ITU G.121:1993
ITU G.121:1993 Loudness Ratings (lrs) Of National Systems
Table of Contents
1NominalLRsofthenationalsystems1.1DefinitionofnominalLRsofthenational
systems
1.2Traffic-weightedmeanvaluesofthedistribution
ofsendandreceiveloudnessratings,SLRsand
RLRs
2MaximumSendandReceiveLoudnessRatings,SLRand
RLR
2.1Valuesforeachdirectionoftransmission
2.2Differenceintransmissionlossbetweenthetwo
directionsoftransmissioninnationalsystems
3MinimumSLR
4DeterminationofnominalLoudnessRatings
5Side-tone
5.1General
5.2Talker'sside-toneSTMR
5.3Listener'sside-toneLSTR
6IncorporationofPCMdigitalprocessesinnational
extensions
6.1Effectonnationaltransmissionplans
6.2Transmissionlossconsiderations
AnnexAEvaluationofthenominaldifferencesofloss
betweenthetwodirectionsoftransmission
AnnexBTransmissionconsiderationsfora4-wireloop
insertedina2-wirecircuit
B.1General
B.2Attenuation
B.3Impedance
B.4Side-toneconsiderations
AnnexCExamplesofvaluesofRandTpadsadoptedby
someadministrations