IS-641
Encyclopedia
TIA
/EIA
standard IS-641 is a speech coding
standard used in some computer
and telecommunications network
s in the U.S.A. Main usage was in the U.S. TDMA
networks defined by IS-136. The bit rate of the speech codec
is 7.4 kbit/s. This codec is the same as the 7.4 kbit/s mode in the AMR
speech codec. The standard has been superseded by TIA/EIA-136-410.
Telecommunications Industry Association
The Telecommunications Industry Association is accredited by the American National Standards Institute to develop voluntary, consensus-based industry standards for a wide variety of ICT products, and currently represents nearly 400 companies...
/EIA
Electronic Industries Alliance
The Electronic Industries Alliance was a standards and trade organization composed as an alliance of trade associations for electronics manufacturers in the United States. They developed standards to ensure the equipment of different manufacturers was compatible and interchangeable...
standard IS-641 is a speech coding
Speech coding
Speech coding is the application of data compression of digital audio signals containing speech. Speech coding uses speech-specific parameter estimation using audio signal processing techniques to model the speech signal, combined with generic data compression algorithms to represent the resulting...
standard used in some computer
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
and telecommunications network
Telecommunications network
A telecommunications network is a collection of terminals, links and nodes which connect together to enable telecommunication between users of the terminals. Networks may use circuit switching or message switching. Each terminal in the network must have a unique address so messages or connections...
s in the U.S.A. Main usage was in the U.S. TDMA
Time division multiple access
Time division multiple access is a channel access method for shared medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This...
networks defined by IS-136. The bit rate of the speech codec
Codec
A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
is 7.4 kbit/s. This codec is the same as the 7.4 kbit/s mode in the AMR
Adaptive Multi-Rate
The Adaptive Multi-Rate audio codec is a patented audio data compression scheme optimized for speech coding. AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM and UMTS...
speech codec. The standard has been superseded by TIA/EIA-136-410.