1 © NOKIA GPP2 Wideband Codec Presentation Interoperable Wideband Speech Coder for CDMA2000 and WCDMA Systems W-VRM: Wideband Variable-Rate Multi-Mode Speech Codec for 3GPP2 Mitch Tseng, Ph.D. Nokia January 24, 2002

2 © NOKIA GPP2 Wideband Codec Presentation Topics Evolution of Wireless Speech Coders Wideband Speech AMR-WB: Wideband Speech in 3GPP & ITU W-VRM: Wideband Speech in 3GPP2 Audio Demonstration

3 © NOKIA GPP2 Wideband Codec Presentation ? EVOLUTION OF WIRELESS SPEECH CODECS IS-96A Rate-Set I 1993 FR 13 kbps GPP2: Variable Rate Speech Coding 3GPP: Fixed Rate Speech Coding With VAD/DTX QCELP13 Rate-Set II 1994 EVRC Rate-Set I 1995 SMV Multimode Rate-Set I 2001 HR 5.6 kbps 1995 EFR 12.2 kbps 1996 AMR-NB Multi-Rate GPP/ITU AMR-WB Multi-Rate W-VRM Rate-Set II Common Mode of Operation (Interoperable Mode)

4 © NOKIA GPP2 Wideband Codec Presentation WIDEBAND SPEECH: BACKGROUND MATERIAL

5 © NOKIA GPP2 Wideband Codec Presentation WHAT IS WIDEBAND SPEECH? The status quo narrowband speech codecs including PCM provide a voice bandwidth of 300 Hz~3.4 kHz. A wideband codec operates at a 16 kHz sampling rate and provides a voice bandwidth of 50 Hz~7 kHz. More bandwidth, both at the upper end and the lower end. 7 kHz 3.4 kHz Status Quo (PCM) Wideband 50 Hz 300 Hz

6 © NOKIA GPP2 Wideband Codec Presentation WHY WIDEBAND SPEECH? Current mobile systems and fixed line telephone networks offer only narrowband speech services ( ~ Hz) Recent advances in speech coding have made wideband coding feasible in bit-rates applicable to mobile systems 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 Narrowband Speech Hz Wideband Speech Hz

7 © NOKIA GPP2 Wideband Codec Presentation WHY WIDEBAND SPEECH NOW? Competitive Issues A voice quality that is superior to the status quo and will prevail in the future All narrowband codecs today provide near-landline quality (Squeezing the limit of PCM) Wideband codec voice quality far exceeds landline quality Challenge from Voice over IP Worldwide Wideband Codec Efforts ITU G.722 for Multimedia Applications 3GPP – Wideband AMR, multi-rate, each rate fixed with VAD/DTX ITU-G.722.1: ITU Wideband Codec for Voice and Multimedia 3GPP AMR-WB = ITU-G Our Objective To standardize a Multi-mode, Variable Rate Bandwidth-Efficient Wideband Codec that fits in the CDMA2000 Rate Set 2 environment and can interoperate with other Wideband Codecs – ITU, 3GPP

8 © NOKIA GPP2 Wideband Codec Presentation 3GPP2 CODECS: QUALITY AND CAPACITY Increasing ADR Increasing Voice Quality QCELP13 SMV Mode 0 EVRC SMV Mode 3 SMV Mode 2 SMV Mode 1 Rate-Set IIRate-Set I W-VRM Mode 2 W-VRM Mode 3 W-VRM Mode 1 W-VRM Mode 0

9 © NOKIA GPP2 Wideband Codec Presentation AMR-WB: WIDEBAND SPEECH FOR 3GPP AND ITU

10 © NOKIA GPP2 Wideband Codec Presentation THE AMR WIDEBAND CODEC STANDARD 3GPP approved the Adaptive Multi Rate WideBand (AMR-WB) codec standard in March 2001 In July 2001 AMR-WB was adopted as the new ITU-T wideband standard First codec to be used both for wireless and wireline services: No transcoding between wireless and wireline systems -> no loss of quality in the interconnection Simplifies the implementation of global wideband speech services

11 © NOKIA GPP2 Wideband Codec Presentation W-VRM: WIDEBAND VARIABLE-RATE MULTI-MODE SPEECH CODEC FOR 3GPP2

12 © NOKIA GPP2 Wideband Codec Presentation W-VRM FOR 3GPP2: OVERVIEW Proposed Codec is Ideal for 3GPP2 Applications: Less Complex than SMV (Lower Complexity and Lower Memory) Same Algorithmic Delay as SMV with 20ms frame structure Multi-mode, Variable Rate Codec functionally similar to SMV Variable Rate to Provide Better Bandwidth Efficiency Comparable Voice Quality with ITU/3GPP Wideband Codec Provides Superb End-to-End Voice Quality at Rate Set 2 and at QCELP13 Capacity Suitable for 3GPP2 TFO and VoIP Applications Interoperable with new ITU/3GPP Wideband Codec A Multi-mode Codec Functionally Similar to SMV

13 © NOKIA GPP2 Wideband Codec Presentation W-VRM: PROPOSED REQUIREMENTS Input sampling 16 kHz and audio bandwidth Hz Frame size 20 ms Multi-mode and variable-rate wideband coding system Full compliance with IS-95/cdma2000 rate-set II in all modes No physical layer changes required. Four modes of operation Mode 0: Worldwide Interoperable Mode Mode 1: Premium mode (Quality) Mode 2: Standard mode (IS-733 ADR equivalence) Mode 3: Economy mode (Capacity) Algorithmic delay less than 35 ms Computational complexity less than SMV

14 © NOKIA GPP2 Wideband Codec Presentation W-VRM Interoperable Mode Mode 0 (12.65kbps) Mode 0 (12.65kbps) Others Other Modes Other Modes WB-VRM WB-AMR WCDMA CDMA2000 Interoperable

15 © NOKIA GPP2 Wideband Codec Presentation W-VRM: APPLICATIONS Tandem-Free Mobile-to-Mobile calls Wideband speech codec can be used for transparent-network mobile-to-mobile calls. Wideband telephony over packet networks (Mobile-to-IP) The intrinsic bandlimited nature of the current PSTN and wireless systems can be overcome through the use of IP networks. Teleconferencing Wideband coding can further improve the quality of service for wireless/wireline teleconferencing systems beyond of what can be achieved through the use of narrowband codecs. Wireless Multimedia There are a multitude of wireless multimedia applications such as streaming and broadcasting that can benefit from the advantages offered by wideband speech coding. Rate Set 2, Tandem Free and IP are the Keys

16 © NOKIA GPP2 Wideband Codec Presentation W-VRM: STANDARDIZATION ASPECTS Proposed Schedule 1Q 2002: Approval of the work item. Definition of the high-level requirements. 2Q 2002: Final definition of the requirements and approval of the test plan for the wideband speech codec. 3Q 2002: Characterization and standardization of the wideband codec and completion of the baseline specifications. Recommend TSG-S to approve the work item and Stage 1 so that the Voice Services group (TSG-C WG1 SWG1) can start the work ASAP.

17 © NOKIA GPP2 Wideband Codec Presentation SUMMARY 3GPP and ITU Have Standardized a Common Wideband Speech Codec wireless and wireline applications easily the best as the competition proved 3GPP2 Has the Opportunity to “Harmonize” via Our Own Wideband Speech Codec with a Common Mode of Operation mode = W-VRM Mode 0 other modes use variable-rate coding to further enhance system capacity Work Item Initially Supported by Bell Mobility, Sprint PCS, SK Telecom, KT Freetel, ALLTEL and Nokia. Building A New Harmonized Wideband Speech Codec