CATV

CATV, short for Community Antenna Television, is a system for distributing television signals to multiple households through coaxial cables. It originated in the United States in the late 1940s to improve reception in areas where individual antennas were impractical, such as mountains or dense urban environments. Signals are collected at a central location, or headend, and redistributed over a shared network to subscribers.

Over time, CATV expanded from a few channels to many, with improved amplification, better frequency allocation, and more sophisticated modulation. The term has persisted even as the underlying technology has evolved; today it generally refers to large-scale cable television and related services rather than a single local community antenna arrangement.

Architecture and technology: A headend receives local channels, off-air signals from distant stations, and sometimes local origination content. These signals are encoded and modulated for transmission over trunk and feeder cables to neighborhoods. From the feeder, drop cables deliver the signal to individual homes. Modern CATV networks commonly use hybrid fiber-coax (HFC), with fiber from the headend to distribution nodes and coax from nodes to subscribers, increasing capacity and reducing loss.

Digital transition and services: Most CATV systems now carry digital channels and use quadrature amplitude modulation (QAM) for video over coax. For data, they employ the DOCSIS standard to provide broadband Internet and IP services on the same plant. Set-top boxes enable channel decoding, on-demand content, and other interactive features; many operators offer bundled video, data, and voice services.

Impact: CATV networks have significantly shaped television distribution, enabling multi-channel access and integrated broadband. The market faces competition from satellite and online streaming, but cable remains a major delivery platform in many regions.