MB (megabyte): a unit for measuring the size of electronic data. 1 MB = 1,024 kilobytes = 1,048,576 bytes = 8,388,608 bits.
MHEG-5: Interactive middleware devised by the Multimedia and Hypermedia information coding Expert Group. Deployed by On Digital (later ITV Digital), MHEG-5 is now the middleware on the UK DTT (Freeview) and Freesat platforms. It has also been adopted in New Zealand.
MHP (Multimedia Home Platform): interactive TV middleware designed as an opensource alternative to the proprietary systems elements of which form part of the US OpenCable Application Platform (OCAP). Its deployment has been disappointing and MHP was dealt a potentially fatal blow by a dispute over patent rights.
Modem: A modem converts a digital bit stream into analogue signal and converts analogue signals back into digital signals. A cable modem is a device placed between a computer and the cable TV connection that enables communication between a computer and the local cable TV network.
MMDS (Multi-channel Multipoint Distribution Service): A digital wireless transmission service which requires line of sight between transmitter and receiving antenna, which can be up to 24 kilometres apart. Designed primarily as a wireless transmission medium for cable TV.
MPEG (Motion Picture Experts Group): A proposed International Standards Organisation (ISO) standard for digital video and audio compression for moving images. The primary application targeted during the MPEG-2 definition process was the all-digital transmission of broadcast-quality video. Deployments of the more efficient MPEG-4 are commencing for high definition television and for digital terrestrial television in markets where a service is yet to launch.
MP3: An audio compression technology that allows CD-quality sound to be downloaded over the internet. Developed in Germany as part of the MPEG specifications.
MPLS: Multi-protocol label switching
MSO (Multiple System Operator): A company that owns and operates more than one cable system.
Multiplex: A grouping of two or more digital channels within a single frequency.
Must Carry: The requirement by a local regulator for an operator to include designated channels in their line up. These will usually be the broadcast terrestrial networks.