ober 1992. It begins with a rather low image resolution; about 240 lines by 352 pixels per line. This image is compressed at 30 frames per second. It provides a digital image transfer rate up to about 1.5 Mbps and compression rates of about 100:1. The MPEG-1 specification consists of four parts: system, video, audio, and compliance testing. MPEG-2 The MPEG-2 is Committee Draft 13818, and can be found in documents MPEG93/N601, N602 and N603. This draft was completed in November 1993. Its formal name is "Generic Coding of Moving Pictures and Associated Audio." MPEG-2 is targeted for use with high-bandwidth applications aimed at digital television broadcasts. It specifies 720-by-408 pixel resolution at 60 fields-per-second with data transfer rates that range from 500 Kbps to more than 2 Mbps. Video Communication: the Whole Picture MPEG-4 "Very Low Bitrate Audio-Visual Coding." An 11/94 Call for Proposals by ISO/IEC resulted in a Working Draft specification in 11/96. MS-DOS A computer operating system developed by Microsoft and originally aimed at the IBM PC. multicasting Conferencing applications that typically use packet- switched transmission to broadcast a signal that can be received by multiple recipients, all of whom are listening on a single multicasting address. multi-mode fiber Optical fiber with a central core of a diameter sufficient to permit light-pulses to zig-zag from side to side as well as to travel straight down the middle of the core. Step-indexed fibers have a sudden change of refractive index where cladding meets core. Signals are reflected back at this boundary. Graded index fibers have a gradual change of refractive index with radial distance from the center of the core, pulses are refracted back by this change. multimedia According to the Defense Information Systems Agency: "Two or more media types (audio, video, imagery, text, and data) electronically manipulated, integrated, and reconstructed in synchrony." Generally, multimedia refers to these media in a digital format for it is the digitiz