videophone

A videophone is a telecommunications device that enables real-time two-way audio and video communication between two or more locations. It typically combines a camera, display screen, microphone, speaker, and network connection in a single unit or integrated into a computer or smartphone. Videophones can operate over various networks, including legacy telephone networks, ISDN, and the Internet.

The concept dates to the 1960s. The Bell System introduced the Picturephone and demonstrated it publicly in that era; commercial pilots followed in limited cities, but hardware and bandwidth constraints limited adoption. In the 1980s and 1990s, ISDN-based videophones and early video conferencing systems popularized consumer and business use. With the rise of IP networks and standards like H.323 and later SIP and H.264, videophones evolved into software-driven video calling on computers and mobile devices.

Technology and standards. Key components include a camera, microphone, display, processing unit, and network interface. Compression codecs such as H.261, H.263, H.264 enable efficient video transfer; signaling standards like H.323 and SIP define control mechanisms for establishing calls. Early videophones used dedicated lines; later systems use general-purpose networks, including broadband and mobile data.

Usage and impact. Today, the term is often used interchangeably with video calling or videoconferencing. Modern smartphones and apps provide mobile video calling, while dedicated videophone hardware remains in some business, healthcare, or home-security contexts. The technology has contributed to remote work, telemedicine, and long-distance communication, although bandwidth, latency, and privacy considerations remain important.