发明名称 END-TO-END CODER/DECODER (CODEC)
摘要 A method of reducing speech delay and improving speech quality in digital transmission systems by implementing a single coder-decoder (codec) for an entire speech path from a calling party (21) to a called party (29, 52). The method is applicable to calls between mobile subscribers (21, 29) and between a mobile subscriber (21) and an H.323 client terminal (52) in a data network. After obtaining location information for the called party, an indication of a requested codec is sent from the calling party to the called party utilizing Integrated Services Data Network User Part (ISUP) or Primary Rate Interface (PRI) out-of-band signaling during call setup. If the called party supports the requested codec, a confirmation of the requested codec is sent from the called party to the calling party. A speech path is then established between the parties, and a single codec translation is performed for the entire speech path. If the called party does not support the calling party's codec, but the serving MSCs (23, 27) for both parties support the calling party's codec, the calling party's codec is utilized all the way to the called party's serving MSC. One additional codec translation is then performed in the called party's serving MSC to convert to the codec supported by the called party.
申请公布号 WO0033590(A1) 申请公布日期 2000.06.08
申请号 WO1999SE02164 申请日期 1999.11.23
申请人 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) 发明人 VO, KIM, PHUC;HASAN, SUHAIL;BERTRAND, JEAN-FRANCOIS
分类号 H04L12/28;H04L12/56;H04L29/06;H04L29/12;H04M7/00;H04W12/08;H04W36/00;H04W60/00;H04W60/06;H04W88/06;H04W88/18;(IPC1-7):H04Q7/30 主分类号 H04L12/28
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