Status Report of SMG11 at SMG#29 - 株式会社QT Report of SMG11 at SMG#29 Overview of SMG11 Work nTandem Free Operation (TFO) / TRAU n TRAU frames for AMR n AMR TFO nAMR - Narrowband

Status Report of SMG11 at SMG#29

Status Report of SMG11 at SMG#29Status Report of SMG11 at SMG#29

((TdocTdoc P-99-419) P-99-419)

Kari JärvinenChairman of SMG11

P-99-547


n Overview of SMG11 work

n Decision points


HighlightsHighlights

n AMR Narrowband characterisation phase resultspresented for information

n AMR noise suppression requirements presented forapproval (with one objection in SMG11)

n Results of AMR Wideband feasibility study andproposed WI description presented for approval

n 18 CRs to AMR, out of which 15 strategic


SMG11 meetingsSMG11 meetings

n Meetings since SMG#28n SMG11#10 (3rd – 7th May, 1999 Sophia Antipolis; hosted by ETSI)

n SMG11#11 (7th – 11th June, 1999 Tampere, Finland; hosted by Nokia)

n Meetings of ad hoc groups (AMR, SQ, TFO, AMR/NS)

n Joint meetings of SMG11 TFO and SMG2 TRAU

n SMG11 Plenary meeting statistics: ~ 40 participants, ~ 80 -100documents per meeting, 5 day meetings

n Planned meetingsn SMG11#12 (4th –8th October, 1999; host required)

n SMG11#13 (6th – 10th December, 1999; host required)

n SMG11#14 (24th – 28th January, 2000; host required)

n Joint meetings of SMG11 TFO and SMG2 TRAU


Input documents to SMG#29Input documents to SMG#29

n Status reportP-99-419 Status report of SMG11 at SMG#29

n For approvalP-99-420…424 CRs to AMR

P-99-425 GSM 02.76 v. 2.0.0 - Noise Suppression for the AMRCodec; Service Description; Stage 1

P-99-429 AMR-WB Feasibility study report v. 1.0.0 includingproposed WI description

n For informationP-99-426 Summary of the AMR Characterisation Phase Test

Results

P-99-427 Draft GSM TR 06.75 v. 1.0.0 – PerformanceCharacterisation of the GSM Adaptive Multi-Rate (AMR)Speech Codec

P-99-428 Draft GSM 06.74 v. 1.0.0 - Test sequences for theAdaptive Multi-Rate (AMR) Speech Codec


Overview of SMG11 WorkOverview of SMG11 Work

n Tandem Free Operation (TFO) / TRAUn TRAU frames for AMRn AMR TFO

n AMR - Narrowbandn Verification Phasen Characterisation Phasen VAD

n Noise suppression for AMRn Requirements for noise suppression (F for approval)n Work on test plans and selection rules

n AMR - Wideband feasibility studyn Feasibility study report and proposal for new WI (F for approval)

n Maintenance of existing specificationsn 18 CRs, out of which 15 strategic (F for approval)


TFO / TRAUTFO / TRAU

n Work consists of:

n TFO for AMR

n Development of 16 and 8 kbit/s AMR TRAU frames

n Work carried out jointly by SMG11 TFO and SMG2 TRAU

n Some open issues remain and these will be progressed jointlyby SMG11 TFO and SMG2 TRAU in dedicated meetings.

n AMR TRAU frames and TFO for AMR targeted to be completedby next SMG Plenary


AMR-NB: Verification PhaseAMR-NB: Verification Phase

n Completed except for finalising the complexity assessment ofthe channel codec to contain modifications agreed at SMG#28.

n Results will be contained in TR 06.75 (PerformanceCharacterisation of the GSM AMR speech codec) to bepresented for approval at next SMG Plenary.

n Draft version of GSM 06.74 (Test sequences for the AMRSpeech Codec) presented for information. Targeted for approvalat next SMG Plenary.


AMR-NB:AMR-NB: Characterisation Characterisation Phase Phase

n Tests completedn 7 experiments with 17 sub-experimentsn six languaguesn each experiment performed twice in two different languages.n two processing laboratoriesn eight listening laboratories

n The characterisation tests included a complete evaluation ofthe different AMR codec modesn In full- and half-rate channelsn In clean channel and under channel error conditionsn For clean speech and under different background noise conditionsn Self-tandeming and cross-tandeming, and variation in input levelsn Tests to evaluate the performances of the VAD/DTX scemes adopted

for the AMR standard (identical test conditions for the two VADoptions).



n In FR channel mode, the codec complies with the full set ofperformance requirements.

n In HR channel mode, the codec complies with the full set ofperformance requirements for both clean speech and for low channelerror conditions (down to C/I 16 dB). The codec fails to comply with therequirement in background noise in HR channel at C/I 10 dB.

n The results confirm the performances of the codec shown during theselection phase. The AMR codec actually failed a fewer number of testconditions during the characterisation phase, confirming the limitedimpact of the channel coding modification decided in SMG#28.

n Good tandeming performance:

à The two highest AMR modes do not introduce any significant degradationwhen tandemed with the other GSM speech codecs or the other AMRcodec modes.

à The other modes introduce a significantly smaller degradation than thedegradation introduced by the GSM FR or GSM HR.

n Dependency on input levels: similar behaviour to EFR.

n Key conclusions:



n With adaptation on, substantial performance improvementdemonstrated especially in FR channel mode.

n VAD/DTX operationà The in-band signaling is not impacted by the discontinuous

transmission.

à The VAD/DTX schemes do not introduce any significant qualitydegradation when activated. The same result applies to bothVAD options (ENS and Motorola).

à A direct comparison between the two VAD options across pairedexperiments reveal no significant difference between theirperformances.

Note: However, the corresponding Experiments were not designed toindicate which of the two algorithms might, in practice, be preferred bysubjects. Their primary objective was to highlight any degradation in speechquality when VAD/DTX was activated with either scheme.

n Key conclusions (continued):



n Examples: Clean cpeech in FR and HR channel

Experiment 1a - Test Results

1.0

2.0

3.0

4.0

5.0

Conditions

MOS

Sel. Requir.

AMR-FR

EFR

Sel. Requir. 4.01 4.01 4.01 3.65

AMR-FR 4.06 4.06 4.13 4.08 3.96 3.59 2.66

EFR 4.01 4.01 3.65 3.05 1.53

No Errors C/I=16 dB C/I=13 dB C/I=10 dB C/I= 7 dB C/I= 4 dB C/I= 1 dB

FR channel

Experim e nt 1b - Test Results

1.0

2.0

3.0

4.0

5.0

Condi t ions

M OS

Sel. Requir.

AMR-HR

EFR

FR

HR

Sel. Requir. 3.99 3.99 3.99 3.14 2.74 1.50

AMR-HR 4.11 4.04 3.96 3.72 3.38 3.10 2.00

EFR 4.21 4.21 3.74 3.34 1.58

FR 3.50 3.50 3.14 2.74 1.50

HR 3.35 3.24 2.80 1.92

No Errors C/I=19 dB C/I=16 dB C/I=13 dB C/I=10 dB C/I= 7 dB C/I= 4 dB

HR channel



n Examples: Quality under background noise (car noise, 15 dBSNR) in FR and HR channel

FR channel HR channel

Experiment 3e - Test Results

1.0

2.0

3.0

4.0

5.0

No Errors C/I=19 dB C/I=16 dB C/I=13 dB C/I=10 dB C/I= 7 dB C/I= 4 dB

Condi t ions

DM OS

Sel. Requir.

AMR-HR

EFR

FR

HR

Experiment 3b - Test Results

1.0

2.0

3.0

4.0

5.0

No Errors C/I=16 dB C/I=13 dB C/I=10 dB C/I= 7 dB C/I= 4 dB C/I= 1 dB

Condit ions

DM OS

Sel. Requir.

AMR-FR

EFR

FR

G.729


AMR-NB: Voice Activity DetectorAMR-NB: Voice Activity Detector

n SMG#28 approved GSM 06.94 in Tdoc SMG P-99-132 (VAD for AMRspeech traffic channels; General description). The VAD consists oftwo algorithms and the MS and BSS manufacturers are free to choosewhich of the two VAD options to implement.

à Option 1: ENS VADà Option 2: Motorola VAD

n SMG#28 noted that integration of Motorola VAD to the AMR speechcodec needs work, and that changes to the textual part of GSM 06.94might be needed. SMG#28 requested all changes to GSM 06.94 dueto this process to be forwarded by SMG11 as CRs to SMG#29.

n SMG11 noted at SMG#28 that there is no universally recognisedmethodology to select a VAD algorithm but that SMG11 willinvestigate possibilities to reduce the number of VAD algorithmoptions to one. SMG#28 endorsed this intention of SMG11 to limit ofthe two VAD algorithms to one.

n Background (at SMG#28)



n As requested, SMG11 is bringing CRs to SMG#29 for approval aligningthe textual part of VAD specifications to the Motorola C-code.

n SMG11 feels that it would be desirable to limit the number of VADoptions into one.

n However, based on the characterisation test results and othercomplementing information, SMG11 is not able to make a consensusdecision on which of the two options should be dropped.

n SMG11 has not planned further testing to separate the two VAD optionsin terms of speech quality

à for these; performance requirements would need to be agreed,testplans drafted, subjective tests performed and results analysed.

à the process would take considerable effort and time

n Nevertheless, SMG11 has agreed on a number of issues between thetwo VAD options:

à Speech quality

à Voice activity

à Implementation complexity



1) Quality: Based on characterisation test results and other informationavailable to SMG11, the overall quality of both VAD options is apparentlysimilar.

n It is noted however that the tests were not specifically designed for selectionpurposes between the VAD options. Also, no correlation with voice activitywas presented for the tested samples.

2) Voice activity: The average voice activity factor of VAD option 1 is lowerthan for option 2 (52 vs. 56 % using the EFR DTX characterisationmaterial).

n It is noted however that a number of factors impact the voice activity,including speaker characteristics, background noise, signal level etc. Thismeans that in some conditions the voice activity factor of VAD option 2 islower.

3) Complexity: The complexities for VAD options 1 and 2 are shown inTable 1. The wMOPS in Table 1 is the worst-case value computed using alarge amount of data including noisy speech, clean speech, and music.

SMG11 agreements considering the two VAD options



Option 1 Option 2RAM w ords 66 99ROMWords

Code 365 327

Tables - 342Total 365 669

WMOPS 0.358 1.045

T a b le 1 . V A D c o m p le x i t y c o m p a r is o n


Noise suppression for AMRNoise suppression for AMR

n The requirements, design constraints, selection rules and test plans havebeen progressed within SMG11.

n Service Description (Stage 1) GMS 02.76, containing requirements fornoise suppression, is presented for approval with one objection in SMG11.The objection is from BT Cellnet on two issues in the requirements:n 1) the speech path delay requirement of 7 ms algorithmic delay (defined in

section 4.6.2); for which they would like to have had a lower value (6 ms asthe total propagation delay), and

n 2) the amount of noise suppression; for which they would have like to set arequirement and the requirement to be assessed using a DelSM acoustic test.

n Six proponents have given firm commitment for participation and funding(up to 50 kEURO each) with proviso regarding approval of therequirements at SMG#29.

n The schedule for reporting selection results and bringing specifications forSMG approval is revised to SMG#31 (from SMG#30) to allow sufficienttime for finalisation of test plan and carrying out analysis of results.


AMR -AMR - Wideband Wideband: Feasibility Study: Feasibility Study

n SMG11 has conducted a study into the feasibility of AMR wideband (AMR-WB) speech codec [audio bandwidth up to 7 kHz]

n The AMR wideband service option was considered within SMG11 alreadyduring the AMR narrowband feasibility study and development phasesduring 1997-1998.

n SMG meeting #23 (October 1997) decided that the AMR narrowbandprogramme should not be delayed for the sake of introducing a widebandmode and that feasibility assessment with regard to wideband should becompleted as soon as possible.

n Wideband could then be added to AMR as a later option, as optionalmode(s), according to the outcome of the feasibility assessment.

n Due to intensive AMR narrowband development and standardisation, themain part of the wideband feasibility study has been carried out after SMGmeeting #27 (October 1998).



n Benefits of wideband coding

n Current GSM codecs (FR, HR, EFR and AMR) are narrowbandcodecs and operate for audio bandwidth limited below 3.4 kHz.

n The introduction of a wideband speech service (audio bandwidthextended to 7 kHz) will provide substantial improvement in voicequality especially in terms of increased naturalness in voice.

n Wideband coding would bring speech quality exceeding that of(narrowband) wireline quality to GSM.



n Goals of AMR-WB development

n Develop wideband speech coding targeted for existing and evolvedGSM systems as well as other related mobile systems, such as the3GPP system. Primary development focus will be on the GSM full-rate traffic channel.

n AMR-WB will provide

à In medium and low error conditions; improved speech quality(exceeding G.711 PCM wireline quality) through theintroduction of the wider audio bandwidth (7kHz)

à A wideband speech service providing a channel robustnesssimilar to that of the existing narrowband GSM FR and GSMEFR speech coders when used in GSM.

à A wideband speech service which will be applicable to existingand evolved GSM systems as well other mobile systems, thusenabling efficient wideband speech service interoperation

à Added flexibility to AMR, which can be used to tailor the speechservices to specific operator need



n Performance

n The feasibility study has focused on the possibility to offer a highquality wideband service using the GSM FR traffic channel.

n AMR-WB is intended to be used in medium and low error-ratechannels. In GSM FR single slot channel, the AMR-WB coder willprovide:à Quality exceeding G.711 PCM wireline quality for medium and

low error rates (down to 13 dB C/I) with quality for low errorconditions comparable to 56 kbit/s wideband speech in ISDN.

à Channel robustness, i.e. performance at lower C/I, similar to thatof the existing narrowband GSM FR and GSM EFR speechcoders

n If 16 kbit/s A-ter submultiplexing is used, thus further limiting thehighest source coder rate, it is still likely that the quality for speech willbe as good as G.722 at 48 kbit/s. (At least one of the WB-AMRmodes shall be compatible with GSM 16 kbit/s submultiplexing.)



n At a relatively late stage, applications using higher bit-rate mobilechannels were added to the study. GSM/EDGE phase II as well as3G systems are now included in the scope of the activity.

à Using higher rate channels, it is possible to make use of AMR-WBmodes with rates exceeding 22.8 kbit/s, thus achieving an even higherlevel of quality.

n The performance requirements and design constraints for thesefuture channels will be complemented during the AMR-WBdevelopment phase.

n For the development of wideband coding for 3G channels, a closecollaboration with the relevant 3G-groups (3GPP TSG-S4) can andshould be established.

à S4 has noted the SMG11 AMR-WB feasibility study, and that theobjectives are in line with the 3G objectives.

à S4 has agreed to prepare in their next meeting a set of performancerequirements for 3G channels and submit this to SMG11 as an input toa joint project development.



n To achieve the performance goals the AMR-WB coder should bea multi-rate wideband speech coder utilising channel qualitybased mode adaptation similar to the AMR narrowband.

Risk areas/considerations

n Codec performance – good wideband performance in poorchannel conditions needs to be verified

n Architectural and network issues – the signalling for theestablishment of a wideband call needs to be studied anddeveloped

n A wideband call can be established only when both ends havewideband capable terminals. This requires that wideband audioparts are introduced in terminals, and is likely to imply that theuse of AMR-WB will, at least initially, be restricted to MS-to-MScalls.



n Initiate a programme to develop, test, select and specify AMRwideband (AMR-WB) together with related features such asVAD/DTX.

n An acceptable and workable timeplan should be agreed by SMG11(and SMG1/SMG2/SMG3/SMG12) as soon as possible afterSMG#29 with the priority of targeting approval of AMR-WB codec byend of year 2000 for GSM Release 2000.

n Approve proposed Work Item description for AMR-WB

Based on the feasibility study results, SMG11 believes thatAMR-WB is feasible and recommends SMG the following:


Maintenance of specificationsMaintenance of specifications

n 18 Change Requests

All for AMR, for 06-series specifications GSM 06.73, 06.90,06.92, 06.93 and 06.94

n 15 strategic CRs

n 3 non-starategic CRs


END OF THE GENERAL PART OF SMG11 REPORT


Decision points and guidanceDecision points and guidance

1) GSM 02.76 ( Noise Suppression for the AMR Codec, ServiceDescription, Stage 1 ) with one objection in SMG11 (BT Cellnet)

n in Tdoc P-99-425

2) AMR-WB feasibility study and Work Item descriptionn in Tdoc P-99-429 (WI description in Annex F)

3) 18 CRs, out of which 15 are strategicn in Tdoc P-99-420 (for GSM 06.73)n in Tdoc P-99-421 (for GSM 06.90)n in Tdoc P-99-422 (for GSM 06.92)n in Tdoc P-99-423 (for GSM 06.93)n in Tdoc P-99-424 (for GSM 06.94)

The following issues are presented to SMG for approval:


List ofList of CRs CRs

n in Tdoc P-99-420 (for GSM 06.73 "ANSI-C code for the GSM AMR speechcodec"):

TDoc SPEC CR PHASE

VERS SUBJECT CAT PageB-99-131 06.90 A001 R98 7.0.0 Introduction of codec homing procedure F 2B-99-135 06.90 A002 R98 7.0.0 Description of instability protection in AMR F 6

Tdoc SMG11

SPEC CR PHASE

VERS SUBJECT CAT Page

130/99 06.73 A001 R98 7.0.0 Introduction of codec homing procedure B 2140/99 06.73 A002 R98 7.0.0 Correction to Bit Exact Implementation of Gain Calculation in Adaptive

Gain Control (agc) for 12.2 and 7.4 kbit/s ModeF 12

141/99 06.73 A003 R98 7.0.0 Correction to the bit stream output file format used by the speechencoder

F 15142/98 06.73 A004 R98 7.0.0 Correction to Bit Exact Implementation of Levinson Algorithm for 12.2

kbit/s modeF 17

143/99 06.73 A005 R98 7.0.0 Correction to LSP vector initialization F 19179/99 06.73 A006 R98 7.0.0 Documentation of encoder/decoder file formats D 22134/99 06.73 A007 R98 7.0.0 Correction to list of decoder static variables F 24173/99 06.73 A008 R98 7.0.0 Correction to DTX decoder LSF history buffer update F 27174/99 06.73 A009 R98 7.0.0 Correction to bit exact implementation of decoder synthesis filter

instability protectionF 29

208/99 06.73 A010 R98 7.0.0 AMR VAD/DTX Description F 31

n in Tdoc P-99-421 (for GSM 06.90 "AMR speech transcoding"):


List ofList of CRs CRs

Tdoc SMG11

SPEC CR PHASE

VERS SUBJECT CAT Page

136/99 06.92 A001 R98 7.0.0 Correction of averaging formula

TDoc SPEC CR PHASE

VERS SUBJECT CAT PageB-99-139 06.93 A001 R98 7.0.0 Changed SID update rate for AMR codec on TCH/AFS C 2B-99-137 06.93 A002 R98 7.0.0 Specification of handling of SPARE and NO_DATA RX_TYPEs F 4

TDoc SPEC CR PHASE

VERS SUBJECT CAT PageB-99-205 06.94 A001 R98 7.0.0 AMR VAD/DTX - Merging of both AMR VAD options into one document D 2B-99-206 06.94 A002 R98 7.0.0 AMR VAD/DTX Description - Alignment of 06.94 with the ANSI C code F 40B-99-207 06.94 A003 R98 7.0.0 AMR VAD/DTX Description - Alignment of 06.94 with approved C Code F 50

n in Tdoc P-99-422 (for GSM 06.92 "Comfort noise aspects for AMR speechtraffic channels"):

n in Tdoc P-99-423 (for GSM 06.93 "DTX for AMR speech traffic channels"):

n in Tdoc P-99-424 (for GSM 06.94 "VAD for AMR speech traffic channels"):


Decision points and guidanceDecision points and guidance

n AMR VAD

n May the two AMR VAD options be sustained?

n Should SMG11 proceed into futher investigations of limiting the

number of options to one?


END OF PRESENTATION

Documents

Status Report of SMG11 at SMG#29 - 株式会社QT Report of SMG11 at SMG#29 Overview of SMG11 Work nTandem Free Operation (TFO) / TRAU n TRAU frames for AMR n AMR TFO nAMR - Narrowband