ITU G.164:1988
ITU G.164:1988 Echo Suppressors
Table of Contents
1General1.1Application
1.2Designfeatures
1.3Variants
1.4Compatibility
1.5Needfortestmethods
1.6Enabling/disabling
1.7Explanatorynotes
2Definitionsrelatingtoechosuppressors
2.1Echosuppressor
2.2Fullechosuppressor
2.3Half-echosuppressor
2.4Differentialechosuppressor
2.5Partialbreak-inechosuppressor
2.6Adaptivebreak-inechosuppressor
2.7Suppressionloss
2.8Receiveloss
2.9Terminalechosuppressor(seeFigure5/G.164)
2.10Suppressionoperatetime
2.11Suppressionhangovertime
2.12Partialbreak-in
2.13Partialbreak-inoperatetime
2.14Fullbreak-in
2.15Fullbreak-inoperatetime
2.16Break-inhangovertime
2.17Differentialsensitivity
3Characteristicsofechosuppressorswithfixed
break-indifferentialsensitivity
3.1Transmissionperformance
3.2Characteristicswithsteady-stateinputsignals
appliedindependentlytothesendandreceive
paths
3.3Dynamiccharacteristicswhensignalsareapplied,
removedorchangedinthesendandreceivepaths
independently
3.4Performanceunderconditionsofsmallecho-path
lossandwhenend-delaymaybepresent
4Characteristicsofecho-suppressorwithadaptive
break-indifferentialsensitivity
4.1Provisionsof3
4.2Characteristicsoftheadaptivefunctionwith
signalsappliedindependentlytothesendand
receivepaths
5Characteristicsofecho-suppressortonedisablers
5.1General
5.2Disablingcharacteristics(seeFigure11/G.164)
5.3Guardbandcharacteristics
5.4Holding-bandcharacteristics
5.5Operatetime
5.6Falseoperationduetospeechcurrents
5.7Releasetime
6Testarrangementstomeasureessentialoperating
characteristicsofechosuppressors
6.1Generalconsiderations
6.2Measurementofstaticcharacteristics
6.3MeasurementofdynamiccharacteristicswhenLS
andLRareappliedindependently
6.4Measurementofecho-suppressoroperationwhen
theSisconnectedtoRportthroughanecho
paththatmayincludedelayaswell
6.5Measurementsofthespecificdynamic
characteristicsofadaptivebreak-inecho
suppressors
References