IS-641

TIA/EIA standard IS-641 is a speech coding standard released in 1996^[1] and used in some computer and telecommunications networks in the United States. The main usage was in the U.S. TDMA networks defined by IS-136.^[2][3] The bit rate of the speech codec is 7.4 kbit/s.^[1] This codec is the same as the 7.4 kbit/s mode in the AMR speech codec.^{[citation needed]} The standard was superseded^{[citation needed]} by TIA/EIA-136-410's release in 1999.^[4]