ation of voice and video information that is lending much of the power to multimedia communications Multiple Systems Operator When one cable company runs multiple cable systems, it creates what is referred to as a Multiple Systems Operator. MSOs benefit from economies of scale in areas of equipment procurement, marketing, management and technical expertise. Local decisions are left to the individual cable company operators. multiplex A method of transmitting multiple signals onto a single circuit in a manner SO that each can be recovered intact. multiplexer Electronic equipment that allows multiple signals to share a single communications circuit. Multiplexers are often called "muxes." There are many different types of multiplexers including T-1 and E-1 that use time division multiplexing, statistical and frequency Glossary of Terms division multiplexers, etc. Some use analog transmission schemes, some digital. A compatible demultiplexer is required to separate the signal back into its components. multiplexing The process of combining multiple signals onto a single circuit using various means. multipoint control unit A device that bridges together multiple inputs SO that more than three parties can participate in a videoconference. An MCU uses fast switching techniques to patch the presenters or speaker's input to the output ports representing the other participants. An ITU-T H.320-compliant MCU must meet the requirements of H.231 and H.243. Multirate ISDN A Bandwidth-on-Demand scheme in which telephone customers access, and subsequently pay for, ISDN bandwidth on an as-needed basis. multisensory Involving more than one human sense. - N- - N-ISDN Narrowband ISDN. Another name for conventional ISDN that defines bandwidths between 64 Kbps and 2.048 Mbps. narrowband Networks designed for voice transmission (typically analog voice), but which have been adapted to accommodate the transmission of low-speed data (up to 19.2 Kbps). Trying to get the existing narrowband public switched telephone network to transmit video 