H.324 is an

ITU-T The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Co ...

recommendation for

voice The human voice consists of sound made by a human being using the vocal tract, including talking, singing, laughing, crying, screaming, shouting, humming or yelling. The human voice frequency is specifically a part of human sound producti ...

video Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) sy ...

and

data In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpret ...

transmission over regular

analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is encoded in a continuous variable ** Analog device, an apparatus that operates on analog signals *** Analog electronics, circuits which use analog ...

phone A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into ele ...

lines. It uses a regular 33,600 bit/s

modem A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more c ...

for transmission, the

H.263 H.263 is a video compression standard originally designed as a low-bit-rate compressed format for videotelephony. It was standardized by the ITU-T Video Coding Experts Group (VCEG) in a project ending in 1995/1996. It is a member of the H.26x fam ...

codec for video

encoding In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication ...

and

G.723.1 G.723.1 is an audio codec for voice that compresses voice audio in frames. An algorithmic look-ahead of duration means that total algorithmic delay is . Its official name is ''Dual rate speech coder for multimedia communications transmitting at ...

for audio. H.324 standard is formally known as ''Terminal for low bit-rate multimedia communication''. H.324 covers the technical requirements for very low bit-rate multimedia telephone terminals operating over the

General Switched Telephone Network The public switched telephone network (PSTN) provides infrastructure and services for public telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local teleph ...

(GSTN). H.324 terminals provide real-time video, audio, or data, or any combination, between two multimedia telephone terminals over a GSTN voice band network connection. H.324 terminals offering audio communication shall support the G.723.1 audio codec. H.324 terminals offering video communication shall support the H.263 and H.261 video codecs. G.722.1 may be used for wideband audio applications. Annex G of H.324 specification defines usage of ISO/IEC 14496-1 (

MPEG-4 MPEG-4 is a group of international standards for the compression of digital audio and visual data, multimedia systems, and file storage formats. It was originally introduced in late 1998 as a group of audio and video coding formats and related t ...

Systems) generic capabilities in H.324 terminals. H.324/I terminals shall support interoperation with voice telephones using

G.711 G.711 is a narrowband audio codec originally designed for use in telephony that provides toll-quality audio at 64 kbit/s. G.711 passes audio signals in the range of 300–3400 Hz and samples them at the rate of 8,000 samples per second ...

speech coding, if the connected network supports transmission and reception of G.711. Other modes such as G.722 audio may optionally be supported as well.ITU-T (2005-09) (PDF
H.324 : Terminal for low bit-rate multimedia communication
Retrieved on 2009-07-21 H.324 was adapted by 3GPP to form

3G-324M 3G-324M is the 3GPP umbrella protocol for video telephony in 3G mobile networks. The 3G-324M protocol operates over an established circuit switched connection between two communicating peers. 3G-324M is an umbrella specification to enable conv ...

. It is for example used in the Vialta Beamer BM-80 Phone Video Station, the MINX system from Datapoint Corporation, and in several other

videophones Videotelephony, also known as videoconferencing and video teleconferencing, is the two-way or multipoint reception and transmission of audio and video signals by people in different locations for real time communication.McGraw-Hill Concise Ency ...

References

External links

ITU-T Recommendation H.324 : Terminal for low bit-rate multimedia communication

Videotelephony ITU-T recommendations ITU-T H Series Recommendations {{telephony-stub

See also

References

External links