Maintenance Limit-Marquee Client

Maintenance Limit

A Verizon definition. The maximum margin, value, or deviation associated with normal in-service performance.

Maintenance of Service Charge

MSC. A Verizon definition. A charge to the CLEC or Reseller when the field technician is dispatched to remedy a problem found in the customer premise equipment (at the end user 's premises).

Maintenance Release

An euphemism for a new piece of software that fixes a buggy piece of old software. When software is released, it's usually buggy . A maintenance releases attempts to fix the bugs . A more correct term for the new software would be a "bug fix." A maintenance release often carries the number one as the second digit after the decimal point, e.g. 3.51 or 4.01.

Maintenance Services

In IBM's SNA, network services performed between a host SSCP and remote physical units (PUs) that test links and collect and record error information. Related facilities include configuration services, management services and session services.

Maintenance Termination Unit

MTU. A MTU is an electronic circuit that is owned and deployed by a telephone company to aid in fault sectionalization and is installed at the network interface. The MTU should meet the requirements of Bellcore Technical Advisory TSY-000324 and be testable with the Mechanized Loop Test System (MLT). The MTU is designed to work on single line residence or business service. Bellcore is now called Telcordia Technologies.

Maintenance Update

A euphemism for a piece of software which fixes bugs in a previously-released version of the software. A maintenance update rarely has any new features and rarely costs anything. Software companies send them because they find bad bugs in their software and want to fix those bugs asap, or because they can't stand the heat from complaining customers.

Maintenance Usage

A telephone company term. The amount of time, measured in CCS that equipment components are removed from service. Can be caused by equipment malfunction, routine maintenance, transitions, etc.

Major Trading Area

Major Trading Area. The U.S. and its territories are divided into 51 areas, called MTAs, which are based on Rand McNally's analysis in identifying areas of economic integration and documented in Rand McNally's (1-800-284-6565) "Commercial Atlas and Marketing Guide." (Note: the FCC modified Rand McNally's proposed 47 MTAs to 51 to handle Alaska, Puerto Rico, etc.) An MTA consists of an integer number of BTAs; BTAs are never split between MTAs. For example, the Chicago MTA consists of 18 BTAs (including the Chicago BTA) and 84 counties. Each MTA consists of one or more Basic Trading Areas (BTAs). For instance, the Chicago MTA includes 18 BTAs such as Rockford BTA, Springfield BTA, Ft. Wayne BTA, etc. Milwaukee is another MTA.

Majordomo

Translated from Latin as "master of the house". Majordomo is a free- ware e-mail list server program that maintains multiple mailing lists and automatically redistributes e-mails to all members of the list. It automatically interprets (i.e. understands) commands in e- mails sent to it by individuals who wish to subscribe to, unsubscribe from, receive periodic summaries of, or otherwise become associated with a mailing list. It also handles the mass mailing of messages to members of the list. Written in the PERL language, Majordomo originated in the UNIX environment, although it in can run under any operating language with a PERL interpreter. You find Majordomo all over the Internet. For an example of how Majordomo mailing lists work, here's a note on subscription information for an electronic newsletter called WinNews published by Microsoft. "If you know someone who might be interested in WinNews, please instruct them to:

1. Send Internet e-mail to: [e-mail].

2. Send the message from the account that you wish to subscribe (some people use more than one e-mail account).

3. Subject line should be blank.

4. Body of message should ONLY have in the text: SUBSCRIBE WINNEWS If you wish to stop receiving WinNews, send mail to [e-mail] with a blank subject line and the body of the message should only save in the text: UNSUBSCRIBE WINNEWS."

Make Busy

To make a communication circuit unavailable for connection. The technical term for taking the phone off the hook and leaving it off hook.

Malicious Call Tracing

An ISDN service which enables to User to Network message to be sent while the call is in progress, ensuring that origination details are captured at the local exchange.

Malware

Geekspeak for software with a malicious intent i.e. viruses, trojan horses etc.

MAM

Major Account Manager.

MAN

Metropolitan Area Network. A high-speed data intra-city network that links multiple locations within a campus, city, or LATA. Typically extends as far as 50-kilometers, operates at speeds from 1 Mbit/s to 200 Mbps and provides an integrated set of services for real-time data, voice and image transmission. The IEEE 802.6 standard defines MAN standards and SMDS is the MAN service offered by local phone companies. Private and public MANs may use the ANSI FDDI standard.

Man-In-The-Middle Attack

A form of active wiretapping attack in which the attacker intercepts and selectively modifies communicated data to masquerade as one or more of the entities involved in a communication association.

Man Machine Interface

A term coined by James Martin to designate the ease (or lack of ease) of a person working with a computer.

Man Page

Manual page. On-line documentation that commonly comes bundled with computers running Unix.

Managed Circuit

A managed circuit is a fancy name for a phone line which the supplier of the circuit, i.e. your phone company carrier, provides you. This is probably one of the dumbest definitions in this dictionary.

Managed Earnings

Public companies can change what they report as earnings and profits by delaying and accelerating expenses and sales. They can also schedule write- downs at the right and wrong time. In short, they can manage their earnings, making them smaller or larger, depending on their needs for their shareholders and the public.

Managed Modem Service

A managed service is a carrier service offering, which essentially involves the carrier's owning the requisite equipment and managing certain aspects of the service offering. It's a form of outsourcing. Consider the traditional means by which an ISP supports dial-up access: At the ISP premises are one or more modem banks installed in one or more access routers, which are connected to the edge of the PSTN by one or more dial-up access circuits. The circuits are in the form of either individual single-channel analog circuits or, more commonly, one or more channelized T-carrier circuits, with each voice-grade channel supporting a single connection at a maximum rate of 56/64 Kbps. Seldom does a given connection actually make effective use of the channel capacity, at least over a period of time. All traffic from all ISP customers is directed to the ISP location; traffic intended for the Internet is then rerouted to the Internet over an unchannelized T-carrier circuit. Now consider a managed modem service provided by a PSTN carrier: The carrier places one or more modem banks in its Central Office. The ISP's dial-up customers' calls connect to the network-based modem banks, where they are converted into a TCP/IP packet format by the carrier's network-based router. Traffic intended for the ISP is (e.g., outgoing or incoming e-mail) is sent over an unchannelized T-carrier circuit to the corresponding router at the ISP location. Traffic from multiple dial-up users is aggregated at the edge of the carrier network, optimizing the usage of the T-carrier access circuit. Traffic intended for the Internet or World Wide Web is routed directly in that direction, without looping through the ISP. Authentication is provided by the ISP's authentication server, which commonly would be in the form of a RADIUS (Remote Access Dial-In Authentication Server) server. The carrier provides technical support for the modem bank, the unchannelized T-carrier circuit, and all routers involved, all of which network elements it owns and leases to the ISP. The carrier supports a variety of access protocols, including V.34/V.34+/V.90 modems and ISDN. See also Authentication, ISDN, ISP, Modem, RADIUS, Router, Server, and T-carrier.

Managed Object

A telephone company AIN term. If you understand this definition, you're a better person than I am. Given a Common Management Information Services Element (CMISE) interface between an Operations System and a network element or network system, a managed object is an abstract representation of a physical or logical network element or network system resource. The managed object constitutes an Operations Systems' view of that resource from the CMISE operations system and a network element or network system interfere. It can also be called a Managed Object Instance to emphasize the distinction between Managed Objects and Managed Object Classes.

Managed Object Class

A telephone company AIN term. A group of managed objects that all have the same types of attributes, same permissible ranges of attribute values, same semantics and pragmatics for interpretation of Common Management Information Services Element (CMISE) requests , and the same capabilities for issuing event reports .

Managed System

An entity that is managed by one or more management systems, which can be either Element Management Systems, Subnetwork or Network Management Systems, or any other management systems.

Management Domain

MD. An X.400 term describing a set of messaging systems. At least one system contains, or realizes, an MTA (Messaging Transfer Agent) managed by a single organization. It is a primary building block in the organizational construction of an MHS (Messaging Handling System), referring to an organizational area for the provision of messaging services. MD is used in a similar manner in X.500, consisting of at least one DSA (Directory System Agent). A management domain may or may not be identical with a geographical area. See Domain.

Management Extranet

A management extranet uses the Web to electronically join entire supply chains, so the IS department can tie itself via the Web to its suppliers and service providers. See also Management Intranet.

Management Information Base

See MIB.

Management Information System

MIS. Management information provided by computer data processing. Once upon a time called data processing.

Mantelpiece

The shelf above, or the finish around, a fireplace is called a "mantel- piece" because at one time people hung their coats (or "mantles") over the fireplace to dry them.

Management Intranet

A management intranet uses World Wide Web technologies and techniques to integrate disparate management tools and databases, provide universal access to documentation and promote distributed collaboration among far-flung IS support people. See also Management Extranet.

Management Plane

An element of the ATM Protocol Reference Model, the Management Plane addresses the management of the ATM switches and hubs, cutting through all 4 layers of the model. Included in Management Plane functions are Operation, Administration and Maintenance (OA&M) functions.

Management Services

In IBM's SNA, network services performed between a host SSCP and remote physical units (PUs) that include the request and retrieval of network statistics.

Management System

An entity that manages a set of managed systems, which can be either NEs, subnetworks or other management systems.

Manchester Encoding

A digital encoding technique in which each bit period is divided into two complementary halves . A negative-to-positive (voltage) transition in the middle of the bit period designates a binary "1" while a positive-to-negative transition represents a "0". This encoding technique is self-clocking (i.e., the receiving device can recover transmitted clock from the data stream). See also CDR.

Mandatory Dialing

When permissive dialing is over after an area code change, it becomes mandatory dialing. See Permissive Dialing.

Mandrel Wrapping

A mandrel is a cylindrical shaft or bar. In machining, a mandrel is inserted into the piece you are working on. This holds it in place during machining. In multimode fiber optics, mandrel wrapping is a technique used to modify the modal distribution of a propagating optical signal. Basically you wrap a specified number turns of fiber on a mandrel of specified size , depending on the fiber characteristics and the desired modal distribution. It has application in optical transmission performance tests, to simulate, i.e., establish, equilibrium mode distribution in a launch fiber (a fiber used to inject a test signal in another fiber that is under test). If the launch fiber is fully filled ahead of the mandrel wrap, the higher-order modes will be stripped off, leaving only lower-order modes. If the launch fiber is underfilled, e.g., as a consequence of being energized by a laser diode or edge-emitting LED, there will be a redistribution to higher-order modes until modal equilibrium is reached.

Manhole

An underground concrete vault in which cables may be spliced, and transmission equipment (repeaters, etc.) may be located. A manhole is used in conjunction with an underground cable running in conduits . A manhole cover is typically round. The reason? Round is the only shape that won't allow the cover to fall through the hole and hurt some poor soul and because it's easy to move them by rolling them. Most countries have round manholes. The Italians have square ones in some cities. I don't know why. These days there is some movement to call them personalholes. God forbid .

Manhole, a small vault used by one or several workers to access and service equipment i.e.; telephone, sewer or other utilities. It is usually covered by a lid smaller than the inside dimension of the vault.

Manhole cover, normally a heavy steel lid of various geometric shapes. They are designed to rest flush with the outside surface. Two most common shapes are the circle and the square. However, rectangles and triangles are also used. The equilateral triangle and the circle share a similar property. They will not fall through the smaller opening they sit on and damage equipment inside (no one replaces a lid with someone still inside the vault). The square cover is often hinged and sometimes bolted closed (high voltage danger is an example).

Notes of interest: Engineers continue to advance the manhole and cover. It controls waterflow by location such as being in the highest or lowest position on the street. It is almost always connected to a storm drain since the lid and vault are usually not watertight. Round lids are the images most people first envision. Larger round lids with smaller singleman lids are used to facilitate equipment movement. Hole are build into lids to allow workers to use a grab bar for access and movement. Rarely does a worker lift and carry or even roll a lid anywhere , rather they drag it. Ramped skids that radiate outwards from center on the bottomside are being built into newer round lids to help the round lid do what it does best and that is to allow the worker to easily reinstall the cover and close the job.

Manual Exclusion

A PBX extension user, by entering a certain code, can block all other phones on that line from entering the call. Assures privacy on the line.

Manual Gain Control

MGC. There are two electronic ways you can control the recording of something ” Manual or Automatic Gain Control (AGC). AGC is an electronic circuit in tape recorders , speakerphones and other voice devices which is used to maintain volume. AGC is not always a brilliant idea since it attempts to produce a constant volume level. This means it will try to equalize all sounds ” the volume of your voice and, when you stop talking, the circuit static and/or general room noise which you undoubtedly do not want amplified. Sometimes it's better to have quiet, when you want quiet. Manual Gain Control is preferred in professional applications. Manual Gain Control is simply an elegant way of saying there's a record volume control. Never record a seminar or speech using AGC. The end result will be decidedly amateurish.

Manual Hold

The method of placing a line circuit on "hold' by activating a non-locking "hold" button on the phone, usually one colored red.

Manual Intercom

A crude, single- path communications link between telephones without the ability to signal the receiving party.

Manual Modem Adapter

An external device for the Merlin key system from AT&T. It allows connection of single line accessories to any Merlin telephone. The device, in effect, draws a standard tip and ring line out of the Merlin proprietary cabling/signaling scheme. Some other key systems have similar devices. Comdial calls theirs a "data port" and their phones contain extra RJ-11 jacks .

Manual Originating Line Service

The attendant must complete all outgoing calls. All other calls are blocked. This "feature" is used to cut down on long distance phone abuse. There's a wonderful story. When many of the PBXs in Europe went from manual originating line service to automatic dial "9" long distance, the number of long distance calls doubled within two months. Some of these calls were legitimate . Some were not. How much abuse there was varied from company to company. Typically, those companies with employees who were more bored suffered (or enjoyed?) more abuse.

Manual PBXs

Refers to PBXs which are not automatic and which require that all calls, including intercom calls, be placed through the attendant. Such PBXs are still used today, though in limited applications. You can still find manual PBXs in vacation hotels, nursing homes and in the data communications departments of some firms, who use manual PBXs as manual dataPBXs. These are especially useful in places where long data calls and sold metal-to-metal connections are an advantage.

Manual Ring Down Line

Two phones connected by a pair of wires and a battery. Signaling is performed manually by flipping a switch on and off which connects and disconnects the battery. This causes a weak ringing. It's used by rescue teams in caves and mines because radio range is often limited.

Manual Ring Down Tie Trunk

A direct talk path between two distant phones. Signaling must be done manually from either phone. Contrast this with Automatic Ringdown Tie Trunk, in which the signaling occurs the moment one of the phones is lifted off hook.

Manual Signaling

Pushing a button on a telephone sends an audible signal to a predetermined phone. Manual signaling can be used for secretary/boss communications.

Manual Telephone

A telephone without a dial. Taking the receiver off hook automatically rings a predetermined number. A courtesy phone.

Manual Terminating Line Service

Provides extension lines that require all calls be completed by the attendant. For a better explanation see Manual Originating Line Service.

Manual Tie Line

A tie line which requires the assistance of an attendant at both ends of the circuit in order to complete a connection; a manual tie lie is incapable of passing dialing down the link. Also called Manual Trunk, Ringdown Trunk, Ringdown Tie Line.

Manufacturing Automation Protocol

MAP. A protocol initially developed as an internal specification for its own factory floor equipment and now championed by General Motors as the industry standard to facilitate communications among the diverse automation devices found in production environments. AT&T, IBM and DEC have endorsed this standard and have already or will introduce MAP-compatible products. TOP (Technical Office Protocol) was initiated by Boeing Computer Services (one of the nine companies that helped form the MAP Users Group in 1984) and is designed for use in the engineering and office environment and to move information from the factory floor to other parts of the company. Implementation of these protocols would lead to GM's factory of the future concept.

Manufacturing Message Format Standard

An Application Layer protocol developed as a part of MAP to provide a syntax for exchanging messages in the manufacturing environment.

Manufacturing Message Specification

MMS. An International Standards Organization (ISO) application layer protocol that defines the framework for distributing manufacturing messages within a network. This specification is used in MAP 3.n.

MAP

1. A new term for multiplexing, implying more visibility inside the resultant multiplexed bit stream than available with conventional asynchronous techniques.

2. Mobile Application Part. As defined by IS-41 (Interim Standard 41) a User Part of the SS7 protocol used in wireless mobile telephony. MAP standards address registration of roamers and intersystem hand-off procedures. As a query-and-response procedure, MAP makes use of TCAP (Transaction Capabilities Application Part) over the SS7 network. See also IS-41, SS7 and TCAP.

3. Maintenance and Administration Position. See MAP/MAAP below.

4. Manufacturing Automation Protocol. See that definition.

MAP/MAAP

Maintenance and Administration Panel. A device attached to a PBX to allow you to maintain and administer the system ” to change phone features, etc.

MAP/TOP

Manufacturing Automation Protocol/Technical Office Protocol.

MAPI

Microsoft's Windows Messaging Application Programming Interface, which is part of WOSA (Windows Open Services Architecture) and thus part of all Windows operating systems. MAPI is a set of API functions and as OLE interface that lets messaging clients, such as Microsoft Exchange, interact with various message service providers, such as Microsoft Mail, Microsoft Exchange Server, Microsoft Fax and various computer telephony servers running under Windows NT server. Overall, MAPI helps Exchange manage stored messages and defines the purpose and content of messages ” with the objective that most end users will never know or care about it. A friend of mine, who's a great programmer, Pete MacLean, explained MAPI as: MAPI is Microsoft's new foundation for a modular mail system. You can pick and choose among various email clients , address books, message stores (foldering systems), and transports (the message-service specific pieces) and build your own custom mail system. See also At Work, Microsoft Exchange, Windows 95, Windows Telephony and WOSA. The biggest explanation of MAPI is in the definition for Windows 95.

Mapping

1. In network operations, the logical association of one set of values, such as addresses on one network, with quantities or values of another set, such as devices on another network (e.g. name-address mapping, internetwork-route mapping).

2. A Novell NetWare term. To assign a drive letter to a chosen directory path on a particular volume of a particular file server. For example, if you map drive F to the directory SYS:ACCTS\RECEIVE, you will access that directory every time you enter "F:" at the DOS prompt. See also Drive Mappings.

3. In EDI (Electronic Data Interchange), mapping defines the translation between a company's unique data layout and an EDI formal structure.

4. The process by which the structure of a file is provided after the file has been compiled. A "map file" lists all of the program variables , and their memory addresses.

5. Translation from one programming language to another through the use of a compiler. For example, as translation from C to machine language is relatively easily accomplished, C is said to "map well." See also Compiler.

MAR

Major Account Representative.

Marriage

1. In Pennsylvania, Ministers are forbidden from performing marriages when either the bride or groom is drunk.

2. A second marriage is a triumph of hope over experience. ” Samuel Johnson, 1770.

MARS

Multicast Address Resolution Server. Mechanism for supporting IP multicast. A MARS serves a group of nodes (known as a cluster); each node in the cluster is configured with the ATM address of the MARS. The MARS supports multicast through multicast messages of overlaid point-to-multipoint connections or through multicast servers.

Marathon

A family of products that are combination fast packet multiplexer, data compression, voice compression and fax de-modulation devices that fit many, voice, data, fax and LAN "conversations" onto one leased circuit ” analog or digital. The idea of Marathon is to save money on long distance telecommunications charges. The Marathon family of products is made by Micom Communications Corporation, Simi Valley CA, now a subsidiary of Northern Telecom (Nortel).

Marconi, Guglielmo

Guglielmo Marconi, born in Bologna, Italy in 1874, was on a holiday when he read of the electromagnetic wave experiments of Hertz. This article established the thought in Guglielmo's mind that electromagnetic waves could free telegraphy from the wires and submarine cables, which at that time constrained its use. Finding out if electromagnetic waves could be used to communicate at a distance became an obsession for Marconi. His mother allowed him to use two large rooms on the top floor of their house as a laboratory. She also helped persuade Guglielmo's father to provide (albeit grudgingly) the money necessary for the batteries, wire and other equipment Guglielmo needed. Marconi started by repeating Hertz's experiments. His oscillator was an induction coil equipped with four spheres for the spark discharge . The frequency of the oscillations was in what we, today, call the VHF range. The detector he used with his receiving coil was a Branly coherer, similar to that used by Oliver Lodge. The coherer provided much greater sensitivity than the spark-gap equipped loop of wire Hertz had used. Marconi placed a curved metal detector behind his oscillator to direct the waves toward the detecting circuit. Soon, Marconi was able to cause a bell, located thirty feet away, to ring when the oscillator was keyed. Through trial-and-error experimentation, he was able to increase the sensitivity of the coherer significantly over what others had achieved. The following spring, Marconi took his experiments outdoors. Connecting metal plates to the oscillator's spark gap lowered the frequency and strengthened the intensity of the oscillations produced. Similar plates were connected to each side of the coherer. By chance, Marconi found that if one of the metal plates was elevated high in the air and the other was laid on the ground, the range at which oscillations could be detected increased to over one-half mile. Soon, the elevated plates at the oscillator and detector were replaced by long vertical wires. The plates which had lain on top of the ground now were buried. This arrangement increased the distance at which signals could be received to one and one-quarter miles. An intervening hill was found to be no barrier to the reception of the signals. The combination of using lower-frequency oscillations and using the Earth as an element in his antenna system were crucially important achievements. Another demonstration was held in March of 1897. This time longer wavelengths were used in conjunction with wire antennas raised some 120 feet above the ground by means of kites and balloons. This arrangement resulted in signals being received over a distance of four and one-half miles. In May of 1887, Marconi demonstrated that wireless signals could span significant lengths across water by sending signals between the shore and an island in the Bristol Channel, a distance of 8.7 miles. This was a crucial test because the submarine cable that normally provided communications to the island had failed several times in recent months. Repairing the cable was costly both in time and in money so Marconi's system must have appeared as an excellent alternative. Marconi established the Wireless Telegraph and Signa. Ltd. in July of 1897. In 1899, he changed the name of his company to The Marconi Wireless Telegraph Co. Ltd. A major goal Marconi had in mind was to show the value of wireless for communicating with ships. In 1897, he returned home to Italy to convincingly demonstrate that wireless could communicate between naval warships. The Italian Navy soon adopted the Marconi wireless system. In 1896, in England, Marconi obtained the first patent on the wireless. In 1901 he succeeded in transmitting signals across the Atlantic. In 1909 he received jointly with C. F. Braun the Nobel Prize in Physics. Marconi was made a Marchese and a member of the Italian senate. He died in Rome on July 20, 1937. See also TESLA, Nikola.

Margaret

From the Greek "margaron," translating to "pearl" in English. Margaret Hinano Horak is the lovely wife of Ray Horak, my Contributing Editor. Margaret is one-quarter Hawaiian, which makes the "pearl" thing especially appropriate. "Hinano" is the name her mother gave her. Margaret's mother was half Hawaiian, with some Swedish and Seneca Indian mixed in, but leaned very much toward the Hawaiian side. The meaning of "Hinano" is a bit unclear. It seems to refer to a native Hawaiian flower or plant, which apparently is extinct. Neither "Margaret" nor "Hinano" can adequately describe this loveliest of women. She has the luminescence of the finest pearl and the delicacy of the loveliest of flowers. Margaret is one of a kind, and Ray is the luckiest man ever to walk the face of the earth. (You can bet who wrote this objective definition.) See Ray.

Margin Account

A brokerage trading account that allows you to use borrowed money from your brokerage firm when buying stocks. Not always a good idea, since the stock may decline to where the value of your stock is what you owe your broker and your broker will sell your stock to allow him to get his money back. Meantime, you can lose your entire holdings. Or worse , if the stock falls fast, you may end up owing your broker money which you no longer have.

Marginal Cost

The cost of supplying an extra unit of output. The telecommunications transport business is the only one in the world where the marginal cost of providing an extra unit of product (i.e. a phone call) is zero. This makes for wonderful economics once your network is in place.

Marginalized

When they stop your salary, but give you a bigger title (also called being "kicked upstairs"), you have, in essence, been marginalized. You have been placed in a position of marginal importance. I included this definition, because one of my dearest friends just got marginalized. And he's too young to retire.

Marine Telephone

Marine telephones operate on assigned radiotelephone frequencies much as a radio broadcast does. Marine telephones can be used to contact other marine telephones or to reach land-based telephones through an operator.

MARISAT

A satellite for marine use. Conversations on MARISAT are crystal clear. Call Comsat and ask them for a demo call to a ship somewhere in the world. It's very exciting.

Marine Broadcast Station

A coast station which makes scheduled broadcasts of time, meteorological , and hydrographic information.

Marine Utility Station

A station in the maritime mobile service consisting of one or more hand-held radiotelephone units licensed under a single authorization. Each unit is capable of operation while being hand-carried by an individual.

Maritime Air Communications

Communications systems, procedures, operations, and equipment that are used for message traffic between aircraft stations and ship stations in the maritime service. Commercial, private, naval, and other ships are included in maritime air communications.

Maritime Broadcast Communications Net

A communications net that is used for international distress calling, including international lifeboat, lifecraft, and survival-craft high-frequency (HF); aeronautical emergency very high-frequency (VHF); survival ultra high-frequency (UHF); international calling and safety very high-frequency (VHF); combined scene-of-search-and-rescue; and other similar and related purposes. Basic international distress calling is performed at either medium frequency (MF) or at high frequency (HF).

Maritime Mobile Satellite Service

A mobile satellite service in which mobile earth stations are located on board ships; survival craft stations and emergency position-indicating radiobeacon stations may also participate in this service.

Maritime Mobile Service

A mobile service between coast stations and ship stations, or between ship stations, or between associated on-board communication stations; survival craft stations and emergency position-indicating radiobeacon stations may also participate in this service.

Maritime Radio Navigation Satellite Service

A radionavigation- satellite service in which earth stations are located on board ships.

Maritime Radio Navigation Service

A radio navigation service intended for the benefit and for the safe operation of ships.

Mark

1. A term that originated with the telegraph. It currently indicates the binary digit "1" (one) in most coding schemes. A space is zero in most coding schemes.

2. A call center term. To flag a record in a browse listing for some special purpose. Typically you mark a record that you want to copy information from. As long as the record is marked , you can continue copying the information to other records.

Marker

The logic circuitry in a crossbar central office that controls call processing functions. See Xbar.

Marker Beacon

A transmitter in the aeronautical radio navigation service which radiates vertically a distinctive pattern for providing position information to aircraft.

Marker Tape

A tape laid parallel to the conductors under the sheath in a cable imprinted with the manufacturer's name and the specification to which the cable is made. Other information such as date of manufacture may also be included.

Marker Thread

A colored thread lain parallel and adjacent to the strands of an insulated conductor which identifies the cable manufacturer. It may also denote a temperature rating or the specification to which the cable is made.

Market Order

When you place a "market order," you instruct your broker or brokerage service to buy or sell this stock at whatever price you can get it at.

Market Price

Prices set at market rates but, in most cases, are not permitted to be less than cost.

Market Research

Something the phone industry doesn't do ” as indicated by the design stupidities of most phones, including ” an upside-down keyboard, no backspace erase (except on cell phones), diminutive unreadable screens, voice mail jail, no dial by name (on most phones), dumb handsets that hurt your shoulder, no shoulder rests (on most phones), handset cords that are too short, etc. Don't get me started.

Marking Bias

The uniform lengthening of all marking signal pulses at the expense of all spacing pulses .

Mark-Hold

The normal no-traffic line condition where a steady mark is transmitted.

Markup

Special codes in a document that specify how parts of it are to be processed by an application. In a word-processor file, markup specifies how the text is to be formatted; in an HTML document, the markup specifies the text's structural function (heading, title, paragraph, and so on.)

Marquee

1. A region on a Web home page that displays a horizontally scrolling message.

2. In graphics software, a sizable and movable frame that identifies a selected portion of a bit-mapped image. The marquee frame can be rectangular in shape or, in some cases, irregular. A lasso tool, for example, enables you to select all contiguous portions of an image that share the same color .

Marquee Client

Webspeak for a customer whose name is recognizable to most Americans ” Coca Cola, McDonald's, Avis, etc. A company wishing to raise lots of money should have lots of marquee clients. It gives the company some credibility.