utes DTV is mandatory to understanding the requirements of the next-generation network. The following sections describe the most commonly followed DTV fixed-reception standards, and Chapter 16 discusses the details of mobile TV standards. A comprehensive list of DTV deployments around the world is available at http://en.wikipedia.org/wiki/ List_of_digital_television_deployments_by_country. ATSC Standards The ATSC, an international, nonprofit organization, develops voluntary standards for DTV. It was formed in 1982 by the member organizations of the Joint Committee on InterSociety Coordination (JCIC): the Electronic Industries Association (EIA), the Institute of Electrical and Electronics Engineers (IEEE), the National Association of Broadcasters (NAB), the National Cable Television Associa- tion (NCTA), and the Society of Motion Picture and Television Engineers (SMPTE). Today, approximately 140 ATSC members represent the broadcast, broadcast equip- ment, motion picture, consumer electronics, computer, cable, satellite, and semi- conductor industries. The ATSC's DTV standards include high-definition TV (HDTV), enhanced- definition TV (EDTV), standard-definition TV (SDTV), data broadcasting, multi- channel surround-sound audio, direct-to-home satellite broadcast, and interactive television. On December 24, 1996, the U.S. FCC adopted the major elements of the ATSC DTV standard (Standard A/53). The ATSC DTV standard has since been adopted by the governments of Argentina, Canada, Mexico, and South Korea. Types of Scanning One of the biggest issues in TV standards involves how DTV images are drawn to the screen. There are two perspectives: those of the broadcast TV world and those of the computer environment. The broadcasters would rather initiate DTV with interlaced scan- ning, which is used by today's TV sets; computer companies want progressive-scanning DTV signals, similar to those used by computer monitors. The source of the conflict is dif- ferent historical bandwidth limits. Chapter 10 Next-Generation Networks O