h the impedance of cables. Discrete Cosine Transform DCT. A pixel-block based process of formatting video data in which it is converted from a three- dimensional form to a two-dimensional form suitable for further compression. In the process, the average luminance of each block or tile is evaluated using the DC coefficient. Used in the ITU-T's H.261 and H.263 videoconferencing compression standards and the ISO/ITU-T's MPEG and JPEG image compression recommendations. Discrete Wavelet DWT. Based on same principles as DCT, this method Transform segregates the spectrum into waves of different lengths and then processes all frequencies to retain the image's sharp lines, which are partially lost in the Video Communication: the Whole Picture DCT process. distance learning The incorporation of video and audio technologies into the educational process SO that students can attend classes and training sessions in a location distant from that where the course is being presented. dithering In color mapping, dithering is a method of representing a hue, not available in the color map, by intermingling the pixels of two colors that are available and letting the eye-brain team average them together into a single perceived median color. Divestiture In early 1982, AT&T signed a Consent Decree and thereby agreed to spin off the 22 local Bell Operating Companies (BOCs). These were grouped into seven Regional Bell Holding Companies that managed their business, coordinated their efforts, and provided strategic direction. Restrictions were placed on both the BOCs and AT&T. The US Department of Justice stripped AT&T of the Bell name (except in their Bell Labs operation), the authority to carry local traffic, and the option to discriminate in favor of their former holdings. BOCs were awarded Yellow Pages publishing and allowed to supply local franchised- monopoly services, but were not allowed to provide information services or to manufacture equipment. They could carry calls only within local access and transport areas (LATAs). This agre