M

[This is preliminary documentation and subject to change.]

MBONE

See multicast backbone.

merchant server

A server that enables user purchases in a secure fashion.

Microsoft Broadcast Data Network

(MSBDN) A high-bandwidth broadcast network, capable of sending 2 to 25 megabits per second, or 22 to 270 gigabits per day. MSBDN is designed to use strong Data Encryption Standard (DES) encryption to secure valuable goods and services so that only paying subscribers have access to them. This high level of security will make MSBDN a suitable channel for delivery of software and other expensive digital goods and services that would otherwise be vulnerable to theft.

Microsoft Multicast Router

(MMR) A component that enables a content server to send a data stream to a multiplexer or other broadcast output device. The MMR calls a virtual interface to package and transmit a stream at the appropriate rate and in the appropriate packet format.

Microsoft WebTV for Windows

A component of the Microsoft® Windows® 98 operating system that enables users to select television channels and that displays interactive television programs. Microsoft® WebTV® for Windows uses an ActiveX control to display conventional television shows, and it hosts a Hypertext Markup Language (HTML) browser to display interactive content for those shows at the same time.

minidriver

A hardware-specific dynamic-link library (DLL) that uses a Microsoft-provided class driver to accomplish most actions and provides only device-specific controls. In Windows Driver Model (WDM), the minidriver registers each device with the class driver, which creates an object for each device. The minidriver uses these device objects to make calls to the operating system.

miniport

Software that communicates with a specific piece of peripheral hardware through a port. A miniport translates all applicable commands that come through the port from the computer into the appropriate hardware commands. This miniport functionality means the port does not require extensive information about each piece of hardware it supports. See also NIC miniport.

miniport driver

See miniport.

MMDS

See Multichannel Multipoint Distributed System.

MMR

See Microsoft Multicast Router.

MPEG

(Motion Pictures Experts Group standard) MPEG-1 is a standard designed for video playback of NTSC quality from CD-ROM. MPEG-1 provides video and audio compression at rates up to 1.8 megabits per second. MPEG-2 provides higher video resolutions and interlacing for broadcast television and high-definition television (HDTV). Both standards were created by the Motion Pictures Experts Group, an International Standards Organization/International Telegraph and Telephone Consultative Committee (ISO/CCITT) group set up to develop motion video compression standards.

MPT

See Multipacket Transport.

MSBDN

See Microsoft Broadcast Data Network.

MTS

A stereo encoding standard used with analog audio and video transmissions.

multicast

A point-to-many networking model in which a packet is sent to a specific address, and only those computers that are set to receive information from this address receive the packet. On the Internet, the possible IP multicast addresses range from 224.0.0.0 through 239.255.255.255. Computer networks typically use a unicast model, in which a different version of the same packet is sent to each address that must receive it. The multicast model greatly reduces traffic and increases efficiency on such networks.

multicast backbone

(MBONE) A virtual, multicast-enabled network that works on top of the Internet. The most popular application for the MBONE is video conferencing, including audio, video and whiteboard conferencing. However, the essential technology of the MBONE is simply multicast — there is no special support for continuous media such as audio and video. The MBONE has been set up and maintained on a cooperative, volunteer basis.

Multichannel Multipoint Distributed System

(MMDS) Also known as wireless cable, this system broadcasts terrestrial or satellite microwave transmissions directly to consumers' homes. The Federal Communications Commission (FCC) invented this system in the 1980s to provide competition to traditional cable television companies. There are currently 33 MMDS channels allocated, most in the 2.5-gigahertz band.

multihomed computer

A computer connected to two or more networks or having two or more addresses on one network. For example, a network server may be connected to multiple local area networks (LANs). Generally, a multihomed computer may send and receive data over any of its connections but does not necessarily route traffic for other computers.

multimedia

Online material that combines text and graphics with sound, animation, or video, or some combination of the three.

Multipacket Transport

(MPT) A data link adaptation layer developed by Microsoft that resides above the data link layer of a network with large, fixed-size packets, such as a satellite system. MPT allows higher-layer protocols such as Internet Protocol (IP) to exist independently of, and be unaffected by, the underlying network.

multiplexer

In general terms, a device for funneling several different streams of data over a common communications line. In the case of Broadcast Architecture, a multiplexer combines multiple television channels and data streams for a single transponder.