initiated the idea of a European visual service trial. The BT trial started in 1982 and ran concurrently with the European Visual-teleconference Experiment (EVE) that was promoted by the Conference of European Postal & Telecommunications Administrations (CEPT). Both projects required standards-based video codecs, and thereby prompted the CCITT, in 1980, to form the COST 211 Specialists Group. COST was an acronym for Co-Operating for Scientific and Technological research. In 1983, the Specialists Group defined a codec-a single chassis equipped with roughly 40 circuit boards. The specification was formally adopted by the CCITT in 1984 as Recommendation H.120 (Codecs for Videoconferencing Using Primary Digital Group Transmission). It incorporated the standard PAL television signal that most Western European countries embrace. H.120 multiplexed audio, video, and signaling using the G.732 Recommendation (Characteristics of Primary PCM Multiplex Equipment Operating at 2048 Kbps). It offered interchangeable compression techniques: one optimized for normal face-to- face business meetings, and the other-that incorporated an approximately 1.5 second transmission delay-optimized for sending colored graphic images. H.120 provided for both monochrome and color operation, for multipoint switching between video codecs, and for signal encryption. Eventually, H.120 was expanded to include the SECAM broadcast standard. The new recommendation was named H.130 (Frame Structures for Use in the International Interconnection of Digital Codecs for Videoconferencing or Visual Telephony). Upon H.130's adoption, networks of standards-based publicly-available video communication studios were constructed throughout Europe. Unfortunately, the international H.130 standard fragmented the global video communication market. European codec manufacturers embraced it, but U.S. manufacturers could not deploy it as it was developed for E-1 (as opposed to T-1) networks. To address the problem, the CCITT established, in 1984, a new specialists group. Dub