G.721

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What Does G.721 Mean?

G.721 is an obsolete ITU-T Recommendation that is now superseded by standard G.726. The title of the defunct specification is “32 kbit/s adaptive differential pulse code modulation (ADPCM).” The standard was one of the ITU-T G series, which is titled “Transmission systems and media, digital systems and networks.” ADPCM is a technology used to encode digital audio.

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Techopedia Explains G.721

The International Telecommunication Union (ITU) is an arm of the United Nations that deals with information and communication technologies. ITU-T is a subset of that agency called the Telecommunication Standardization Sector. Among the many standards specified by the organization are the G Series Recommendations. As with any vibrant standards organization, these specifications are under a constant state of development and improvement.

G.721 and its neighboring recommendations are in the family of standards pertaining to the processing of digital audio signals. ADPCM converts analog signals to digital through sound sampling. ADPCM is considered a codec (coder-decoder) because of its transformation of the audio signal. The G.721 Recommendation was defined with a transmission rate of 32 kbit/s.

G.721 was established in 1984. The G.726 Recommendation superseded both G.721 and G.723 in 1990. G.726 also uses ADPCM, but it has advantages over G.721, such as the ability to transmit at multiple bit rates.

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Margaret Rouse
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Margaret jest nagradzaną technical writerką, nauczycielką i wykładowczynią. Jest znana z tego, że potrafi w prostych słowach pzybliżyć złożone pojęcia techniczne słuchaczom ze świata biznesu. Od dwudziestu lat jej definicje pojęć z dziedziny IT są publikowane przez Que w encyklopedii terminów technologicznych, a także cytowane w artykułach ukazujących się w New York Times, w magazynie Time, USA Today, ZDNet, a także w magazynach PC i Discovery. Margaret dołączyła do zespołu Techopedii w roku 2011. Margaret lubi pomagać znaleźć wspólny język specjalistom ze świata biznesu i IT. W swojej pracy, jak sama mówi, buduje mosty między tymi dwiema domenami, w ten…