rovided to control access to the channel and to minimize information "collisions" and distortions caused by more than one terminal transmitting at the same time. Different types of LANs use different access methods to avoid collisions. Baseband LANs present a challenge to companies that wish to put video over their networks because video requires isochronous service (i.e., the delivery of information is smoothly timed). Baseline Sequential JPEG The most popular of the JPEG modes. It employs the lossy DCT to compress image data as well as lossless processes based on DPCM. The "baseline" system represents a minimum capability that must be present in all Sequential JPEG decoder systems. In this mode, image components are compressed either individually, or in groups. A single scan pass completely codes a component or group of components. If groups of components are coded, the data is interleaved; it allows color images to be Glossary of Terms compressed and decompressed with a minimum of buffering. Basic Rate ISDN See BRI. British Broadcasting Corporation, formed in 1923 as the monopoly radio and later television, broadcaster in the United Kingdom. Also used as an abbreviation of background color cancellation. Bell Operating Company Any of the 22 regulated telephone companies that were "spun off" from AT&T during divestiture. The BOCs (or regional bell operating companies-RBOC) are grouped into RBHCs-Regional Bell Holding Companies such as Nynex, BellSouth and others. Bellcore An abbreviation for Bell Communications Research. Bellcore is a resource for software engineering and consulting that created many public network architectures for the Regional Bell Holding Companies (RBHCs) over the years. Formed to take the place of Bell Labs, which, after divestiture, severed all formal ties with the BOCs, it was owned by all seven RBHCs until the fall of 1996. At that time the RBHCs sold it to Science Applications International Corporation (SAIC), a company that specializes in government consulting for the Defense Departmen