also Compression, Modified Huffman, and Modified Modified READ.

Modified Modified READ

MMR. An improvement on Modified READ (MR), MMR supports the "business letter" quality transmission time of a Group 3 fax machine to about 10 seconds per page. All fax machines which operate at 14.4 Kbps use MMR, as do some high-volume machines which operate at 9.6 Kbps. See also Compression, Modified Huffman, and Modified READ.

Modular

Equipment is said to be modular when it is made of "plug-in units" which can be added together to make the system larger, improve its capabilities or expand its size . There are very few phone systems that are truly modular.

Modular Breakout Adapter

Allows the technician to access each individual conductor of a cable. Sometimes called a "banjo clip." It's a rectangular plastic box, with conductors on the sides and a modular plug at the long end.

Modular Cord

A cord containing four twisted pairs of wires with a modular plug on one or both ends.

Modular Jack

A device that conforms to the Code of Federations, Title 47, part 68, which defines size and configuration of all units that are permitted for connection to the public telephone network.

Modular Plug

Connecting devices adopted by the FCC as the standard interface for telephone and data equipment to the public network. These are the plastic "ends" you see on cables. They come in two conductor, four, eight and six. Two, four and six conductor plugs are the same physical size, and are usually used for telephone voice and low speed data communications. Eight conductor (four pair) plugs are wider, and most often used for data, e.g. Ethernet LAN connections. There are several wiring configurations for modular plugs. The most common are T568A and T568B. See UTP Cable.

It's important to match the modular plugs to the type of cable you are using. Plugs made for stranded cable will not work with solid conductor wire because they're designed to pierce the cable in-between the strands. Used with a solid conductor cable, they don't pierce the cable and just get smashed. Plugs made for solid conductors usually work with stranded cable. But I wouldn't recommend trying.

Modulated Waves

Alternating current waves which have their amplitude varied periodically. The signals transmitted by a radio station are examples of a modulated wave.

Modulation

The process of varying some characteristic of the electrical carrier wave as the information to be transmitted on that carrier wave varies. Three types of modulation are commonly used for communications, Amplitude Modulation, Frequency Modulation and Phase Modulation. And there are variations on these themes called Phase Shift Keying (PSK) and Quadrature Amplitude Modulation (QAM).

Modulation Index

In angle modulation, the ratio of the frequency deviation of the modulated signal to the frequency of a sinusoidal modulating signal. The modulation index is numerically equal to the phase deviation in radians.

Modulation Protocols

INTERNATIONALLY ACCEPTED MODEM MODULATION PROTOCOLS
Standard	Speed	Modulation	Duplex	Symbol Rate	Bits per symbol
Bell 103	300	FSK	Full	300	1
v.21	300	FSK	Full	300	1
v.22	1200	DPSK	Full	600	2
v.23	1200/75	FSK	Half	1200	1
Bell 202	1200/75	FSK	Half	1200	1
Bell 212A	1200	DPSK	Full	600	2
v.22bis	2400	QAM	Full	600	4
v.32	9600	QAM	Full (EC)	2400	4
v.32bis	14400	TCM	Full (EC)	2400	6
v.32ter	19200	TCM	Full (EC)	2400	8

Two modems can establish a connection only when they support the same modulation protocol. A modem with a proprietary modulation protocol can only establish a connection with another modem which also supports that modulation protocol. That protocol is typically from the same manufacturer, or from one of several manufacturers that say they are supporting it. For example, there once was a modulation protocol called V.FAST, which delivered 28.8 Kbps over normal analog phone lines. Several manufacturers supported it. Later, the ITU-T came out with V.34. Every modem maker adopted it and V.FAST went away, leaving some modem owners with modems that only worked at 28.8 Kbps with other proprietary modems.

Modulation Rate

The reciprocal of the measure of the shortest nominal time interval between successive significant instants of the modulated signal.

Modulation Suppression

In the reception of an amplitude-modulated signal, an apparent reduction in the depth of modulation of a wanted signal, caused by presence, at the detector, of a stronger unwanted signal.

Modulator

A device which converts a voice or data signal into a form that can be transmitted.

Modulo

Term used to express the maximum number of states for a counter. Used to describe several packet-switched network parameters, such as packet number (usually set to modulo 8 ” counted from 0 to 7). When the maximum count is exceeded, the counter is reset to 0.

Modulo N

In communications, refers to a quantity, such as the number of frames or packets to be counted before the counter resets to zero. Relates to the number of frames or packets that can be outstanding from a transmitter before an acknowledgement is required from the receiver. Also indicates the maximum number of frames or packets stored, in case a retransmission is required (i.e., Modulo 8 or Modulo 128).

Modulus 10

A modulus is a constant number or coefficient that expresses in numerical terms the extent to which a property is possessed by a substance or body. For example the LUHN formula, a form of Modulus 10 (also known as Mod 10), is a method of validating the number on a credit card or debit card when you swipe it through a card reader. Before the credit card transaction is sent over the network for authorization, the card reader performs an algorithm (i.e., calculation) on the number contained on the magnetic stripe. The result of the calculation is compared to a check digit, which is the last number on the card. If the process results in a match, the transaction is forwarded over the network for validation. If the numbers don't match, there is no need to forward the data. Modulus 10 is used in Canada to validate a Social Insurance Number (SIN). There are lots of other applications for this concept.

Here is the way that credit card numbers work: The first set of digits (1, 2, 3, or 4 digits), from left to right, are the credit card type (e.g., American Express, MasterCard, or Visa). The middle numbers are identify the issuing bank and the customer. The last digit is the check digit.

Here is the way the LUHN formula works for credit card validation:

Starting with the second to the last digit and moving right-to-left , multiply every other digit by two. If any resulting number is two digits, add the two digits together. For example, 7x2=14, and 1+4=5.
Add all of the digits skipped in the first step.
Add together the results of the first two steps.
The results of the third step must be a number that ends in zero.

MOH

Music On Hold.

Moire

In a video image, a wavy pattern caused by the combination of excessively high frequency signals. Mixing of these signals causes a visible low frequency that looks a bit like French watered silk, after which it is named.

Moire pattern

Wavy distortions, most obvious in image areas filled with solid color, that result from interference between the screen's phosphor layer and image signal.

Moisture Barrier Bag

MBB. A three-ply bag with characteristics that allow minimal moisture transmission, thereby preserving plastic surface-mount packages, which are packed into the bag, in a dry state.

Moisture Resistance

The ability of a material to resist absorbing moisture from the air or when immersed in water.

MOJO

The Legend of Mojo, from a web site called, citycelebrations.org. is told: Generations of Southerners have told stories of a quiet, well-dressed man wandering into town whistling an unidentifiable tune. His quick smile and endless supply of charm were legendary. Some stories say that he was aristocratic, others that he was a self- educated farmer. Wherever he went, the well-dressed stranger always carried a small leather bag filled with golden coins called Mojo. Legend has it that the golden Mojo came from the Fountain of Youth in what is now known as Florida. The mysterious golden Mojo had the reputation of imparting the owner boundless charm, wit and sophistication. In his travels , the well-dressed wanderer was known to encounter poor souls run down by life and at the end of their ropes . He would stop, carefully remove the leather pouch from his pocket and take out a single golden Mojo and place it face up in the palms of their hands. Some of history's most memorable characters were said to have "Mojo in their pockets" to explain how they became great leaders , social figures and influential artists . As the years went by, the term "Mojo" was simply believed to mean that the person possessed a great deal of personal charm and drive to succeed. Until recently that is... A small golden coin was found buried deep in the mud at the bottom of the canal this past year. Collectors and historians were unable to identify the origins of the metal or the design of the coin. It took the eyes of a very old woman spotting the coin among the collected caps, spoons and buttons found in the canal. "Mojo?" she asked. Yes, Mojo. It has been in Richmond's canal all these years. And now you can experience Mojo for yourself.

Thus MOJO defined,

A magic charm or spell.
An amulet, often in a small flannel bag containing magic items.
Personal magnetism ; charm.

Molding Raceway Method

A cable-distribution method in which hollow metal or wood moldings support cables. Small sleeves of pipe are placed in the wall behind the molding to allow cable to pass through the wall.

Molecular Beam Epitaxy

See Epitaxy.

MOM

Message Oriented Middleware. See MOMA.

MOMA

Museum of Modern Art. www.moma.org.
Message Oriented Middleware Association. According to MOMA, an international not-for-profit association of vendors , users and consultants focusing on the promotion of the use of messaging middleware to provide multi-platform, multi- tier message passing and queuing services for distributed computing architectures. MOMA serves as a point of interchange for experiences and ideas related to the development of MOM, as well as a point of concentration for interoperability and technology requirements toward influencing appropriate standards bodies. MOMA also directs its attention toward promotion of functional interoperability between applications built using disparate message-passing tools and mechanisms. See Middleware and MOM. http://198.93.24.24 (I'm sure that they would have preferred www.moma.org, but the Museum of Modern Art got there first. Hence the use of an IP address for MOMA's Web site, rather than a URL.) See IP and URL.

Monaural sound

Sound reproduction in which only one channel of sound is used. Compare with stereo sound in which two channels of sound are used and heard . The two channels may be different ” to simulate the full depth you might hear in a concert hall. In a monaural headset, you hear out of one ear. In a biaural telephone headset, however, you hear out of two ears. Those channels will, however, be the same, since telephones transmit only one channel of sound.

Monday

According to statistics, Monday is the favorite day of the week to commit suicide.

MONET

Multiwavelength Optical Network. A high-end fiber optic testbed network on the US East Coast . The $100 million project, funded by ARPA (Advanced Research Projects Agency), is intended to test DWDM (Dense Wavelength Division Multiplexing), a means of increasing the capacity of SONET fiber optic transmission systems through the multiplexing of multiple wavelengths of light. MONET participants include AT&T, Bell Atlantic, Bellcore, BellSouth, Lucent Technologies, NRL (Naval Research Lab), NSA (National Security Agency), Pacific Telesis, and Southwestern Bell. See also DWDM, WDM, and SONET.

Money Laundering

According to the New York Times, money laundering is a legal catch phrase that refers to the criminal practice of taking ill-gotten gains and moving them through a sequence of bank accounts so they ultimately look like legitimate profits from legal businesses. The money is then withdrawn and used for further criminal activity. The reason I have included this definition is that the monies being laundered typically make extensive use of telecommunications ” especially moving monies electronically .

Money Market Funds

Funds that invest in Treasury bills (T-bills) and the highest grade government obligations.

Money Suck

"Net Guide" Magazine before CMP closed it down was referred to internally as a "money suck," i.e. it was consuming vastly more money than it was bringing in.

Monitor

To listen in on a conversation for the purpose of determining the quality of the attendant's or agent's response and politeness to customers.
Video monitor. Computer or TV screen and surrounding electronics. As computers have become more powerful so the quality of the monitor they can drive has become more crammed with more information, also called pixels. My own experience with ever newer computers pretty well follows the path of this chart, showing the increasing quality of computer screens and the chips that drive them. I am currently writing this edition on a laptop which is displaying 1,280 by 1,024 pixels on its screen. It's pretty awesome . The quality of viewing photos and artwork is much improved.

PC SCREEN ENCODING

CGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 x 200

Enhanced CGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .640 x 400

EGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640 x 350

Hercules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720 x 348

VGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640 x 480

Super VGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800 x 600

8514/A (also called XGA) . . . . . . . . . . . . . . . . . . . . . . . . . . 1,024 x 768

I don't know the name . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,280 x 1,024

I don't know the name . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,600 x 1,200

I don't know the name . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,800 x 1,440

I don't know the name . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,040 x 1,664

Monitor On Hold

A telephone feature. If the person you're speaking with puts you "on hold," you can turn your speaker on your phone and hang up your handset but keep listening until the other person comes back to the phone.

Monitoring Device

Records data on calls placed through a company's telephone system.The monitoring device will record the numbers called, the length of the calls, the number of calls abandoned .

Monochromatic

Consisting of one color or wavelength. Although light in practice is never perfectly monochromatic, it can have a narrow wavelength.

Monochrome Monitor

A monitor with 720 x 348 pixel resolution in a single color. Most monochrome monitors display in paper white, green or amber.

Monomode Fiber

Another term for Single Mode Fiber (SMF). See SMF.

Monopole

A slender self-supporting tower on which wireless antennas can be and are placed. See Monopole Colocation.

Monopole Colocation

Monopole colocation is having many antennas share one monopole ” a slender self-supporting tower on which wireless antennas are placed. As you add antennas to one slender pole, you often need to shore the pole with extra stuff ” like structural steel and enhancing the monopole's foundation. If you don't, the wind will blow the monopole over and cell phone service will get even worse .

Monopoly Leveraging

Monopoly leveraging is one of the main charges brought against Microsoft by Department of Justice in its 1998 antitrust suit. Monopoly leveraging is using a monopoly in one area to gain a monopoly in another. According to the Justice Department, Microsoft was using its 90% or so market share in desktop and laptop operating systems to gain a monopoly in the browser market. One wonders if the Federal Government is so uncreative it can't think of anything better to do with its time or money.

Monospaced Font

A font in which all characters have uniform widths. See also Proportional Font.

Month To Month

The standard way of paying for telephone service. Some services now come in "rate stability" packages, which means if you commit to keeping the service for a while ” typically three or five years ” it's cheaper each month.

Monthly Factors

A call center term. A historical pattern consisting of 12 factors, one of each month, that tells the program how much that much that month can be expected to deviate from the average monthly traffic year after year. For example, a monthly factor of .75 means that the month will be 25% slower than average, while a factor of 1.15 means that the month will be 15% busier than average.

MOO

Mud, Object Oriented. One of several kinds of multi- user role-playing environments.

MOON

Magneto Optical On Network.
To drop your trousers, to bend over and to expose your bare backside to the person you're mooning. In the technology business, mooning can be used to tell your competitors in no uncertain terms how much better you're doing." It has become something of an maritime tradition for Larry Ellison's boating rivals to drop their trousers and moon the billion- aire when they pass him at sea. Larry Ellison is founder and head of Oracle, the relationship database maker.

Moore's Law

In the October 10, 2000 issue of the magazine, Business 2.0, the reporter asked George Moore, a co-founders of Intel and the inventor of Moore's Law, "What is Moore's Law, according to you?" George answered, "Moore's Law originally got its name from a paper I published in 1965 where we were looking at the complexity of integrated circuits, and I made what seemed like a wild extrapolation from about 60 components to 60,000 over the next 10 years. It turned out to be amazingly correct, the number of components doubling every year over the decade . And then in 1975, I updated it and said the slope was going to double about every two years, looking forward. Those were surprisingly accurate predictions . But it's gotten to the point now that anything that changes exponentially is called Moore's Law, and I'm happy to take the credit for all of it. When I wrote that paper, the message I was trying to get across was that this was going to be the inexpensive way to do electronics. I didn't have any real feeling that my extrapolation was going to be very precise."

His forecast, which implies a similar increase in processing power and reduction in price, has proved broadly accurate: Between 1971 and 2001, transistor density has doubled every 1.96 years. Yet this pace of development is not dictated by any law of physics. Instead, according to the Economist, "it has turned out to be the industry's natural rhythm, and has become a self-fulfilling prophecy of sorts. IT (Information Technology) firms and their customers wanted the prediction to come true and were willing to put up the money to make it happen. Even more importantly, Moore's law provided the IT industry with a solid foundation for its optimism . In high-tech, the mantra goes, everything grows exponentially. This sort of thinking reached its peak during the internet boom of the late 1990s. Suddenly, everything seemed to be doubling in ever-shorter time periods: eyeballs, share prices, venture capital, bandwidth, network connections. The internet mania began to look like a global religious movement. Ubiquitous cyber-gurus, framed by colourful PowerPoint presentations reminiscent of stained glass, prophesied a digital land in which growth would be limitless, commerce frictionless and democracy direct. Sceptics were derided as bozos "who just don't get it". Today, everybody is older and wiser." See also Cao's Law.

MOP

Method of Procedure. A formal, written procedure detailing a job that will take place. Required for any work on the network. Includes detailed instructions for completing the work and for backing out of trouble or mistakes that may occur. For example, when network engineers extend a network by adding a new node to a SONET ring (or by doing something else) they write a MOP. The MOP tells technicians which circuits to reroute , which cards to swap and when to turn on the new node. These MOPs are essential communication tools for engineers and technicians.
Maintenance Operations Protocol, a DEC protocol used for remote communications between hosts and servers.

MOPS

Millions of operations per second. Refers to a processor's performance. In the case of DVI (Digital Video Interactive) technology, more MOPS translates to better video quality. Intel's video processor can perform multiple video operations per instruction, thus the MOPS rating is usually greater than the MIPS rating.

MOR

Multi-wavelength Optical Repeater. An optical amplifier which increases the distance between network elements in a transmission network. The MOR is used to overcome loss in a network and is often used instead of one or more regenerators, which perform a similar function. Unlike the regenerator which receives a signal and then re-transmits it, the MOR increases the power of a signal by amplifying it. This gives the MOR the ability to operate with more than one wavelength at a time, and with different bit rates (such as OC- 48 and OC-192). The following is from Nortel OC-192 System documentation: MOR amplifiers are designed for a bidirectional network architecture which uses the gain region of erbium doped fiber amplifiers (1528.40 nm - 1561.00 nm). Each bidirectional channel consists of counter-propagating wavelengths, one direction in the RED Band (1547.5 - 1561.0 nm) and the other direction in the BLUE Band (1528.4 - 1542.5 nm). The MOR amplifier can be used either as a post/pre-amplifier or as a line amplifier. The MOR supports eight channel wavelength over a single fiber, with four channels amplified in each direction or transmission. Four wavelengths are assigned to co-propagate in the Blue Band, and four wavelengths are assigned to counter-propagate in the Red Band . This enables a flexible and self-paced network evolution for a total aggregate capacity of up to 80 Gb/s (gigabits per second) on a single fiber.

Moratorium.

A moratorium in the telecommunications world is a period of time that no new service-effecting projects are begun. This includes new installations, reconfigurations, etc. Only emergency maintenance is performed during this period. A moratorium might be called by a phone company, for example, if there has been a natural disaster such as a hurricane .

Morph

Computer animation technique that allows figures to change from one shape to another in increments you choose.

Morphology

A cellular radio term. Morphology describes population density. Higher population densities cover more POPs per cell, leading to economies of scale. Lower densities imply improved propagation characteristics and a greater coverage area.

Morrow, George

George Morrow, a mathematician and programmer, was a member of a group of unorthodox hobbyists who were instrumental in creating the personal computer industry. Mr. Morrow was born in Detroit. He dropped out of high school, but at the age of 28 decided to return to school and received a bachelor's degree in physics from Stanford University and a master's degree in mathematics from the University of Oklahoma. He entered a Ph.D. program in mathematics at the University of California at Berkeley, but was sidetracked by his passion for computers. He started working as a programmer in the computer laboratory at Berkeley in the early 1970's and began attending meetings of the Homebrew Computer Club, an informal group of engineers, programmers, experimenters and entrepreneurs that ultimately spun off dozens of companies that formed the core of the personal computer industry in the 1970's. Initially, most personal computers were sold as kits. Mr. Morrow formed Microstuf, a company in Berkeley, Calif., to sell expansion cards and other computer add-on products to the first generation of personal computer enthusiasts . He would later change the name of the company, first to Thinker Toys and later to Morrow Designs. A self-taught computer designer, Mr. Morrow was involved in the efforts to create and standardize the S100 bus, a hardware design that made it possible for early PC makers to share expansion cards. Morrow Designs thrived when the personal computer became an important tool for small businesses. The first machines ran the Digital Research CP/M operating system. Later, Mr. Morrow introduced a portable computer intended to compete head-to-head with the popular Osborne 1 computer. The Morrow machine matched the Osborne's $1,795 price but offered more bundled software. When I.B.M. began to dominate the PC market, Mr. Morrow was forced to shift to the industry standard. In 1985, his company introduced a popular portable design known as the Pivot and sold the design to Zenith Data Systems. But with the industry becoming increasingly dominated by large electronics companies, Morrow Designs filed for bankruptcy in 1986. See Homebrew Computer Club.

Morse Code

There are (or were) two Morse Codes. One called American Morse Code and one called Continental or International Morse Code. The first one, American Morse code was invented by Samuel F. B. Morse, an American born in Boston, in 1837 for use on the electric telegraph. When the electric telegraph was adopted later in Europe, the code Morse invented was not used. The so-called "Continental" code was devised. This code, among other changes, eliminated the spaced dots for C, O, R, Y and Z and the long dash for L. These changes were needed for the satisfactory use of the early visual "needle telegraph" instruments in Europe wherein a needle swung slowly between right and left positions to indicate dots and dashes. The Continental (or International) Code was adopted as a worldwide standard at the Telegraph Conference in Berlin in 1851. American landline telegraphists, however, steadfastly refused to abandon their Morse Code. According to the history books, there was more to their refusal than just plain American stubbornness. When skilfully handled, the American Morse Code actually transmits information somewhat faster because of spaced dots being used in place of dash combinations for some letters . However, careless sending of American Morse Code will produce more errors. Morse code is referred to as International Telegraph Alphabet 1. Mr. Morse also invented the telegraph and first demonstrated it in 1844. Morse Code was used in landlines and in radio telegraphy to ships at sea. The United States Coast Guard abandoned Morse Code in 1996 and member nations of the International Maritime Organization agreed to officially stop its use by February 1, 1999. The French maritime radio authorities sent their last Morse code message on February 1, 1996. Governments are abandoning Morse code in favor of faster, better radio and satellite voice and data communications. International Morse Code is still widely used by U.S. and foreign amateur (Ham) radio operators.

Morse Code represents letters by combinations of long and short signals. Morse Code can be written in dots and dashes or signaled with flashlights and radio bleeps, or taped and scratched between cells in prison . In 1912, the easily-memorized letters SOS were chosen as the international distress signal. "Save Our Souls" was the catch phrase devised later. You'll notice that in Morse Code, more commonly-used letters, such as vowels , have fewer dots and dashes. You'll also notice that some letters are represented by one dot or dash and some by as many as five. This was not a data transmission code to which you can easily apply error checking and correction. It relied heavily on the skill of the operators for error-checking.

In the American Morse Code, a space was used in five letters, namely, C, O, R, Y and Z. No such spaces are used in the modern Continental or International Morse Code. Also, the letter L was an oddball since it was defined as a long dash almost equal to three standard dashes. In fact, In the International Morse Code, the short pulse is called a dot (only when written), but often referred to as sounding a "dit", and the long pulse is called a dash (only when written), but sounded a "dah". Timing is very crucial in sending Morse Code. A "dit" timing is defined as one time unit, a "dah" must take exactly three time units, a pause between elements is exactly equal to one time unit, a pause between characters is exactly three time units, and a pause between words is exactly seven time units for precise Morse Code generation. Hence, sending the word "PARIS " including a space at the end requires 50 time units, i.e., P=11 units, A=5 units, R=7 units, I=3 units, S=5 units, there are 4 characters spaces worth 3 units each=12 units, and a word space nat the end worth=7 units, hence the total of 50 time units for the whole word. This would sound like this: didahdahdit didah didahdit didit dididit.

The Capitol Records building in Los Angeles is built to resemble a stack of records. A red airplane-warning light atop the structure flashes out the word "Hollywood" in Morse code every 20 seconds or so. All airline pilots are expected to learn Morse Code. The . (dot or dit) is short. The _ (dash) is long.

American Morse Code
A ._	B _...	C .. . (dit dit space dit)
D _..	E .	F ._.
G _ _.	H ....	I ..
J _._.	K _._	L ___ (L is long dash, equal to about three dashes)
M _ _	N _.	O . . (dit space dit)
P .....	Q .._.	R . .. (dit space dit dit)
S ...	T _	U .._
V ..._	W ._ _	X ._..
Y .. .. (dit dit space dit dit)		Z ... . (dit dit dit space dit)

International Morse Code
A ._	B _...	C _._. (dash dit dash dit)
D _..	E .	F .._. (dit dit dash dit)
G _ _.	H ....	I .. (dit dit)
J ._ _ _	K _._	L ._.. (dit dash dit dit)
M _ _	N _ .	O _ _ _ (dash dash dash)
P ._ _.	Q _ _._	R ._. (didahdit)
S ...	T _	U .._ (dididah)
V ..._	W ._ _	X _.._ (dahdididah)
Y _._ _	Z _ _.. (dahdahdidit)

See also Inmarsat, Marisat and Morse, Samuel.

Morse, Samuel

Samuel Finley Breese Morse was born in Charlestown (now a part of Boston) on April 27, 1791. He entered Yale University at the age of 14 and graduated in 1810. Although he attended lectures on electricity while at Yale, after graduation he went to England to study art. He returned to the United States in 1815 and became a well- known painter. In 1832, while returning from Europe, he and a fellow passenger discussed the electromagnet and Morse conceived the idea of his telegraph. He made a working model about 1835, filed for a patent in 1838 and in 1844 inaugurated public service between Washington and Baltimore with his famous message, "What hath God wrought?" Morse made such an impression that in 1839 he became the first U.S. citizen to be photographed. He died in 1872. See Morse Code.

MORT

AT&T's database of its dead employees .

MOS

Metal Oxide Semiconductor. Technology describing a transistor composed of a semiconductor layer including "source" and "drain" regions separated by a channel. Above the channel is a thin layer of oxide and over that a metal electrode called a gate. A voltage applied to this gate controls the current between the source and drain regions , or in another format, stops a flow between the two areas.
Mean Opinion Score. If you want to measure the quality of a VoIP call, there are methods, including the Median Opinion Score (MOS) test, endorsed by the International Telecommunications Union (ITU). MOS involves gathering people into a room to listen to calls, after which group members rate quality on a scale from 1 to 5. Voice-quality testing tools based on computer algorithms also are available from vendors such as Agilent and Empirix. MOS is defined in the ITU-T P.800 specification "Methods for Subjective Determination of Voice Quality." P.800 involves the subjective evaluation of preselected voice samples of voice encoding and compression algorithms. The evaluation is conducted by a panel of "expert listeners" comprising a mixed group of men and women under controlled conditions. The result of the evaluation is a Mean Opinion Score (MOS) in a range from 1 to 5, with 1 being "bad" and 5 being "excellent." The components of the MOS are as follows: Opinion Scale: Conversation Test (bad to excellent), Difficulty Scale (yes or no), Opinion Scale: Listening Test (bad to excellent ), Listening: Effort Scale ("No meaning understood with any reasonable effort" to "Complete relaxation possible, no effort required"), and Loudness: Preference Scale ("Much quieter than preferred" to "Much louder than preferred"). A MOS of 4.0 is considered to be "toll quality." PCM (Pulse Code Modulation), the traditional encoding algorithm (ITU-T G.711) used in the circuit-switched PSTN (Public Switched Telephone Network) rates an MOS of 4.4. Following are MOS scores for other widely used speech algorithms: Dual Rate Speed Coder for Multimedia Communication (G.723), 3.5-3.98; Adaptive Differential Pulse Code Modulation (ADPCM, G.726), 4.2; Low Delay-Code Excited Linear Prediction (LD-CELP, G.728), 4.2; and Conjugate Structure-Algebraic Code Excited Linear Prediction (CS-ACELP, G.729), 4.2 See also P.800, P.861 and TELR.

Mosaic

The first graphical Web browser, developed by National Center for Supercomputing Applications, which greatly popularized the Web in the last few years, and by extension the Internet, as it made the multimedia capabilities of the Net accessible via mouse clicks. Mosaic let you surf the Internet's Worldwide Web. Mosaic lets you see hypertext documents with embedded graphics and occasionally sound, movie clips and animation. Mosaic was the first popular software that allowed people to browse around the Web by pointing and clicking. In short, Mosaic is an interface to the WWW (World Wide Web) distributed-information system. Like Gopher, the WWW is functionally split into two parts , the server and the client. Using a GUI (Graphical User Interface) interface (like Mosaic), it has the ability to display:

Hypertext and hypermedia (sounds, movies, extended character sets, and interactive graphics) documents.
Electronic text in an enormous variety of fonts.
Text in bold and italic.
Layout elements such as paragraphs, bulleted lists, and quoted paragraphs. It is mostly distinguishable by its support of multiple hardware platforms, and the WWW HTML (Hypertext Markup Language) document format. Mosaic used to be the most popular Web browser. At the time I wrote this, the most popular one was Netscape and browsers based on Netscape. See Netscape.

MOSS

MIME Object Security Services. An Internet mail security standard which was introduced in 1995 as the successor to PEM (Privacy Enhanced Mail). PEM didn't address MIME (Multipurpose Internet Mail Extension) attachments. MOSS failed to secure widespread support. S/MIME (Secure/MIME), introduced in 1996 has become the de facto standard. See also MIME, PEM and S/MIME.

Most Economical Route Selection

MERS. Used by several phone companies and several manufacturers to mean Least Cost Routing ” the feature of a telephone system which automatically chooses the least cost route for a long distance call. See Least Cost Routing. Synonym: Least Cost Routing.

Most Favored Nation Clause

A clause added to a purchase contract with a vendor saying that for a certain period after signing the contract, if the buyer finds out that the product has been bought for less, then the seller will refund the difference. The idea is to give the purchaser the assurance of the least expensive price.

Most Limiting Capacity

A telephone company term. The arithmetic minimum of (1) Line Capacity (2) Number Capacity or (3) Switching Equipment Capacity.

MOTD

Message Of The Day.

Mother In Law Booth .

You visit a trade show, walk the aisles . You see all the products. One moment, you have a brainwave , "I can do better!" You quit your job, form a company, raise a little money. Twelve months later your shiny new product is ready to exhibit at next year's trade show. But you've run out of money. You need to pay for the booth before the show opens. You've run out of money. You're desperate. You borrow the booth money from your mother-in-law. It comes with a price ” her. She stands in the booth and "helps" you sell your shiny new product. Her salespitch is: "My son-in-law, the genius, has this new thing. Buy it. He needs the money."

Mote

From MIT's Technology Review, "Great Duck Island, a 90-hectare expanse of rock and grass off the coast of Maine, is home to one of the world's largest breeding colonies of Leach's storm petrels-and to one of the world's most advanced experiments in wireless networking. Last summer, researchers bugged dozens of the petrels' nesting burrows with small monitoring devices called motes. Each is about the size of its power source-a pair of AA batteries-and is equipped with a processor, a tiny amount of computer memory, and sensors that monitor light, humidity, pressure, and heat. There's also a radio transceiver just powerful enough to broadcast snippets of data to nearby motes and pass on information received from other neighbors, bucket brigade-style. This is more than the latest in avian intelligence gathering. The motes preview a future pervaded by networks of wireless battery- powered sensors that monitor our environment, our machines, and even us. It's a future that David Culler, a computer scientist at the University of California, Berkeley, has been working toward for the last four years. "It's one of the big opportunities" in information technology, says Culler. "Low-power wireless sensor networks are spearheading what the future of computing is going to look like."

Mother Of

The largest, greatest, grandest, of something. An expression coined in 1990 by Saddam Hussein, Iraqi dictator. The Mother Of all telephone switches would be the largest, most powerful, most elaborate etc. Such a device doesn't exist, as yet ” as, in fact, Saddam Hussein's Mother of all Battles (the one against the Allies in 1990-1991) didn't exist. He lost in the Mother Of all defeats.

Motherboard

The main circuit board of an electronic telephone or computer. The motherboard contains edge connectors or sockets so other PC (printed circuit) boards can be plugged into it. Boards which you stick into motherboards (that's why they're called motherboards) are typically called Fatherboards, because they plug into the Motherboard. Motherboards are also called planar boards . Motherboards are common in key systems and hybrid key/PBXs. They are not common in PBXs, where all the electronics are typically on printed circuit cards which slide into the PBX's cage and which attach to a backplane, which is typically a wiring scheme connecting the PBX's printed circuit cards. See also Daughterboard.

Motif

Motif is the name given to the Open Software Foundation's (OSF) toolkit (Application Programming Interface) and look and feel. Standardized as IEEE 1295, OSF/Motif has become the major GUI (Graphical User Interface) for open computer systems, as defined by The Open Group, a consolidation of the OSP and X/ Open industry consortia. Now in Version 2.0, Motif is the basis of the Common Desktop Environment (CDE) developed jointly by HP, IBM, Novell and SunSoft.

Motion JPEG

JPEG stands for the Joint Photographic Experts Group standard, a standard for storing and compressing digital images. Motion JPEG extends this standard by supporting videos . In motion JPEG, each frame in the video is stored using the JPEG format. See JPEG.

MOTIS

Message Oriented Text Interchange System. Original name for the ISO (International Organization for Standardization) standard now being changed to MHS (Messaging Handling System).

MOTO

Mail Order Telephone Order. A credit/debit card classification by the banking and finance industry reflecting what the banking industry thinks are its highest risk transaction type.

Motorola

According to the family which founded Motorola in the 1920s, the name Motorola was chosen to mean "Music in motion" to signify one of the company's first products ” a car radio.

MOU

Memorandum Of Understanding. In the old days, we called MOUs "Letters of Understanding." But we've become more fancy. We now call them "Memorandum of Understandings." Whatever you call them, they're basically bits of paper which detail out the essence of a legal agreement ” what you will do and what I will do. An MOU is not a legally-binding contract or agreement. Think of it as a document which details what the two of us will do. Once we've agreed and detailed our agreement in a MOU, such document typically makes it to a lawyer, who quadruples its size and its complexity, and makes it into a legal Agreement. Don't tell the lawyers, however: If two of you had signed the MOU and changed its name to an "Agreement," it would be a legally binding agreement. And half the world's lawyers would be out of a job. What a joyous thought!
Minutes Of Use.

Mount

The method in NFS and other networks by which modes access network resources. The word "mount" is often used as a verb, as in my workstation "mounts" the file server, called DALLAS2.

Mounting Cord

The connecting cord between the phone and the jack in the wall. In Europe and North America, it's called a line cord. In North America, it's also known as a mounting cord.

Mouse

A device that generates the coordinates of a cursor or position indicator on your computer screen (e.g. a hand, an arrow) as you move it around on a flat surface, generally in the form of a "mouse pad." The term "mouse" comes from the appearance of the device, as it generally is connected to the mouse input port by a wire which is reminiscent of the tail of a mouse (there also now are wireless mice.) The body of the mouse has one or more buttons which allow you to select objects, icons or text for the performance of certain functions, depending on the application running at the time. This "point-and-click" mode is a critical element of a Graphical User Interface (GUI), such as Windows and its variations; such GUIs were first popularized by Apple Computer.

On the bottom of the mechanical mouse is a ball that rolls on the surface of the mouse pad. In contrast, a trackball is a stationary device with a ball that you move with your finger ” essentially an upside-down mechanical mouse. The mechanical mouse, which is what most of us use, was invented by Douglas Engelbart of Stanford Research Center in 1963; it was commercialized by Xerox in the 1970s.

An optical mouse makes use of a laser to detect the movement of the mouse in relationship to a grid on a special mouse pad. While optical mice are very precise, the also are relatively expensive. Optomechanical mice combine the technologies, without the requirement for the grid pad.

Mouse Blur

Move your mouse quickly across your screen and if you're running an LCD (for example on a laptop), the mouse's pointer will blur ” due to the screen's inability to change as fast as you can move the mouse. Another term for mouse blur is Cursor Submarining.

Mouse Over

See Mouseover.

Mouse Potato

A person who uses his mouse to view educational or entertainment on his computer. Museums are afraid, for example, that if they sell the electronic rights of the art hanging on their walls, every one will stay at home, become mouse potatoes and never visit the museums. The concept of a mouse potato derives from a couch potato ” namely someone who sits on his couch and changes channels on his TV set using a remote device.

Mouse Trap

Ralph Waldo Emerson once said, "Build a better mousetrap and the world will beat a path to your door." Over 300 people in the last 20 years have taken his advice literally by registering improved mousetrap designs with the US Patent and Trade Office, making the lowly rodent- catcher the most re-invented machine in America. The classic, cheap spring-mounted wooden trap, the Victor is the perennial winner, however. One of the problems with many of the "better mousetraps" was that they were so beautiful and so expensive, you had to open them up, remove the dead mouse, clean the trap and re- bait it. All this was offensive. Easier to pick up the dead mouse by the tail and throw it and the cheap mousetrap into the garbage. (Though some would question the morality of it all.)

Mouseover

You're on a Web site. You slide your mouse over a drawing, an illustration, some small object or even a blank spot. Suddenly something happens. You see a new diagram. You see a pop-up. You see some words, e.g. "click here for a great deal." That's called a mouseover. And to see the words, you typically need a Javascript enabled browser. The major ones all are. A mouseover is also called a Rollover.

MOV

Metal Oxide Varistor. A voltage dependent resistor which absorbs voltage and current surges and spikes. This low-cost, effective device can sustain large surges and switch in 1 to 5 nanoseconds. It is used as a surge protector and suppressor . It often the first electronic component that electrons coming in on an incoming phone line hit. Many trunk boards inside PBX are protected by MOVs. If the voltage or current is high, it will blow the MOV, thus protecting the remaining the far more valuable devices on the board.
A Macintosh-based audio/video (multimedia) file. A MOV file has a file extension of .mov and can be played on a Windows operating system if you have the QuickTime Movie Player application installed.

Moves, Adds and Changes

MACs. Any of the above ancillary work performed on a PBX switch, cabinet, or peripheral item after installation. See MAC for a fuller explanation.

Mozilla

In early 1998 Netscape Communications made the source code to its browser publicly available and created the Mozilla project, in which Netscape programmers and volunteers would use the code as the basis for what they hoped would be the ultimate Internet browser. The latest version of Mozilla is available from www.Mozilla.org. Mozilla is now available in 65 languages, with 34 more to follow.

MP-MLQ

MultiPulse-Maximum Likelihood Quantization. A voice compression technique specified in ITU-T G.723.1 (Dual Rate Speech Coder for Multimedia Communications) and Frame Relay Forum FRF.11 (Voice over Frame Relay Implementation Agreement). MPMLQ compresses voice to 6.3 Kbps. See also Dual Rate Coder for Multimedia Communications and VoFR.

MP1

MPEG Layer-1. An extension of the MPEG (Moving Picture Experts Group) standards for compressed digital video, Layer 1 supports CD-quality audio using 4:1 (4-to-1) compression, which reduces the required bandwidth from approximately 1.411 Mbps to 384 Kbps. See MP3 for more detail.

MP2

MPEG Layer-2. An extension of the MPEG (Moving Picture Experts Group) standards for compressed digital video, Layer 2 supports CD-quality audio using compression of 6:1 to 8:1, thereby reducing the bandwidth requirement from 1.411 Mbps to 256-192 Kbps. See MP3 for more detail.

MP3

MPEG Layer-3. MP3 is the most popular audio-compression format on the Internet. MP3 provides an efficient audio-coding scheme, which allows compression of audio files by a factor of up to 12, with little loss in quality from the original CD. For example, a five minute CD song takes about 50 megabytes of storage space on your computer's hard drive. In MP3 format the same song occupies only about 5 megabytes. One of the ways MP3 compression program works is by eliminating tones and frequencies the human ear cannot commonly hear. MP3 is also an extension of the MPEG (Moving Picture Experts Group) standards for compressed digital video. To play MP3 music, you'll need the music. You download it from the Internet or convert it on your PC from your favorite CD. You play your MP3 music on your PC using a software player you downloaded (for free or for pay) from the Internet. Or you can play MP3 music on portable devices, some of which have no moving parts and some of which now sport hard disks. The first MP3 player was Diamond Multimedia's Rio.

MP4

MPEG Layer-4. Rob Koenen, president of the MPEG-4 Industry Forum, which aims to increase adoption of the format, says MPEG-4 (commonly called MP4) is really "a tool- box that may be extended as need be," not a static format. Specifically , the standard consists of eight parts, some of which are still in development. Each part handles different tasks , such as video and audio representation, file format selection and format transfer. Implementation of the standard is left to companies and groups that want to create software or hardware that uses digital video and audio. "The major parts of the standard were [established] a couple of years ago," Koenen said. "Some stuff is still being added ... but there are chips available right now, [and] a number of players already." According to the MPEG-4 Industry Forum's Web site, the standard became usable in 1999, and the parts that have been added since that time do not break the standard. So, although MP4 does not get the kind of press that prior standards have received, it is alive and well. Apple's QuickTime 6, probably the most popular software media player, supports the MP4 file format, and many other companies also are delivering software and hardware products that use the standard. However, some patent and licensing issues remain to be ironed out before the specification is finalized. See Entropic Coding.

MPB

See Meet Point Billing.

MPC

MPOA Client. An ATM term. A protocol entity that implements the client side of the MPOA (MultiProtocol Over ATM) architecture. A MPOA client, typically in the form of a host computer, establishes a VCC (Virtual Channel Connection) with a MPOA server in order either to forward data packets to a destination MPOA client, or to request information so that the originating MPOA client can establish a more direct path on the basis of a cut- through SVC (Switched Virtual Circuit). In this latter case, the server acts as a virtual router. The MPOA client implements the Next Hop Client (NHC) functionality of the Next Hop Resolution Protocol (NHRP). See MPOA.
Multimedia PC. See the following definitions for MPC1, MPC2 and MPC3.

MPC1

Published in 1991, this original Multimedia PC (MPC) specification was adopted worldwide as the basic multimedia extension of the PC standard. MPC standards are established by the MPC Working Group of the SPA (Software Publishers Association). In 1993, MPC1 was followed by MPC2. MPC3, the latest, does not replace MPC2, but takes it one step further. See MPC2 and MPC3.

MPC2

Published in 1993 as the successor to MPC1, MPC2 standards specify elements including:

4MB RAM;
485 SX or equivalent microprocessor of 25 MHz;
hard drive of 160 MB;
CD-ROM drive supporting a sustained transfer rate of 300 KBps, and a maximum average seek time of 400 ms; and
Windows 3.0 plus multimedia extensions, or binary compatibility. No video playback standards were included. See MPC3 for the latest standards.

MPC3

MPC3 is the latest specification (Release 1.3, February 26, 1996) for multimedia PCs as defined by the Multimedia PC Working Group, an independent special interest group of the Software Publishers Association (SPA). Minimum requirements for MPC3 machines include:

8 MB RAM;
CPU which can pass the MPC Test Suite, which is benchmarked on a 75 MHz Pentium;
hard drive of 540 MB;
CD-ROM Drive supporting a sustained transfer rate of 600 KBps and an average access time of 250 ms; and
Windows 3.11 and DOS 6.0 or binary compatibility. MPC3 also adds the requirement for video playback capability compatible with MPEG-1 (hardware or software). See also MPEG.

MPEG

MPEG is commonly known as a series of hardware and software standards designed to reduce the storage requirements of digital video, i.e. video recorded digitally or converted into digital bits. MPEG is most commonly known as an compression scheme for full motion video. The word MPEG is actually the acronym for the Moving Pictures Experts Group, a joint committee of the International Standards Organization (ISO) and the International Electrotechnical Commission (EG). The first MPEG specification, known as MPEG-1, was introduced by this committee in 1991. The common goal of all MPEG compression is to convert the equivalent of about 7.7 meg down to under 150 Kb, which represents a compression ratio of about 52 to one. The two requirements of MPEG-1 are 30 frames per second of Standard Image Format (SIG) of 352 pixels x 240 pixels and CD- quality sound at 44.1 Khz, 16 bit stereo. MPEG image scheme offers more compression than the other poplar JPEG image compression scheme, which is largely for still images. MPEG takes advantage of the fact that full motion video is made up of many successive frames consisting of large areas that are not changed ” like blue sky background. While JPEG compresses each still frame in a video sequence as much as possible, MPEG performs "differencing," noting differences between consecutive frames. If two consecutive frames are identical, the second can be stored in remarkably few bits. MPEG condenses moving images about three times more tightly than JPEG. See also JPEG.

There are two types of MPEG Playback: Software and Hardware. Software MPEG playback is the decompression of MPEG video and audio files using the processing power of the CPU. Hardware MPEG Playback uses an add-in card to deliver full-screen, full-motion, full- color video and CD-quality audio at the full NTSC video frame rate of 30 frames per second, with no dropped frames. The card plays the video from a computer file that has been compressed using the MPEG video standard. Hardware playback is typically much better quality than software playback.

There are actually two MPEG standards: MPEG-1 and MPEG-2. A third, MPEG-4, is currently under development. MPEG -1 is a small-picture mode of MPEG geared to a resolution of 352 by 240 pixels at 30 frames per second (U.S.), with full CD-quality audio. MPEG-1 was originally designed to handle much larger picture sizes than 352 by 240 through interpolation or scaling, but MPEG-2 is more efficient. MPEG-2 offers a "main profile at main level" resolution of 720 by 480 pixels at 30 frames per second (U.S.), with full CD-quality audio. This picture size enables full-screen playback on PCs or TVs. MPEG-2 can incorporate a range of compression ratios, which trade off economies of storage and transmission bandwidth against picture quality. At compression ratios of 30:1 and smaller, MPEG-2 offers the perception of broadcast-quality TV. For greater economy, MPEG-2 supports up to 200:1 compression. MPEG-2 decodes such as the IBM decoder chip can also recognize and decode MPEG-1 bitstreams, enabling the IBM chip to support both compression standards.

MPEG-3 has been dropped. It was focused on HDTV with sampling dimensions up to 1,920 by 1,080 at 30 frames per second. The standard was to address bit rates between 20 and 40 Mbit/sec. Nevertheless, it was discovered that with a little tweaking, MPEG-2 and MPEG-1 work extremely well at the HDTV rate. HDTV is now part of the MPEG-2 High- 1440 Level specification.

MPEG-4 is an ISO/IEC standard developed by MPEG (Moving Picture Experts Group), the committee that also developed the Emmy Award winning standards known as MPEG-1 and MPEG-2. These standards made interactive video on CD-ROM, DVD and Digital Television possible. MPEG-4 is the result of another international effort involving hundreds of researchers and engineers from all over the world. MPEG-4 was finalized in October 1998 and became an International Standard in the first months of 1999. The fully backward compatible extensions under the title of MPEG-4 Version 2 were frozen at the end of 1999, to acquire the formal International Standard Status early in 2000. Several extensions were added since and work on some specific work-items work is still in progress. MPEG-4 builds on the proven success of three fields: Digital television; Interactive graphics applications (synthetic content); Interactive multimedia (World Wide Web, distribution of and access to content) MPEG-4 provides the standardized technological elements enabling the integration of the production, distribution and content access paradigms of the three fields. More information about MPEG-4 can be found at MPEG's home page (case sensitive): http://mpeg.telecomitalialab.com This web page contains links to a wealth of information about MPEG, including much about MPEG-4, many publicly available documents, several lists of 'Frequently Asked Questions' and links to other MPEG-4 web pages. The standard can be bought from ISO, send mail to sales@iso.ch. Notably, the complete software for MPEG-4 version 1 can be bought on a CD ROM, for 56 Swiss Francs. It can also be downloaded for free from ISO's website: www.iso.ch/ittf - look under publicly available standards and then for "14496-5". This software is free of copyright restrictions when used for implementing MPEG- 4 compliant technology. (This does not mean that the software is fee of patents). As well, much information is available from the MPEG-4 Industry Forum, M4IF, http://www.m4if.org. See section 7, The MPEG-4 Industry Forum. This document gives an overview of the MPEG-4 standard, explaining which pieces of technology it includes and what sort of applications are supported by this technology.

A variation on MPEG-4 called MPEG-4 AAC-plug SBR (Spectal Band Replication) is being developed by some firms in order to get "CD-quality" sound at only 48 Kbps into cell phones.

MPEG-1

See MPEG.

MPEG-2

MPEG-2 is one of the most important standards developed by the Moving Pictures Expert Group, an International Standards Organization (ISO) group responsible for the standardization of coded representations of video and audio signals. MPEG-2 has been chosen as a leading digital video compression for a broad range of future video and broadcast applications. See MPEG and MPEG-2 Audio.

MPEG-2 Audio

MPEG-2 audio is a compatible extension of the MPEG-1 audio coding which enables the transfer of mono, stereo, or multichannel audio in a single bitstream. It can operate at data rates from 32 kbps up to more than 1 Mbps, and supports sampling rates of 32, 44.1 and 48 kHz. For stereo, a typical application would operate at an average data rate of 128-256 kbps. A multichannel movie soundtrack requires an average bit rate of 320-640 kbps, depending on the number of channels (5 to 7, plus a sub woofer channel) and the complexity of the encoded audio.

MPEG-3

See MP3.

MPEG-4

See MPEG.

MPG

Microwave Pulse Generator. A device that generates electrical pulses at microwave frequencies.

MPI

MultiPath Interface. Between a transmitter and receiver, the radio wave can take a direct path and one or more reflected paths. The direct radio wave always arrives prior to the reflected waves. If the reflected waves are of sufficient amplitude, they will interfere with the direct wave. The relationship of the amplitude and time delay between the direct and reflected waves create peaks and nulls at the receiver, causing momentary signal fading or loss. In a digital system, this can result in very significant degradation, as the receiver loses signal acquisition and frame synchronization during each fade. The net effect is an increase in the residual bit error rate.
Media Platform Interface libraries. Part of Sun Microsystems' XTL Teleservices architecture. MPIs provide a layer of abstraction between details of the system services, applications and providers. The system services include a message passing "server", a data stream multiplexor streams driver, a provider configuration database and a database administration tool.

MPLS

MultiProtocol Label Switching. An IETF standard (RFC 2702) intended for Internet application, MPLS grew out of Cisco's proprietary TAG Switching protocol. MPLS is a widely supported method of speeding up IP-based data communication over ATM networks. As Frame Relay, IP and ATM come together, the concept is that of "route at the edge and switch in the core." In other words, routers are used at the ingress and egress edges of the network, where their high levels of intelligence can be best used and where their inherent slowness can be tolerated. Switches are used in the core of the network, where they can take advantage of the intelligent routing instructions provided by the routers, and where their inherent speed offers great advantage. MPLS takes this concept to new heights in an IP (Internet Protocol) WAN (Wide Area Network) such as the Internet, much as does Cisco's proprietary Tag Switching in the LAN (Local Area Network) domain. MPLS works like this: As an IP data stream enters the edge of the network, perhaps using Frame Relay access, the ingress Label Edge Router (LER) reads the full address of the first data packet and attaches a small "label" in the packet header, which precedes the packet. (The label comprises 20 bits of the MPLS header, which comprises 4 or 8 octets.) The Label Edge Switch Router (e.g., MPLS-capable ATM switches) in the core of the network examine the much-abbreviated label, and switch the packet with much greater speed than if they were forced to consult programmed routing tables associated with the full IP address. All subsequent packets in a data stream are automatically labeled in this fashion...and very quickly, as they have been anticipated. Further, the MPLS tag can be used to determine the most appropriate route, or Label Switched Path (LSP) for the data stream, in consideration of its nature and its explicit request for a differentiated Grade of Service (GoS). All packets that are forwarded in the same manner are known as a Forwarding Equivalence Class (FEC). MPLS integrates OSI Layer 2 (Data Link Layer) and Layer 3 (Network Layer), with the result being simplified and improved packet data exchange within a complex packet data network such as the Internet. Improvements in packet data exchange are achieved through path selection metrics including destination, available bandwidth, congestion, and error performance. MPLS has application in a wide variety of packet-based networks, including VoIP (Voice over Internet Protocol) and VPNs (Virtual Private Networks). See also ATM, IP and Tag Switching.

MPLS and Frame Relay Alliance

The MPLS Forum and Frame Relay Forum (FRF) merged in April 2003 to form the MPLS and Frame Relay Alliance. The organization initially comprised 60 member dedicated to advancing the recognition and acceptance of MPLS (MultiProtocol Label Switching) and frame relay, and promoting their inter- operability. The Frame Relay Forum was formed in May 1991 as an association of vendors, carriers and consultants committed to the education, promotion and implementation of frame relay in accordance with international standards. The FRF released 21 implementation agreements in its history. The MPLS Forum was established in 2000 to drive worldwide deployment of multi-vendor MPLS networks. See also Frame Relay and MPLS. www.frforum.com and www.mplsforum.org

MPM

Marketing Product Management.

MPN

Manufacturer's Part Number.

MPOA

MultiProtocol Over Asynchronous Transfer Mode. A developing set of architectural specifications defined by the ATM Forum. Working at Layer 3 (Network Layer) MPOA specifies standards for Layer 2 (Link Layer) switching through a Layer 3 router ” i.e., switched routing ” over an ATM fabric. MPOA allows companies to build scalable, enterprise-wide LAN internetworks that seamlessly interwork ATM with LAN protocols such as Ethernet, Token Ring, FDDI and Fast Ethernet. In effect, MPOA provides for inter-LAN cut- through, for the deployment of a WAN VLAN (Virtual Local Area Network) over an ATM backbone. MPOA accomplishes this by separating the route calculation function from the Network Layer forwarding function. In support of Network Layer packets such as IP and IPX, the edge routers will recognize the beginning of a data transfer and respond with an ATM network destination address. At that point, the router network will establish a cut- through SVC (Switched Virtual Circuit) which will eliminate router-by-router delays, thereby considerably increasing the speed of associated data transfer. This is accomplished by distributing the connection intelligence through the network to the edge devices; the traditional approach involves each router's acting independently on each packet in an effort coordinated by a centralized router, which can become overloaded. MPOA draws on existing standards, including the Layer 2 LANE (Local Area Network Emulation) from the ATM Forum, and the Layer 3 NHRP (Next Hop Resolution Protocol) from the IETF. MPOA also draws on IP extensions such as RSVP (Resource ReSerVation Protocol), which is used in support of isochronous data such as streaming video over IP networks. See the following four definitions. See also Classical IP over ATM, IP, LANE, NHRP, RSVP and VLAN.

MPOA Client

MPC. An ATM term. A protocol entity that implements the client side of the MPOA architecture. An MPOA client implements the Next Hop Client (NHC) functionality of the Next Hop Resolution Protocol (NHRP). See MPOA.

MPOA Server

MPS. An ATM term. A protocol entity that implements the server side of the MPOA architecture. An MPOA Server implements Next Hop Server (NHS) functionality of the NHRP. See MPOA.

MPOA Service Area

An ATM term. The collection of server functions and their clients. A collection of physical devices consisting of an MPOA server plus the set of clients served by that server. See the three definitions above and one below.

MPOA Target

An ATM term. A set of protocol address, path attributes, (e.g., internetwork layer QoS, other information derivable from received packet) describing the intended destination and its path attributes. See the four definitions immediately above.

MPOE

Minimum Point Of Entry, pronounced em-poe. Also known as MPOP (Minimum Point Of Presence), as defined by the FCC, and the LLDP (Local Loop Demarcation Point). The MPOE is the main point of physical and logical demarcation between the LEC (Local Exchange Carrier) and the customer premises. Up to the point of the MPOE, the telco is fully responsible for deployment and maintenance of the local loop connection. Beyond the MPOE, the user organization or building owner is responsible for the extension of the connection to the PBX, Centrex telephone sets, etc. In a campus environment comprising multiple buildings , there may be multiple points of demarcation, in which case one is designated by mutual agreement as the MPOE. Here's a working explanation from Ty Osborn, who works for the best CLEC in California (he says), tosborn@email.pacwest.com, "I was first introduced to MPOE when I had a (telco) tech out on prem (an apartment building) and could not find the DS-1 Bell had delivered earlier that day. He called and asked "where the heck is the MPOE?" (pronounced em-poe). In short, a MPOE might be a phone room with some punchdown blocks. An MPOE might be a box on the outside of the building. An MPOE is the last piece of equipment a phone company installs in a building for a customer it is providing service to. The MPOE is basically the phone company's last point of responsibility for that circuit. After that it's the customer's or the equipment or service company who is servicing the customer with on- premise equipment ” for example, a PBX.

MPOP

Minimum Point Of Presence. See MPOE.
Metropolitan Point Of Presence. The point of presence of a carrier within a metropolitan area. See also POP.

MPP

Massively Parallel Processing. A computer in which there are many processors and each has its own RAM (memory), which contains a copy of the operating system, a copy of the application code, and its own slice of the data, on which that processor works independently of the others.

MPPP

Multilink Point-to-Point Protocol. Also known as MP, MLP, and Multilink. A variant of PPP, MPPP is a method by which packet data traffic can be spread across multiple serial WAN (Wide Area Network) links in order to increase transmission speed. MPPP provides for packet fragmentation and reassembly, sequencing, and load balancing for both inbound and outbound traffic. MPPP can be configured for ISDN BRI and PRI channel aggregation (i.e., bonding), and both dialup modem and non-dialup asynchronous serial interfaces. See also Bonding and PPP.

MPRII

A Swedish PC monitor standard that specified a limit of 2.5 milligauss of ELF emissions when measured at about 20 inches from the screen.

MPS

Multi Page Signal. A frame sent in fax transmission if the sender has more pages to transmit.
Mobile Positioning Service. This technology uses the idle time of a GSM cellular system to figure where you (or more precisely, your cell phone) is. An alternative to GPS. Such MPS is designed for applications like emergencies, in which the cell phone can transmit to emergency authorities ” fire, police ” where the person in trouble actually is at that moment.

MPSK

Mobile switching centre .

MPTN

Multi Protocol Transport Networking. IBM scheme addressing multi protocol network support including TCP over SNA and SNA over IP.

MPU

Main Processor Unit.
Message Processor Unit.

MPTy

Multiparty. A wireless telecommunications term. A supplementary service provided under GSM (Global System for Mobile Communications).

MPX

Multiplex .

MQA

Multiple Queue Assignment. lets ACD system agents log into multiple queues.

MR

Modem Ready. An ASCII signal and visible "on" light that tells you that your modem is on and ready.
Modified Read. Relative element address differentiation code. A two-dimensional compression technique for fax machines that handles the data compression of the vertical line and that concentrates on space between the lines and within given characters. See MMR.

MRC

MF Receiver Card.
Monthly Recurring Charge.

MRFR

Master Reference Frequency Rack.

Mrm

An ATM term. An ABR service parameter that controls allocation of bandwidth between forward RM-cells, backward RM-cells, and data cells.

MRP

Materials Resource Planning. MRP and MRPII are computerized systems for planning the use of resources in manufacturing processes. Such resources include the scheduling of raw materials, production equipment, and processes. MRP now is known by the broader term Enterprise Resource Planning (ERP). See ERP for a full definition.

MRR

Monthly Recurring Revenue.

MRS

Menu Routing System.

MRSCC

MRS Central Controller.

MS

Mobile Station. A wireless telephone allowing mobility so that calls may be placed locally or in another geographic region. In short, another name for a cell phone.
Message Switch.
Microsoft.
Microprocessor System.

MS-DOS

MicroSoft Disk Operating System, now buried under Windows 95 and Windows 98, and fortunately eradicated from Windows NT and Windows 2000, making these operating systems far more reliable.

MS-SPRing

Multiplex- Section- Shared Protection Ring. See Self Restorable Rings.

MSA

Metropolitan Statistical Area. Sometimes known as SMSAs (Standard Metropolitan Statistical Areas) and MEAs (Metropolitan Economic Areas) and as defined by the U.S. Census Bureau, MSAs are geographic areas that contain cities of 50,000 or more population, and which include the surrounding counties. Such areas are characterized by the "community of interests." Using data from the 1980 census, the FCC allocated two cellular licenses to each of the 305 MSAs in the United States. The FCC developed LATA boundaries based largely on the SMSA concept.
Message Service Application.

MSAT

Mobile SATellite. Technology for transmitting and receiving satellite transmissions in moving vehicles.

MSAU

MultiStation Access Unit. See MAU.

MSB

Abbreviation for Most Significant Bit and Most Significant Byte. That portion of a number, address or field which occurs leftmost when its value is written as a single number in conventional hexadecimal or binary notation. The portion of the number having the most weight in a mathematical calculation using the value.

MSC

Mobile Switching Center. A switch providing services and coordination between mobile users in a network and external networks.
Malayasian Multimedia Super Corridor. The MSC is an ambitious development concept of the Malayasia government to develop an area of Malayasia with high-tech (telecom and computer) companies. The area is scheduled to house government offices, moving them out of traffic- congested Kuala Lumpur, the capital of the country. The government is installing a 4,300 kilometer fiber optic network in the MSC. If a company agrees to invest in the area, the Malayasian government extends tax breaks and other incentives. Overseeing the MSC is something called The Multimedia Development Corporation.
See Maintenance of Service Charge.

MSEngine

Mirrored Server Engine. The part of the Novell SFT III operating system that handles nonphysical processes, such as the NetWare file system, queue management, and the bindery. SFT III is split into two parts: the IOEngine (Input/Output Engine) and the MSEngine) and the MSEngine. The primary server and the secondary server each have a separate IOEngine, but they share the same MSEngine. The file system, receive buffers, and queue management system all reside in the MSEngine. Applications and NetWare Loadable Modules (NLMs) that do not address hardware directly can be mirrored by loading them in the MSEngine. If one server fails, applications and NLMs in the MSEngine continue to run. The MSEngine keeps track of active network processes; it provides uninterrupted network service when the primary server fails and the secondary server takes over. See IOEngine.

MSF

Mobile Serving Function.
Multiservice Switching Forum. A group devoted to open carrier standards especially those oriented to carrying all types of traffic, from voice to data, and focusing on using ATM as a primary switching and transport vehicle. The goal is also to support IP and frame relay services. www.msforum.org.

MSI

Modular Station Interface. A Dialogic board that interfaces analog phones to SCbus and PEB-based products.

MSISDN

Mobile Station ISDN number. An ISDN number provisioned to a mobile station subscriber and used to place a call.

MSIX

Metered Services Information Exchange. This protocol, first announced in June of 1997, provides a common interface for Internet applications to easily exchange detailed usage information with network billing and information systems. This specification includes a way for Internet Service Providers (ISPs) to effectively meter usage and charge for Internet services. Here are words from the June press release. Compaq and NetCentric announced a New Internet Metering Technology called MSIX, which is intended to accelerate the growth of new billable Internet services such as telephony, fax, video conferencing, content distribution and gaming. The commercial deployment of such applications has been hindered by the immaturity of the management and billing tools inside the Internet infrastructure. MSIX addresses many of these issues by providing a common mechanism to effectively meter application usage by a subscriber. It provides software developers and ISPs a common accounting framework that significantly simplifies network and billing integration. MSIX will make value-added services available to a much larger audience for the first time. MSIX complements other emerging protocols such as Reservation Protocol (RSVP) that allow network resources to be reserved and different quality-of-service levels to be offered. See www.compaq.com and www.netcentric.com.

MSL

Mirror Server Link. A dedicated, high-speed connection between Novell NetWare SFT III primary and secondary servers. The mirrored server link is essentially a bus extension from the primary to the secondary server. It requires similar boards in each server, directly connected by fiber-optic or other cables.

MSMQ

MicroSoft Message Queueing. MSMQ provides fault-tolerant support for distributed applications which work in conjunction with Message Transaction Server, MTS, which is a component manager for Windows NT, soon to be known as Windows 2000.

MSN

The Microsoft Network. Microsoft's version of American On Line (AOL). It has three main features. You can use it to access the Internet. You can send and receive email. You can use some of its own information services, none of which have impressed me sufficiently to use them. I use MSN as my primary email vendor because they do a good, reliable job with email and they have high-speed (56 Kbps) local phone numbers in all the domestic places in the United States I visit. They are weak overseas. IBM.Net is much better overseas.
Mobile Station Number. Also known as MIN (Mobile Identification Number) The telephone number of a cellular or PCS telephone. The unique MSN is paired with a unique ESN (Electronic Serial Number) for reasons of security. See also MIN and ESN.
Multi Subscriber Numbering. This British (UK) feature allows you to have two to ten numbers on your ISDN BRI line, which are distinguished to your ISPBX to handle individually. One could be a published fax number, one a personal direct number, one a priority customer number etc. If you have ISDN2 (British Telecom's obsolete BRI service), they must be contiguous but not necessarily if you have ISDN2e (Euro-ISDN BRI).

MSNF

Multisystem Networking Facility. An optional feature of certain IBM telecommunications access methods that allows more than one host running ACF/TCAM or VTAM to jointly control an ACF/NCP program.

MSO

Multiple System Operator. A company that operates more than one cable TV system.

MSP

See Mixed Signal Processor.
Metropolitan Service Provider. A MAN (Metropolitan Area Network) service provider. The term generally is applied to providers of GbE (Gigabit Ethernet) services.

MSS

Mobile Satellite System. MSSs are satellite systems which support mobile voice and/or data services. Constellations of such satellites are launched in various non- equatorial paths so that they whiz around the earth much like electrons whiz around the nucleus of an atom. As a result, one or more of the satellites always is in "view" of a small, low- power terminal. With orbital paths over all major land masses, one can conduct a cellular- like voice or data conversation from the jungles of New Guinea to another person in the Sahara desert.

MSRN

Mobile Station Roaming Number. This number is generated by the VLR (Visitors' Location Register) of the terminating MSC (Mobile Switching Center). A switch providing services and coordination between mobile users in a network and external networks. It contains the location area identification code of the called subscriber. this number is used by the MSC for the routing of the call. for call routing MSC sends the called MSISDN number to the HLR which sends the corresponding IMSI number to the VLR which in turn generates the MSRN number and route it back to the MSC via HLR (Home Location Register).

MSX

Mobile Switching eXchange. In a cellular environment, a MSX is akin to a central office (CO) in the wired world. More commonly, a MSX is known as a MSC (Mobile Switching Center) or a MTSO (Mobile Telephone Switching Office). See MTSO.

MT

An ATM term. Message Type: Message type is the field containing the bit flags of a RM-cell. These flags are as follows: DIR = 0 for forward RM-cells = 1 for backward; RM- cells BN = 1 for Non-Source Generated (BECN), RM-cells = 0 for Source Generated RM-cells CI = 1 to indicate congestion = 0 otherwise NI = 1 to indicate no additive increase allowed = 0 otherwise RA - Not used for ATM Forum ABR.

MT-RJ

An emerging de facto industry standard for optical fiber connectors used in premises networks, MT-RJ features a plug and jack technology, similar to that used in copper cabling and favored by the installers as more user-friendly than SC, ST and other fiber connectors. The MT-RJ connector is much smaller than predecessor fiber connectors, offering the advantage of increased port density. MT-RJ also is a drop-in replacement for RJ-45 copper-based cabling systems. The MT-RJ connector was defined through the cooperative efforts of AMP, Fujikura, and USConec, and comprises three primary components: the connector, the connector hardware and the transceiver. See also RJ, RJ-45, SC Connector, and ST Connector.

MTA

Message Transfer Agent. An OSI application process used to store and forward messages in the X.400 Message Handling System. Equivalent to Internet mail agent.
Apple Computer's Macintosh Telephony Architecture, now effectively dead.
Metropolitan Trading Area. An area defined by the FCC for the purpose of issuing licenses for PCS. Each MTA consists of several Basic Trading Areas (BTAs). The United States is broken down into 51 metropolitan trading areas for economic purposes. These boundaries were used for licensing PCS. The MTA was defined by the Federal Communications Commission's (FCC) revisions of the Rand McNally 1992 Commercial Atlas and Marketing Guide, based on certain economic and industrial criteria, in order to allocate areas of service. Each MTA is typically made up of several BTAs, and is named for the city that those BTAs would be most likely to use for means of commerce. There are presently 51 MTAs in the US.
Multimedia Terminal Adapter. See Multimedia Terminal Adapter and CMTS.

MTBF

Mean Time Between Failure. The length of time a user may reasonably expect a device or system to work before an incapacitating fault occurs. The MBTF statistical method was developed and administered by the U.S. military for purposes of estimating maintenance levels required by various devices. Since accurate statistics (i.e. lots of numbers) require a basis of "failures per million hours of operation," an MTBF estimate on a single device is not statistically very accurate. It would take over 100 years to see if the device really had that many failures. Similarly, since the MTBF is an estimate of averages, half of the devices can be expected to fail before then, and half after. Thus, MTBF cannot be used as a guarantee of how long something might or might not work for. Telecommunications systems operate on the principle of "availability," for which there is a body of CCITT Recommendations. See Availability.

MTC

Mobile Terminating Call. Mobile phone receiving the inbound leg of a call. See also MTO.

MTD

Memory Technology Drive.

MTIE

Maximum Time Interval Error.

MTM

Maintenance Trunk Monitor.
Mean Time Maintenance.

MTNM Version 3

Multi-Technology Network Management. On October 28, 2003, The TeleManagement Forum announced the release of the Multi Technology Network Management (MTNM) Version 3. About 40 of the world's top telecommunications software vendors and network equipment suppliers have incorporated the MTNM interface into their products, making it a de facto industry standard for network management of optical technologies. Version 3 eases the integration of multi-vendor products in an operator's network, and features a host of enhancements to support new and existing technologies, such as ATM, frame relay, SONET/SDH, DSL and Ethernet. New features in MTNM Version 3, according to the Forum, include:

Support for new transport technologies such as Digital Subscriber Line (DSL), microwave radio, and management of Ethernet tributary interfaces
Enhanced support for existing technologies such as ATM and DWDM and generalization of Multiplex Section Protection (MSP)
Enhancements not specific to transport such as connection, configuration, equipment, performance and fault management. The Forum likely will submit MTNM version 3 to the ITU (International Telecommunications Union) for acceptance as a standard.

MTP

Message Transfer Part of the SS7 Protocol. It provides functions for basic routing of signaling messages between signaling points. It is Level 1 through 3 protocols of the SS7 protocol stack. MTP 3 (Level 3) is used to support BISUP.

MTS

Message Telecommunications Service. AT&T's name for standard switched telephone service. Also called DDD, for Direct Distance Dial.
Member of the Technical Staff. A common term at AT&T Bell Labs, Bellcore and other R&D labs.
Microsoft Terminal Server. Microsoft's answer to a dumb terminal.
Measured Toll Service.
Material Transfer System.

MTSO

Mobile Telephone Switching Office. This central office houses the field monitoring and relay stations for switching calls between the cellular and wire-based (land-line) central office. The MTSO controls the entire operation of a cellular system. It is a sophisticated computer that monitors all cellular calls, keeps track of the location of all cellular- equipped vehicles traveling in the system, arranges handoffs, keeps track of billing information, etc.

MTTR

Mean Time to Repair. The average time required to return a failed device or system to service.

MTU

Maximum Transmission Unit. The largest possible unit of data that can be sent on a given physical medium. Example: The MTU of Ethernet is 1500 bytes.
Multi Tenant Unit or Multiple Tenant Unit. A fancy name for a building or group of buildings that house many tenants ” businesses and perhaps also residences. Such MTU could be an office building, office park or corporate campus, medical facility, hotel or college dormitory. The reason for this term is that the new newer carriers (such as the CLECs) or the building's owner talk about providing telecom service to the tenants. They talk about placing a DSL access router (also called a DSLAM) into the basement of a MTU and give themselves access to the building's existing copper wiring (the copper was installed when the building was built and/or renovated to support telephone lines). DSL allows high-speed data transmission (typically for access to the Internet) over that existing wiring to and from all customers inside the MTU. According to a recent study on MTUs, MTU owners deploy broadband in order to attract and retain tenants and add new revenue streams. A new class of broadband provider is moving the Internet access point of presence, or POP, into the actual buildings where tenants reside. These Mini-POPs use scaled-down versions of aggregators used in telecommunication's companies central offices, or even enterprise office switches, allowing tenants to share the cost of an expensive T-1 or other broadband Internet link. Most MTU broadband providers are offering, or looking to offer, value-added services such as voice, video, and application services as a way for customers to build new revenue streams. Many also offer remote and on-site network management, as well as cable installation services.

MU

Monitoring Unit. A wireless telecommunications term. Devices added to circuit configurations that use sophisticated trending rules with fault and topology information to determine potential outages.

Mu Law

The PCM voice coding and companding standard used in Japan and North America. A PCM encoding algorithm where the analog voice signal is sampled eight thousand times per second, with each sample being represented by an eight bit value, thus yielding a raw 64 Kbps transmission rate. A sample consists of a sign bit, a three bit segment specifying a logarithmic range, and a four bit step offset into the range. All bits of the sample are inverted before transmission. See A Law and PCM.

MUA

An acronym for Mail User Agent, is the end user's mail program, like Eudora.

MUD

Multi-User Dungeons. A term that Time Magazine in its 9/13/1993 issue called "the latest twist in the already somewhat twisted world of computer communications." Time called it "a sort of poor man's virtual reality" ” created by using words, not expensive head-mounted displays. The first MUD apparently was invented in 1979 as a way for British university students to play the fantasy game Dungeons & Dragons by networked computers. MUD are basically now online games environments that use a great deal of network bandwidth.
Multi-User Dimension. This term refers to users who connect to each other via a host computer.
In the mud means low volume.

Mudbox

An unsheltered item of equipment that is sufficiently rugged to withstand adverse environments. It is expected to work perfectly though it sits outdoors in good and bad weather.

MUDS

Multi-User Dungeons. A cyberspace term. MUDS are elaborate fictional gathering places that users create one room at a time. All these "spaces" have one thing in common, according to cyberspace wisdom, they are egalitarian. Anybody can enter the rooms (provided he has the correct equipment) and everybody is afforded the same level of respect. A significant feature of most MUDs is that users can create interactive objects that remain in the program after they leave. MUD worlds can be built gradually and collectively. See also USENET.

MULDEM

A contraction for Multiplexer Demultiplexer, referring to a piece of equipment which performs both functions and generally operates between two of the AT&T digital hierarchy rates (i.e., DSI to DS3).

Mule Tape

Mule tape is very strong, flat tape which is used to pull cable through underground conduit. Here's how it typically works: First, you use a bore to make an underground hole. Then you fill that hole with hollow concrete cement pipes joined together to form one long underground conduit (i.e. tunnel). Then you go to one end of the tunnel and use a air compressed device to blow a very lightweight "birdie" attached to a lightweight string through the tunnel. Someone at the other end catches the birdie and pulls gently on the string. Attached to the end of the string is strong mule tape. He keeps pulling on it. Attached to the end of the mule tape is the telecommunications cable ” fiber or wire ” that you really want to instal in the underground conduit. The whole point of this elaborate procedure is that it's far better for the cable to lay it after the pipes are laid than it is during the installation process when the cable could be damaged.

Multi-Modal Browsing

An interface architecture where users interact with a system by using a variety of input/output mechanisms such as voice capabilities, touch screens, video and graphics.

Multi Mode Fiber

See MMF.

Multi Vendor Integration Protocol

See MVIP.

Multi Wavelength Optical Repeater

See MOR.

Multi-

In this dictionary, I sometimes include a dash between words beginning with "multi" and ending with something else. Sometimes I don't. I try to follow the typical terminology conventions used in the industry, although conventions don't always exist. If you don't find the word spelled with a hyphen, look for it without a hyphen.

Multi-Access

The ability of several users to communicate with a computer at the same time with each working independently on their own job.

Multi-Address Calling Facility

A system service feature that permits a user to nominate more than one addressee for the same data. The network may accomplish this sequentially or simultaneously .

Multi-Alternating Routing

Alternate routing with provision for advancing a call to more than one alternate route, each of which is tested in sequence in the process of seeking an idle path.

Multi-Carrier Modulation

MCM. A technique of transmitting data by dividing the data into several interleaved bit streams and using these to modulate several carriers. MCM is a form of frequency division multiplexing.

Multi-Cast

Also spelled multicast. The broadcast of messages to a selected group of workstations on a LAN, WAN or the Internet. Multicast is communication between a single device and multiple members of a device group. For example, an IPv6 router might address a series of packets associated with a routing table update to a number of other routers in a LAN internetwork. Similarly, a LAN-attached workstation might address a transmission to a number of other LAN-attached devices. Companies are discovering they can distribute material to large numbers of employees and others on their intranets more efficiently using multicast than they can by sending such material in separate bursts to each user. In multicast mode, routers distribute a given file to all hosts that have signaled they want to receive the material, using the Class D addresses of the IP addressing hierarchy. See also Multicast and Multi-Cast Packets and IPV6. Contrast with Unicast, Anycast and Broadcast.

Multi-Cast Packets

Multi-cast packets are addressed to multiple devices within a group of devices. For example, LAN stations use multi-cast packets to deliver information to a specific set of devices such as routers, file servers, and hosts. See Multi-Cast.

Multi-Cast User Message

A user message generated at the source node and distributed to two or more destination nodes.

Multi-Casting

The ability of one network node to send identical data to a number of end points - known as broadcast in other circles; one example is if new software or addressing updates need to be distributed to all users; also, a point-to-multipoint video transmission is a multi-cast operation.

Multi-Channel

The use of a common channel to make two or more channels either by splitting the frequency band of the common channel into several narrower bands (called frequency division multiplexing) or by allocating time slots in the entire channel (time division multiplexing).

Multi-Channel Aggregation

A feature under some versions of Windows which gives remote users the option of using two phone lines for the same remote session. This way you double bandwidth, thus making their session go twice as fast. I've never used this feature and I'm doubtful that it works as advertised.

Multi-Channel Microwave Distribution Service

MMDS. An FCC name for a service (operating in the frequency range 2150-2162 MHz and 2500-2686 MHz) where multiple NTSC video channels are broadcast within a limited geographic area (typically 25 mile radius from single omnidirectional antenna). Also called multi-channel multipoint distribution service or "wireless cable" service.

Multi-Channel Multipoint Distribution Service

MMDS. An FCC name for a service (operating in the frequency range 2150-2162 MHz and 2500-2686 MHz) where multiple NTSC video channels are broadcast within a limited geographic area (typically 25 mile radius from single omnidirectional antenna). Also called multi-channel microwave distribution service or "wireless cable" service.

Multi-Channel Transmitter

A transmitter using low level combining techniques to process many channels at the same time.

Multi-Conductor

More than one conductor within a single cable complex.

Multi-Domain Network

In IBM Systems Network Architecture technology, a network that contains more than one host based System Services Control Point (SSCP).

Multi-Drop Line

A multi-drop private line or data line is a communications path between two or more locations requiring two or more LECs, but there are multiple 'drops' per LEC. For example, a hospital in Detroit has a data line going to NY, NY. But in New York, NY there are four hospitals in a several block area. Therefore, one data line with four drops . Then you can have a multipoint - multidrop line, which is a combination of both.

Multi-Drop Line

A communications channel that services many data terminals at different geographical locations and in which a computer (node) controls utilization of the channel by polling one distant terminal after another and asking it, in effect, "Do you have anything for me?"

Multi-Fiber

A fiber that supports propagation of more than one of a given wavelength. See Multi-Mode.

Multi-Frame

In PCM systems, a set of consecutive frames in which the position of each frame can be identified by reference to a multi-frame alignment signal. The multi- frame alignment signal does not necessarily occur, in whole or in part, in each multi-frame.

Multi-Frequency Monitors

Also known as multisync or multiscan monitors. They can show images in several resolution standards. Such versatility makes them more expensive than single-resolution monitors (e.g. a standard VGA) but also less prone to instant obsolescence. A multisync monitor showing a VGA may or may not look better than VGA monitor showing a VGA image. That depends on the screen's other attributes.

Multi-Frequency Pulsing

An in-band address signaling method in which ten decimal digits (the numbers on the touchtone pad) and five auxiliary signals are each represented by selecting two frequencies and combining them into one "musical" sound.. The frequencies are selected from six separate frequencies ” 700, 900, 1100, 1300, 1500 and 1700 Hz. See also Captain Crunch.

Multi-Frequency Signaling

MF. A signaling code ( utilizing pairs of frequencies in the 700-1700 Hz range) for communications between network switches. Code includes 10 digits and special auxiliary signals.

Multi-Function Card

A PC card that incorporates multiple peripherals such as a network adapter and modem.

Multi-Function Peripherals

MFS. These are devices which take on two or more functions generally associated with individual peripherals and combine these into one product or in a linker series of modules. A multi-function peripheral might combine a fax machine with a photocopier with a computer printer with a scanner. The term is not very precise, but it tends increasingly to mean a computer device that will print, photocopy, fax and/or scan.

Multi- Homed

Multihomed means connected to multiple networks simultaneously for redundancy and to handle load. All major telecommunications carriers are multihomed with connections to several other carriers at all major interconnection points on their networks. A multi-homed host is a computer connected to more than one physical datalink. The data links may or may not be attached to the same network.

Multi-Hop

An example of a single hop system is a microwave system between one building (let's say downtown San Francisco) and another across town (let's say uptown San Francisco). Each with one microwave antenna on its roof. Let's say we wanted to extend that system to Oakland. We'd put a second antenna on the uptown San Francisco building and shoot across to an antenna in Oakland. That building would now have a multi- hop transmission system.

Multi-Hosting

The ability of a Web server to support more than one Internet address and more than one home page on a single server. Also called Multi-Homing.

Multi-Leaving

In communications, the transmission (usually via bisync facilities and using bisync protocols) of a variable number of data streams between user devices and a computer.

Multi-Level Precedence Preemption

MLPP. A system in which selected customers may exercise preemption capabilities to seize facilities being used for calls with lower precedence levels.

Multi-Line Hunt

The ability of switching equipment to connect calls to another phone in the group when other numbers in the group are busy.

Multi-Line Telephone

Any telephone set with buttons which can answer or originate calls on one or more central office lines or trunks. Originally all multi-line telephones were 1A2 and they came in sizes of 2, 3, 5, 9, 11, 17, 19, 29, and 60 lines. Now, skinny wire electronic key systems come in all sizes. See Key Telephone System.

Multi-Line Terminating System

Premises switching equipment and key telephone type systems which are capable of terminating more than one local exchange service line, WATS access line, FX circuit, etc.

Multi-Link

Multiple links. Several services can make use of multiple links in order to increase bandwidth. Examples include Multilink Frame Relay and Multilink PPP. Multilink Frame Relay is used to combine together multiple T-1s (usually two-four) in order to provide access to a Frame Relay network at speeds greater than the 1.544 Mbps provided by T-1. The alternative would be Fractional T-3, which generally is not available. Multilink Frame Relay uses an inverse multiplexing process to spread a high-speed Frame Relay data stream across multiple T-1s, recombining the original data stream at the edge of the Frame Relay network. Multilink PPP commonly makes use of two ISDN B (Bearer) channels, each at 64 Kbps, to increase Internet access speed to 128 Kbps. Multilink PPP requires that the two B channels be bonded together, in order that the data stream be multiplexed and switched as a single entity.

Multi-Link PPP

See MPPP.

Multi-Link Procedure

A procedure (defined in ITU-T Recommendations X.25 and X.75) that permits multiple links connecting a single pair of nodes to provide service to the network layer on a shared basis. Such sharing provides greater effective throughput capacity and availability than a single link.

Multi-Location Billing

Multilocation Billing is an option whereby a long distance carrier bills separate locations and applies volume discounts pro-rated to each site based on usage, or fixed percentage with pro-rated discounts to sites based on usage.

Multi-Location Extension Dialing

An AIN (Advanced Intelligent Network) service providing network-based dialing between multiple company locations on the basis of an abbreviated dialing plan. Working much like coordinated dialing plans in the PBX world, the user need only dial an access code (e.g., "7") and a 4-digit extension number. The network connects the call to the target extension at the correct location.

Multi-Longitudinal Mode Laser

An injection laser diode which has a number of longitudinal modes.

Multi-Master

An inherent mode of the VME bus which allows the controlled sharing of the bus by multiple CPUs under a flexible priority structure.

Multi-Media

Usually spelled multimedia these days. Multimedia is the combination of multiple forms of media in the communication of information. Multimedia enables people to communicate using integrated media: audio, video, text, graphics, fax, and telephony. The benefit is more powerful communication. The combination of several media often provides richer, more effective communication of information or ideas than a single media such as traditional text-based communication can accomplish. Multi-media communication formats vary, but they usually include voice communications ( vocoding , speech recognition, speaker verification and text-to-speech), audio processing (music synthesis, CD-ROMs), data communications, image processing and telecommunications using LANs, MANs and WANs in ISDN and POTS networks. Multimedia technology will ultimately take the disparate technologies of the computer, the telephone, the fax machine, the CD player, and the video camera and combine them into one powerful communication center. Technologies that were once analog ” video, audio, telephony ” are now digital. The power of multimedia is the integration of these digital technologies. To many people, "multimedia" (as defined above) is a disparate collection of technologies in search of a purpose. And it's true: most of the merger of media (as above) is taking place in business communications in the moving around of compound documents. Meantime, multimedia has moved into training and in the home for education and entertainment. See Authoring, Compound Documents, Hypermedia, Ole, Shared Screens, Shared Whiteboards and Synchronization.

Multi-Media Capabilities

The ability to run simultaneous voice, image, data and video applications on a computer. A technology that requires enormous bandwidth and processing power. See Multi-Media.

Multi-Media Network

A network capable of carrying multiple forms of user information such as voice text, sounds, etc.

Multi-Media PC

The Multimedia PC Council now defines a multimedia PC as a PC having a minimum of two megabytes of memory, a 30 megabyte hard drive, a CD ROM drive, digital sound support and Microsoft's Multimedia Extensions for Windows. See Multi-Media.

Multi-Media Protocol

A protocol suitable for handling multiple forms of information such as voice, text, pictures, numbers, etc.

Multi-Mode

In fiber-optics, an optical fiber designed to allow light to carry multiple carrier signals distinguished by frequency or phase at the same time (contrasts with single- mode). (Also spelled multimode .)

Multi-Mode Distortion

In an optical fiber, a result of different values of the group delay for each individual mode at a single wavelength. It isn't the same as "multi- mode dispersion."

Multi-Mode Dispersion

Dispersion fattens or smears the transmitted signal, making it difficult to identify the original information sent. Dispersion limits the amount of information that can be transmitted. Dispersion is much worse on the information carried on multi-mode fibers, because there's simple more going on. As a result, dispersion limits the rate and how you can send the information. Single mode is the preferred mode for long distance.

Multi-Mode Fiber

See MMF.

Multi-NAM

A cellular telephone term to allow a cellular phone to have two (or more) phone numbers, each of which can be on a different cellular system. This lets you get service from many cellular phone companies. For example, you could subscribe to one carrier in your home city and another in a distant city ” perhaps one you travel to often. Once upon a time this saved you paying high roaming charges. But new cell phone prices make multi-NAM an anachronism.

Multi-Path

Multiple routes taken by RF energy between the transmitter and the receiver. Signal can cancel or reinforce . Varying multipath (at sunset or sunrise ) causes varying signal strength that sounds like a train's steam engine starting up.

Multi-Path Error

Errors caused by the interference of a signal that has reached the receiver antenna by two or more different paths. Usually caused by one path being bounced or reflected.

Multi-Plex

See Multiplex.

Multi-Point

A configuration or topology, designed to transmit data between a central site and a number of remote terminals on the same circuit. Individual terminals will generally be able to transmit to the central site but not to each other.

Multi-Point Circuit

A circuit connecting three or more locations. It is often called a multidrop circuit. See also Multi-Point and Multi-Drop Line.

Multi-Point Distribution Service

A one-way domestic public radio service rendered on microwave frequencies from a fixed station transmitting (usually in an omnidirectional pattern) to multiple receiving facilities located at fixed points.

Multi-Point Grounding System

A system of equipment bonded together and also bonded to the facility ground at the nearest location of the facility ground.

Multi-Point Private Line

A multi-point private line or data line is a communications path between two or more locations requiring two or more LECs. For example.... A location in Detroit, MI has a data line going to NY, NY, then down to Washington, DC. See also Multi-drop private line.
A single communications link for two or more devices shared by one computer and or more computers or terminals. Use of this line requires a polling mechanism. It is also called a multidrop line.

Multi-Processing

A type of computing characterized by systems that use more than one CPU to execute applications. Multi-processing is not multi-tasking, which is the ability to have more one application running on a system at the same time. The technique is not associated with multi-processing, nor does it require multi processing to take place. Multi-tasking typically uses a computer with one CPU (e.g. your desktop or laptop). Multiprocessing uses a computer with several CPUs, often a server. See Multi-Tasking.

Multi-Processor Kernel

Software that enables a computer operating system to use more than one CPU chip simultaneously. Such software is typically used on servers. It is used to speed up a server.

Multi-Programming

Computer system operation whereby a number of independent jobs are processed together.

Multi-Protocol Message Routers

A device which converts different electronic mail formats. Such a router would be used to move electronic mail from a cc mail equipped-LAN to a Davinci e-mail LAN to a Wang mini-computer based system.

Multi-Protocol Message Routers

Multi-Purpose Internet Mail Extension

See MIME.

Multi-Rate ISDN

"Nx64" or switched-fractional T-1 lets users combine multiple ISDN PRI "B" channels on a call-by-call basis. Since each "B" channel operates at 64 kbps, users could get from 128 kbps to 1.544 Mbps of bandwidth in 64 kbps increments.

Multi-Server Network

A single local area network (one cabling system) that has two or more file servers attached. Network addresses assigned to the LAN drivers are the same in each file server because the network boards are attached to the same cabling system. On a multi-server network, users can access files from any file server to which they are attached (if they have access rights). A multi-server network should not be confused with an inter network (two or more networks linked together through an internal or external router).

Multi-Session

When pictures are placed on Kodak Photo CDs the first time, that's called the first session. And the result is a single session CD. The next time more photos are put on the disk, the disk is now called a multi-session Photo CD. To read such a disk, you need a CD-ROM player, which is specifically called a multi-session CD-ROM player.

Multi-Stage Dialing

The device needs to break the dialing sequence up into a number of stages in order to execute and complete the call. This is referred to as "multi- stage" or "incremental" dialing. This type of dialing is needed in cases where the switching domain prompts the device for more digits (by sending dial tone again or some other tone).

Multi-Stage Queuing

This a term typically used in Automatic Call Distributors . It is the ability to array a number of agent groups in a routing table. The notion of multiple agent groups being addressed may mean that the system may be able to "look-back" and "look forward" as it searches for a free agent in the right group to take the call presently holding.

Multi-Station

Any network of stations capable of communicating with each other on one circuit or through a switching center.

Multi-Tasking

The concurrent management of two or more distinct tasks by a computer. Although a computer with a single processing unit (as virtually all PCs are) can only execute one application's code at a given moment, a multi tasking operating system can load and manage the execution of multiple applications, allocating processing cycles to each in sequence. Because of the processing speed of computers, the apparent result is the simultaneous processing of multiple tasks. Standard mode Windows performs multi tasking only in the form of context switching. 386 enhanced mode allows multi tasking in the form of time slicing. See Multi-Processing.

Multi-Tenant Sharing

The capability of a PBX to serve more than one tenant in a building. This process is a new option for building owners. They now become the Telephone Company for tenants in the building. There is money in this business, but chiefly on the resale of long distance phone calls.

Multi-Tester

Usually an alternate name for VOLT-OHM-MILLIMETER, but may also apply to other MULTI-FUNCTION testing devices.

Multi-Threading

See Thread.

Multi-Tier Tariffs

A way of paying for something (i.e. equipment) from your local phone company. The idea is that one tier of your monthly payments is to pay off the equipment, and after a finite period, this tier payment drops to zero. The next tier is to pay for your monthly service and it is ongoing. Other tiers are for other reasons. As this technique was practiced by the Bell System, it was called "two tier." You will no longer find two tier tariffs in common use.

Multi-User PC

A microcomputer that has several terminals attached to it, so that multiple users can simultaneously use its resources. Multi-user PCs can either slice up the time of a single microprocessor or can give each terminal-based user his own microprocessor. Multi-user PCs are an alternative to LANs and are typically used in specialized, one- application solutions, such as a doctor's office billing system.

Multi-User Software

An application designed for simultaneous access by two or more network nodes, i.e. two or more users on a network. It typically employs file and/or record locking. It is not associated with multi processing, nor does it require multi processing to implement.

Multi-User Telecommunications Outlet Assembly

A grouping in one location of several telecommunications outlets/connectors.

Multi-Vendor Integration Protocol

See MVIP.

Multi-Wavelength Optical Repeater

See MOR.

Multi-Way Communication

A multimedia definition. Multi-way communication goes between two people, or between groups of people in all directions. Multi-way communication can be in real-time, or in store-and-forward mode. Examples of multi-way communication include a video conference, where one individual is giving a presentation to a group of people who listen and ask questions from their workstations; and group conferencing, where several people collaborate, supported by audio, video, and graphics on their workstation screens.

Multicast

Also spelled multi-cast. Multicast allows messages to be sent to a selected group of workstations on a LAN, WAN or the Internet. Multicast is communication between a single device and multiple members of a device group. For example, an IPv6 router might address a series of packets associated with a routing table update to a number of other routers in a LAN internetwork. Similarly, a LAN-attached workstation might address a transmission to a number of other LAN-attached devices. Companies are discovering they can distribute material to large numbers of employees and others on their intranets more efficiently using multicast than they can by sending such material in separate bursts to each user. In multicast mode, routers distribute a given file to all hosts that have signaled they want to receive the material, using the Class D addresses of the IP addressing hierarchy. The message is sent from the transmitter down the tree only to those nodes that need to receive it in order to further distribute it to downstream nodes, from those nodes only to those that need to receive it in order to further distribute it to downstream nodes, and so on. At each of those points, the message is replicated and retransmitted only as necessary. Multicasting is much more efficient in many applications than is either broadcasting or unicasting . See also Multicast and Multi-Cast Packets and IPV6. Contrast with Unicast, Anycast and Broadcast.
A TV term that simply means more channels will be available for viewers . It's often used to refer to the explosion of special interest channels that will be around when digital TV hits the scene and uses the CATV network to transmit its programs. I suspect that the explosion of channels will lend new meaning to Johnny Carson quips about channels for "one-eyed, one-legged transvestites."

Multicast Address Resolution Server

See MARS.

Multicast Backbone

Mbone. A method of transmitting digital video over the Internet in real time. The TCP/IP protocols used for Internet transmissions are unsuitable for real-time audio or video; they were designed to deliver text and other files reliably, but with some delay. MBONE requires the creation of another backbone service with special hardware and software to accommodate video and audio transmissions; the existing Internet hardware cannot manage time-critical transmissions.

Multichannel Transmitter

A transmitter using low level combining techniques to process many channels at the same time.

Multichannel

The use of a common channel to make two or more channels.

Frequency Division Multiplexing (FDM) accomplishes this by splitting the frequency band of the common channel into several narrower bands. Time Division Multiplexing (TDM) divides the entire channel into time slots.

Multichannel Aggregation

A feature under Windows NT which gives remote users the option of using two phone lines for the same remote session. This way you double bandwidth, thus making their session go twice as fast.

Multichannel Audio Digital Interface

See MADI.

Multichannel Transmitter

A transmitter using low-level combining techniques to process many channels at the same time.

MULTICS

MULTiplexed Information and Computing System. In the mid-1960's, MULTICS was the focus of a huge development effort sponsored by MIT (Massachusetts Institute of Technology), Bell Telephone Laboratories and General Electric. The idea was to develop a "computer utility" that would provide computing resources to the population of an entire city or area ” in contemporary terms, we would describe this as a multi-user time-share system. MULTICS was a failure. When Bell Labs pulled out of the project, Ken Thompson, Dennis Ritchie and a few other Bell Labs programmers developed UNICS, a single-user variant of MULTICS. UNICs later became known as UNIX. See UNIX.

Multidrop

Also known as a point-to-multipoint circuit, a multidrop circuit has one point of termination on one end, and multiple points of termination on the other end. For example, a hospital in Detroit leases a private data circuit going to NYC (New York City) to connect the Detroit primary data center with the smaller host computers in each of four NYC hospitals. Therefore, the "head end" in Detroit connects to NYC, where there are four drops. See also Drop.

Multifiber Cable

A fiber-optic cable having two or more fibers, each of which can be an independent optical transmission channel.

Multiframe

In PCM systems, a set of consecutive frames in which the position of each frame can be identified by reference to a multiframe alignment signal. The multiframe alignment signal does not necessarily occur, in whole or in part, in each multiframe.

Multifrequency Monitors

Also known as multisync or multiscan monitors. They can show images in several resolution standards. Such versatility makes them more expensive than single-resolution monitors (e.g., a standard VGA) but also less prone to instant obsolescence. A multisync monitor showing a VGA may or may not look better than VGA monitor showing a VGA image. That depends on the screen's other attributes.

Multifrequency Pulsing

More commonly known as Dual Tone Multifrequency (DTMF). See DTMF.

Multifrequency Signaling

More commonly known as Dual Tone Multifrequency (DTMF). See DTMF.

Multifunction Peripherals

Multihomed Computer

Any computer system that contains multiple network interface cards and is attached to several physically separate networks; also know as a multihomed host. The term can also be applied to a computer configured with multiple IP addresses for a single network interface card.

Multihomed Host

A host which has a connection to more than one physical network. The host may send and receive data over any of the links but will not route traffic for other nodes. See also host; router.

Multihoming

The practice of linking to multiple-access ISPs over physically discrete lines to the Internet. This is done to combat downtime caused by a malfunction of one particular line.

Multilevel Precedence Preemption

MLPP. A system in which selected customers may exercise preemption capabilities to seize facilities being used for calls with lower precedence levels.

Multilink

See Multi-link.

Multiline Hunt

The ability of switching equipment to connect calls to another phone in the group when other numbers in the group are busy.

Multiline Telephone

Any telephone set with buttons which can answer or originate calls on one or more central office lines or trunks. Originally all multiline telephones were 1A2 and they came in sizes of 2, 3, 5, 9, 11, 17, 19, 29, and 60 lines. Now, skinny wire electronic key systems come in all sizes. See Key Telephone System.

Multiline Terminating System

Premises switching equipment and key telephone type systems which are capable of terminating more than one local exchange service line, WATS access line, FX circuit, etc.

Multimedia

See Multi-Media.

Multimedia ACD

Also called multimedia queueing. Automated Contact Distribution system that is enabled to process multiple media types, such as voice calls, e- mails , incoming fax documents, web chat requests and Internet voice/video interactions using queuing/hold strategies. For example, a sales queue could be configured and staffed by sales associates that could evenly distribute all sorts of incoming customer sales requests (fax, phone calls, emails, etc.) to sales associates by blending computer and phone capabilities into a common sales response system. This makes sales associates more efficient and also provides a more consistent service level to all customers. See also Multimedia Queuing.

Multimedia Communications Forum

See MMCF.

Multimedia Extensions

See MMX.

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. See MMS.

Multimedia Mobile Access Communication

See MMAC.

Multimedia Queuing

The term was originally invented by Interactive Intelligence of Indianapolis, who makes a communications server ” a telephone and messaging system based in a PC. The idea is that the communications server should do way more than servicing mere phone calls. It should handle all media streams ” email, fax mail, chats, etc. ” with the same discipline as phone systems (particularly automatic call distributors) handle plain ordinary phone calls. All "calls" of whatever media should be treated by the system as of equal importance. See also Multimedia ACD.

Multimedia Super Corridor

The MSC is an ambitious development concept of the Malayasia government to develop an area of Malayasia with high-tech (telecom and computer) companies. The area is scheduled to house government offices, moving them out of traffic-congested Kuala Lumpur, the capital of the country. The government is installing a 4,300 kilometer fiber optic network in the MSC. If a company agrees to invest in the area, the Malayasian government extends tax breaks and other incentives. Overseeing the MSC is something called The Multimedia Development Corporation.

Multimode

See Multi-Mode above.

Multimode Dispersion

Dispersion fattens or smears the transmitted signal, making it difficult to identify the original information sent. Dispersion limits the amount of information that can be transmitted. Dispersion is much worse on the information carried on multimode fibers, because there's simple more going on. As a result, dispersion limits the rate and how you can send the information. Single mode is the preferred mode for long distance.

Multimode Distortion

Multimode fiber allows many modes of light to propagate down the fiber-optic path. Multimode fibers are generally used for short-distance data links, as they provide limited bandwidth due to modal dispersion. The relatively large core of a multimode fiber allows good coupling from inexpensive LEDs, and the use of inexpensive couplers and connectors. Multi-mode fiber typically has a core diameter of 25 to 200 microns. The core is much larger than single-mode fiber and allows several modes of light to be passed through it. Multimode fiber was the original medium specified for FDDI. See also Single Mode Fiber.

Multimode Fiber

A fiber-optic cable with a wide core that provides multiple routes for light waves to travel. Its wider diameter of between 25 to 200 microns prevents multimode fiber from carrying signals as far as single-mode fiber due to modal dispersion.

Multiparty Line

A single telephone line which serves two or more subscribers (net- work access lines). The term usually means either a "two party" or a "four party" line. Lines serving more than four parties are called "rural lines".

Multipath

Multiple routes taken by RF energy between the transmitter and the receiver. Signal can cancel or reinforce. Varying multipath (at sunset or sunrise) causes varying signal strength that sounds like a train's steam engine starting up.

Multipath Error

Errors caused by the interference of a signal that has reached the receiver antenna by two or more different paths. Usually caused by one path being bounced or reflected.

Multipath Fading

The signal degradation in a cellular radio system that occurs when multiple copies of the same radio signal arrive at the receiver through different reflected paths. The interference of these signals, each having traveled a different distance, result in phase and amplitude variations. The radio signal processing in both the base station and mobile units have to be designed to tolerate a certain level of multipath fading. See Rayleigh Fading for a longer explanation.

Multipoint

Multipoint Circuit

A circuit connecting three or more locations. It is often called a multidrop circuit. See also Multipoint and Multidrop Line.

Multipoint Grounding System

A system of equipment bonded together and also bonded to the facility ground at the nearest location of the facility ground.

Multipoint Private Line

See Multidrop Line.

MultiPulse-Maximum Likelihood Quantization

See MP-MLQ.

Multiplayer Gaming

See Telegaming.

Multiple Access

The ability of several personal computers connected to a Local Area Network to access one another through a common addressing scheme and protocol.

Multiple Aaccess Schemes

Methods of increasing the amount of data that can be transmitted wirelessly within the same frequency spectrum. RFID readers use Time Division Multiple Access, or TDMA, meaning they read tags at different times to avoid interfering with one another.

Multiple Address Message

A message to be delivered to more than one destination.

Multiple Address Systems

MAS. A microwave point-to-multipoint communications system, either one-way or two-way, serving a minimum of four remote stations. The private radio MAS channels are not suitable for providing a communications service to a larger sector of the general public, such as channels the commission has allocated for cellular paging or specialized mobile radio services. (SMR).

Multiple Console Operation

A phone system with this feature can use more than one attendant console. It's good to know the maximum number of consoles your chosen PBX can use.

Multiple Customer Group Operation

A PBX shared by several different companies, each having separate consoles and trunks.

Multiple Domains

A set of domains on a single LAN, each of which has its own domain-wide post office. Hosts within each domain can exchange mail by going through one domain post office. Hosts in different domains must generally send mail though two intermediary post offices: the sender's domain post office and the receiver's domain post office.

Multiple Frequency-Shift Keying

MFSK. A form of frequency-shift keying in which multiple codes are used in the transmission of digital signals. The coding systems may use multiple frequencies transmitted concurrently or sequentially.

Multiple Homing

Connecting your phone so it can be served by one or several switching centers. This service may use a single directory number. It may also use several directory numbers (another term for phone numbers). It all depends on how you set the service up with your local phone company. The idea is to give you more ways of reaching the switched network ” in case one or more of your local loops breaks.

Multiple Listed Directory Number Service

Permits more than one listed directory number to be associated with a single PBX.

Multiple Low Speed CSU

MLSC. Specialized channel service unit (CSU) that combines several low speed lines onto one 64 kbps channel. 72. MULTIPLE NETWORK IDs: A feature that allows customers to implement multiple dialing plans with each one having its own network ID. This feature benefits extremely large corporations that want different divisions to have their own CVNS networks. Customers still only receive one bill.

Multiple Master Domain

Consists of two or more Single Master Domains connected through two-way trust relationships. See Trust Relationship.

Multiple Name Spaces

The association of several names or other pieces of information with the same file. This allows renaming files and designating them for dissimilar computer systems such as the PC and the Mac.

Multiple Parallel Processing

A method of fault tolerance used with host computers. Several CPUs cooperate to process data. It one CPU fails, its processing tasks are automatically assigned to other processors.

Multiple Protocol Router

A communications device designed to make decisions about which path a packet of information will take. The packets are routed according to address information contained within, and can route across different protocols.

Multiple Routing

The process of sending a message to more than one recipient, usually when all destinations are specified in the header of the message.

Multiple Spot Scanning

In facsimile systems, the method in which scanning is carried on simultaneously by two or more scanning spots, each one analyzing its fraction of the total scanned area of the subject copy.

Multiple Token Operation

Variant of token passing for rings in which a free token on a LAN is transmitted immediately after the last bit of the data packet, allowing multiple tokens on ring (but only one free token) simultaneously.

Multiple Tuned Antenna

An antenna with connections through inductances to ground at more than one point and so determined that the total reactances in parallel are equal to those necessary to give the antenna the desired natural frequency.

Multiplex

To transmit two or more signals over a single channel.
In the world of CATV and the explosion of choices that digital TV is bringing, to multiplex means to offer subscribers a choice of various starting times for movies and events.
A name for a collection of movie theaters under one roof.

Multiplex Aggregate Bit Rate

The bit rate in a time division multiplexer that is equal to the sum of the input channel data signaling rates available to the user plus the rate of the overhead bits required.

Multiplex Baseband

In frequency division multiplexing, the frequency band occupied by the aggregate of the signals in the line interconnecting the multiplexing and radio or line equipment.

Multiplex Hierarchy

In the U.S. frequency division multiplex hierarchy,

12 channels = 1 group

5 groups (60 channels) = 1 supergroup

10 supergroups (600 channels) = 1 mastergroup

6 mastergroups = 1 jumbo group

In contrast, the ITU-T standard says 5 supergroups (i.e. 300 channels) = 1 master- group.

Multiplexed Channel

A communications channel capable of carrying the telecommunications transmissions of a number of devices or users at one time.

Multiplexed Packet Switching

A network in which each node assembles/disassembles a packet containing data from different users. Data within the packet can have a different source and destination than other data in the packet. The one commonality is that the virtual circuits (logical pathways from the source to destination) all include the same internode link.

Multiplexer

Electronic equipment which allows two or more signals to pass over one communications circuit. That "circuit" may be a phone line, a microwave circuit, a through-the-air TV signal. That circuit may be analog or digital. There are many multiplexing techniques. When spelled "multiplexor," it refers only to optical units. See Frequency Division Multiplexing, Time Division Multiplexing and Pulse Code Modulation.
An RFID definition. An electronic device that allows a reader to have more than one antenna. Each antenna scans the field in a preset order.

Multiplexing

See Multiplex and Multiplex.

Multiplexing Efficiency

Figure of merit for multiplexers. The ratio of the aggregate channel input data rate to the composite output data rate. Many statistical multiplexers achieve a multiplexing efficiency of 8 or more.

Multipling

Connecting together identical purpose terminals of different switches to provide a singular input or output (usually called parallel connecting outside the telephone industry).

Multipoint Access

User access in which more than one terminal equipment (TE) is supported by a single network termination.

Multipoint Distribution Service

An FCC term for a fixed station operating between 2.15 and 2.162 GHz.

Multipoint Grounding System

A system of equipment bonded together and also bonded to the facility ground.

Multipoint Line

A single communications line to which more than one terminal is attached. Also called multidrop.

Multipoint to Multipoint Connection

A Multipoint to Multipoint Connection is a collection of associated ATM VC or VP links, and their associated nodes, with the following properties:

All Nodes in the connection, called endpoints, serve as a Root Node in a Point to Multipoint connection to all of the (N-1) remaining endpoints.
Each of the endpoints on the connection can send information directly to any other endpoint, but the receiving endpoint cannot distinguish which of the endpoints is sending information without additional (e.g., higher layer) information.

Multipoint/Multidrop

An arrangement of communications facilities ranging from across a floor to across the globe in which one common facility is shared by all; one station at a time, usually under central polling control, sometimes contention for the channel, as in many LANs, has a history running deep into telegraphic communications. Contrast: Point to Point.

Multiport Card

A circuit board with two or more ports for modems or other devices. Useful for enabling one PC to handle multiple incoming or outgoing calls at one time.

Multiport Repeater

A repeater, either standalone or connected to standard Ethernet cable, for interconnecting up to eight ThinWire Ethernet segments.

Multiport Switch

A local area network term. A device which allows packets to switch from one cable to another.

Multiprocessing

A type of computing characterized by systems that use more than one CPU to execute applications. Multi processing is not multi tasking, which is the ability to have more one application running on a system at the same time. The technique is not associated with multi processing, nor does it require multi processing to take place. Multi tasking typically uses a computer with one CPU (e.g. your desktop or laptop). Multi processing uses a computer with several CPUs, often a server. See Multi-Processing, Multi-Tasking and Multi-Threaded.

Multiprotocol Over ATM

MPOA. A proposed ATM Forum spec that defines how ATM traffic is routed from one virtual LAN to another. MPOA is key to making LAN emulation, Classical IP over ATM, and proprietary virtual LAN schemes interoperate in a multiprotocol environment. At this point, its unclear how MPOA will deal with conventional routers, distributed ATM edge routers (which shunt LAN traffic across an ATM cloud, while also performing conventional routing functions between non-ATM networks), and route servers (which centralize lookup tables on a dedicated network server in a switched LAN).

Multiprotocol Message Routers

Multipurpose Internet Mail Extension

MIME. An extension to electronic mail (Internet and other e-mail systems) which provides the ability to transfer non- ASCII data, such as graphics, software, audio, video, binary and fax. MIME was developed and adopted by the Internet Engineering Task Force. It was designed for transmitting mixed-media files across TCP/IP networks. The MIME protocol, which is actually an extension to SMTP, covers binary, audio and video data. Essentially what happens with MIME is that you pick a binary file (any file that isn't ASCII) to send along with your e-mail. Your e-mail software then converts your binary file to ASCII text which can easily be transmitted across one or more e-mail systems. All e-mail networks will transmit ASCII (i.e. ASCII 128 and below). The technique that makes MIME encoding possible is called UUencoding. Here is an example. Notice that every line begins with a M. Every line is the same length. At one end you UUencode the file (and it looks as below). When you receive the file, you must UUdecode it. Mostly the coding and encoding is done automatically by your e-mail program. Sometimes you must decode it manually. Don't try and UUdecode the following file. It won't work. I chopped the middle of the file out. I'm running it below purely as an example. See UUEncode and MIME.

Multiprotocol Label Switching

See MPLS.

MultiPulse-Maximum Likelihood Quantization

See MP-MLQ.

Multipurpose Internet Mail Extension

See MIME and the next definition.

Multipurpose Internet Mail Extensions Mapping

MIME mapping. A way of configuring browsers to view files that are in multiple formats. An extension of the Internet mail protocol that enables sending 8-bit based e-mail messages, which are used to support extended character sets, voice mail, facsimile images, and so on.

Multiserver Network

A network that uses two or more file servers.

Multisession

An incrementally updated Kodak Photo CD. See Multi-Session for a fuller explanation.

Multislacking

When an employee has two browser windows open, a non-work- related site on top o f a productive one, and quickly clicks on the legitimate site whenever the boss is nearby. Definition courtesy Wireless Magazine.

Multistage Dialing

Multistage Queuing

This a term typically used in Automatic Call Distributors. It is the ability to array a number of agent groups in a routing table. The notion of multiple agent groups being addressed may mean that the system may be able to "look-back" and "look forward" as it searches for a free agent in the right group to take the call presently holding.

Multitasking

Multithreaded

See Multi-Threaded.

Multiuser

A computer that can support several workstations operating simultaneously.

MUMPS

Massachusetts General Hospital Utility Multi-Programming System.

Munge

Munge is a verb meaning to render information unrecognizable. "Address munging," which also is incorrectly called "spam blocking," is the practice of monkeying around with an e-mail address so that its form is unrecognizable to computers but remains recognizable to humans . For example, you might take the e-mail address foo@foo.com and munge it into foo@foo.com.kill-spam. This munged address absolutely cannot be interpreted by a computer, but a human being can figure out the real address rather quickly. The basic reason for munging an e-mail address is to keep spammers from harvesting addresses from Usenet sites, putting you on a distribution list and flooding your mailbox with spam mail. The basic reason for not munging is that it makes it impossible for anyone to automatically respond to your e-mails. According to legend, MUNG originated at MIT as an acronym for "Mash Until No Good." See also Foo and Spam.

Muriel

Muriel Fullam worked for me for ten years before she worked with me on this dictionary. That had to be the longest apprenticeship ever. It shows. She has now worked for me for over 20 years. She is married to Jerry Fullam who is absolutely the best husband and will love it when he sees his name here. Christine is Muriel's daughter and she now publishes this dictionary.

Murphy's Law

When something can go wrong, it will. Compare with the Gotcha Law.

MUSE

MUltiple Sub-Nyquist Samplying Encoding. The Japanese bandwidth compression algorithm for analog HDTV transmission. The Japanese began work on analog HDTV in 1968, and demonstrated it in Washington, D.C. in 1987. The Japanese system ultimately was rejected for use in the U.S., in favor of a digital standard proposed by The Grand Alliance. The Japanese government invested over US$1 billion in the project. See also The Grand Alliance.

Mushroom Board

Also called a white board or peg board. This is placed between termination blocks to support route crossing wire.

Mushroom Strategy

A technique for dealing with dissident shareholders, recalcitrant employees and difficult families. The strategy is threefold: Keep everyone in the dark, feed them a lot of organic bovine waste (i.e. bullshit) and harvest them (i.e. bring them into the real world) when they are truly ripe, i.e. when you're ready to bring them out of their misery, or ignorance. The names derives from techniques used for growing mushrooms.

Music Source

An external music source such as a radio, can be connected to the Key Service Unit for Music on Hold, Background Music, or both.

Music-On-Camp

Audio source input for use with attendant camp-on. See also MUSIC-ON-HOLD.

Music-On-Hold

Background music heard when someone is put on hold, letting them know they are still connected. Some modern phone systems generate their own electronic synthesized music. Most phone systems have the ability to connect any sound-producing device, e.g. a radio or a cassette player. Most companies, unfortunately , devote little attention to the sound source they select. Sometimes competitors will deliberately advertise on the radio station that callers will hear on hold. Thus, Macys is now selling Gimbels. It's better to use pre-recorded music. Better yet are tapes of "specials" and other happenings around your firm. Use the "Music-on-Hold" feature as another method of selling. "Ask the operator about our special on ladies' underwear." "Ask our operator to send you a copy of our latest annual report."

Musical Chair Stocks

When the music stops, the last one holding the stock is bankrupt. This Aphorism, which refers to the phenomenon of forever- rising Internet stocks, which happened in the fall of 1998, came from the best stockbroker in North America, Todd Kingsley of Smith Barney in Washington, D.C. I know he's the best, because he, modestly, told me so.

Musical Instrument Digital Interface (MIDI)

A standardized communications protocol. MIDI files contain musical note information and other performance data that can "play" a MIDI instrument or sound module to produce music.

Must Carry Signals

A term from the 1992 Cable Act, it refers to a cable system's mandatory signal carriage of both commercial and noncommercial television broadcast stations that are "local" to the area served by the cable system.

Mute

A feature which disconnects the handset microphone or speakerphone microphone so that side conversations won't be heard.

Mutual Capacitance

The capacitance between two conductors when all other conductors, including the shield, are short circuited to ground.

Mutual Fund

A portfolio of stocks managed by a professional investment company for a management fee. Investors purchase shares in the fund, hoping that the professionals managing the fund will do better than the individual investors could, had they bought stocks individually. These days mutual funds tend to specialize ” in stocks of telecommunications companies, for example.

Mutual Synchronization

A timing subsystem not employing directed control, by which the frequency of the clock at a particular node is controlled by some weighted average of the timing on all signals received from neighboring nodes.

Mutually Synchronized Network

A network-synchronized arrangement in which each clock in the network exerts a degree of control on all others.

Mutually Exclusive

If there are two or more ways in which an event can occur then each way is mutually exclusive of the other way. The probability of the event occurring is the sum of the probabilities of the two or more ways.

MUX

See Multiplexer.

MVIP

Multi-Vendor Integration Protocol. Pronounced M-VIP. MVIP is a family of standards designed to let computer telephony products from different vendors inter-operate within a computer or group of computers. MVIP started in 1990 with a computer telephony bus for use inside a single computer. Picture a printed circuit card that fits into an empty slot in a personal computer. The slot carries information to and from the computer. This is called the data bus. Printed circuit cards that do voice processing typically have a second "bus" ” the voice bus. That "bus" is actually a ribbon cable which connects one voice processing card to another. The ribbon cable is typically connected to the top of the printed circuit card, while the data bus is at the bottom. As of this writing, there are at least four such buses defined. Several (AEB, PEB, SCSA) have been defined by Dialogic Corporation, Parsippany, NJ for connecting devices with Dialogic products and Dialogic compatible devices. There is also an organization called the ECTF which helps promulgate buses. The MVIP Bus was defined by Natural MicroSystems, Natick, MA with assistance from Mitel, Promptus Communications and Rhetorex as a vendor-independent means of connecting telephony devices within a computer chassis. MVIP was introduced by a seven- company group in 1990 and has been distributed by Natural MicroSystems, Mitel and NTT International (part of the Japanese telephone company). By July 1996, MVIP had over 170 companies manufacturing over 300 board-level MVIP products including telephone line interfaces, voice boards, FAX boards, video codecs, data multiplexers and LAN/WAN interfaces. MVIP now has its own trade association, the Global Organization for MVIP (see GO-MVIP), which develops extensions such as higher-level APIs and multi-chassis switching. Here is a write-up on the original MVIP Bus from Mitel's Communicating Objects Division:

"The MVIP Bus consists of communications hardware and software that allows printed circuit cards from multiple vendors to exchange information in a standardized digital format. The MVIP bus consists of eight 2 megabyte serial highways and clock signals that are routed from one card to another over a ribbon cable. Each of these highways is partitioned into 32 channels for a total capacity of 256 full-duplex voice channels on the MVIP bus. These serial link from one card to another. They are electronically compatible with Mitel's ST_BUS specification for inter-chip communications. By letting expansion cards exchange data directly, the MVIP bus opens the PC architecture to voice/data applications that would otherwise overburden the PC processor with data transfers. The MVIP bus is equivalent to an extra backplane that is capable of routing circuit switched data.

"MVIP systems generally have two types of cards ; network cards and resource cards. They differ by the switching they provide and in the way they are wired to the bus. Network cards almost always provide more flexible switching and can drive either the input or the output side of the bus, although they usually drive the output side of the bus. Resource cards usually provide very little switching and are only able to drive the input side of the bus. Resource cards usually rely on the network cards to do most or all of the switching on the MVIP bus."

According to Brough Turner, chairman of the GO-MVIP Technical Committee, MVIP Evangelist and vice president of Natural MicroSystems, "The original MVIP bus distributes switching elements but only requires switches on telephone network interface cards. This has simplified access to MVIP for many communications service providers and has permitted easy inter-connection of pre-existing and proprietary technology to the common bus. More recently, the Flexible MVIP Interface Circuit (see FMIC) has reduced the complete MVIP interface, including clocks and switching, to one chip, further simplifying MVIP connections.

"MVIP's distributed switching architecture provides software controlled digital switching within the PC chassis. MVIP software driver standards simplify access for application developers and support the integration of components from multiple vendors. As a result of work by more than a dozen companies active in the GO-MVIP Technical Committees, MVIP now addresses multi-chassis connections and higher-level APIs. Multi-Chassis MVIP (MC-MVIP) provides telephony connections and distributed digital switching between MVIP-based PCs and supports interconnection of MVIP PCs with proprietary telephony equipment including PBXs, ACDs, and voice processing systems. MC-MVIP includes redundant clocks and specifically permits plugging and unplugging connections while a multi-chassis system is operating. This allows application developers to construct fault-tolerant systems."

Since the original MVIP standard (now known as MVIP-90), the GO-MVIP Technical Committee has developed several standards which offer significant improvement. H-MVIP (High-Capacity MVIP) was approved in 1995 as a single-chassis standard which increases the call capacity of MVIP from 512 to 3,072 time slots. Additionally, four draft standards have been developed for MC-MVIP (Multi-Chassis MVIP). Those standards address operation and synchronization of MVIP in a multi-chassis environment over twisted pair and fiber (FDDI-II and SDH/SONET), with MC4 addressing ATM networking involving both SVCs and PVCs. See FMIC, GO-MVIP, NMS, NTT, PEB and SCSA.

MVL

Multiple Virtual Line, one of several modulation schemes being tried for DSL circuits. See Digital Subscriber Line.

MVNO

A mobile virtual network operator (MVNO) is an organization that buys minutes and services wholesale from an existing carrier (or carriers) and resells them under its own brand. Under GSM, for example, it may issue its own SIM card. A MVNO is basically a reseller. It does not have radio frequency (spectrum). it doesn't have its own communications plant. It usually has its own billing system. See SIM Card.

MVPD

Multichannel Video Program Distribution. It is provided by cable and satellite. See IB docket No. 95-168 or PP docket No. 93-253 In the Matter of Revision of Rules and Policies for the Direct Broadcast Satellite Service before the FCC.

MVS

Multiple Virtual Storage.

MW

Abbreviation for Milliwatt.

MWI

Message Waiting Indication. A fancy way of saying a light on a phone, a buzzing sound when you pick up the phone (also called a stutter dial tone), a message on a screen on your phone or a message on your PC telling you have a voice mail. In short, some way of telling you that you received a message while you were out or on the phone.

MX Records

Mail Exchange Records. All machines (i.e., host computers) that are connected directly to the Internet have IP (Internet Protocol) addresses. The DNS (Domain Name Servers) translate the "names" of the machines from URLs (Uniform Resource Locators), such as Harry_Newton@TechnologyInvestor.com, into the dotted decimal notation characteristic of the IP addressing scheme. Those machines that are directly connected to the Internet have both their URLs and their IP addresses stored in the DNS as "A Records" (Address Records). Machines that are not directly connected, have their address translation information stored as "MX Records." The MX Records point to the IP address of the mail host (i.e., the machine that is accepting mail for that target machine). Actually, multiple mail hosts usually are identified, in order of precedence (i.e., priority); that way, mail still can reach the target machine in the event that the primary mail host is out of service for some reason. The mail hosts commonly are in the form of ISP (Internet Service Provider) e-mail servers that receive your mail, store it, and download it to you when you dial in via modem or turn on your client computer connected to the ISP via DSL or a cable modem. See also A Records, CNAME Records, DNS, and URL.

MX3

A designation for a multiplex which interfaces between any of the following circuit combinations: 28 DSIs to one DS3 (M13), 14 DSICs to one DS3 (MC3), or 7 DS2s to one DS3 (M23).

MXR

Multiplexer.

MZI

Mach Zehnder Interferometer.