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General aspects of standardization for public NGN wideband speech codec. Wideband Speech 50-7000 Hz. Narrowband Speech 300-3400 Hz. Why wideband codec for NGN?. Current wireless systems and wireline telephone networks offer only narrowband speech services (300 ~ 3400 Hz)
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General aspects of standardizationfor public NGN wideband speech codec GSC-8, OTTAWA
Wideband Speech 50-7000 Hz Narrowband Speech 300-3400 Hz Why wideband codec for NGN? • Current wireless systems and wireline telephone networks offer only narrowband speech services (300 ~ 3400 Hz) • Recent advances in speech coding have made wideband coding feasible in bit-rates applicable to mobile systems in first • Wideband provides superior quality over narrowband telephony • Increased naturalness (low end) • Better fricative differentiation (high end) higher intelligibility • Increased presence feeling of transparent communication • Increased comfort • Easier speaker recognition GSC-8, OTTAWA
EVRC Rate-Set I Status of speech codec standardization NGN:? 3GPP: Fixed Rate Speech Coding With VAD/DTX 3GPP2: Variable Rate Speech Coding Wireline & Wireless Convergence ? ? 3GPP/ITU AMR-WB/G.722.2 Multi-Rate 3GPP2 W.B Rate-Set II 2000- 2001 2003 Ongoing AMR-NB Multi-Rate SMV Multi-mode Rate-Set I 1999 2001 EFR 12.2 kbps 1996 1995 HR 5.6 kbps 1995 QCELP13 Rate-Set II 1994 FR 13 kbps 1989 GSC-8, OTTAWA
Research Trends in NGN • Study items about the NGN in the world • NGN 2004 Project of ITU-T • SG13, and SG11, SSG • The research on NGN in ETSI and NGN action project of NGN (NGNI) GSC-8, OTTAWA
Wideband speech codec & NGN • Wideband codec operates only at a 16~20+ Kbpsrate and provides a voice bandwidth of 50 Hz~7 kHz+ • NGN is all packet network providing • Superior service quality for telephony is one of killer application • Reliable and constant service quality • Various service level agreements: billing vs. free, p-p vs. p-mp • Interoperability with narrowband speech Narrowband Wideband 50 Hz 300 Hz 3.4 kHz 7 kHz+ GSC-8, OTTAWA
Standardization Issues – Status • Codec Quality • Lack of consistency of service quality • Lack of various SLA • Codec delay, bandwidth & Complexity • Current: Fixed delay, bandwidth & Complexity • Future: Scalable codec delay, bandwidth, and complexity according to service grade • Other Issues • Various telephony service types: lack of point-to-multi-point service • Language differences for validation of codec performance GSC-8, OTTAWA
Standardization Issues – Required • Superior and constant speech quality • Speech quality considering service consistency • Considering the characteristics of packet network • Scalable codec architecture providing • Current activity: ITU-T SG16 WP3 Q9/16: Embedded Variable Codec • Scalable codec delay, bandwidth, and complexity according to service grade • Various service types, SLA • Other Issues • Time-to-market: NGN activity plan of telcos GSC-8, OTTAWA