TIA/ EIA standard IS-641 is a

speech coding Speech coding is an application of data compression to 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 da ...

standard released in 1996 and used in some

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

and

telecommunications network A telecommunications network is a group of Node (networking), nodes interconnected by telecommunications links that are used to exchange messages between the nodes. The links may use a variety of technologies based on the methodologies of circuit ...

s in the United States. The main usage was in the U.S. TDMA networks defined by IS-136. The

bit rate In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction ...

of the speech

codec A codec is a computer hardware or software component that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder o ...

is 7.4 kbit/s. This codec is the same as the 7.4 kbit/s mode in the AMR speech codec. The standard was superseded by TIA/EIA-136-410's release in 1999.

References

Speech codecs Mobile telecommunications standards {{Telecomm-stub