ETSI ETS 300 175-8 ed.2 (1996-09)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 8: Speech coding and transmission33.070.30'(&7Digital Enhanced Cordless Telecommunications (DECT)ICS:Ta slovenski standard je istoveten z:ETS 300 175-8 E23SIST ETS 300 175-8:199en01-GHFHPEHU1993SIST ETS 300 175-8:199SLOVENSKI
STANDARD
EUROPEANETS 300 175-8TELECOMMUNICATIONSeptember 1996STANDARDSecond EditionSource: ETSI TC-RESReference: RE/RES-03027-8ICS:33.060, 33.060.50Key words:DECT, radioRadio Equipment and Systems (RES);Digital Enhanced Cordless Telecommunications (DECT);Common Interface (CI);Part 8: Speech coding and transmissionETSIEuropean Telecommunications Standards InstituteETSI SecretariatPostal address: F-06921 Sophia Antipolis CEDEX - FRANCEOffice address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCEX.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.frTel.: +33 92 94 42 00 - Fax: +33 93 65 47 16Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and theforegoing restriction extend to reproduction in all media.© European Telecommunications Standards Institute 1996. All rights reserved.SIST ETS 300 175-8:1999

Page 2ETS 300 175-8: September 1996Whilst every care has been taken in the preparation and publication of this document, errors in content,typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to"ETSI Editing and Committee Support Dept." at the address shown on the title page.SIST ETS 300 175-8:1999

Page 3ETS 300 175-8: September 1996ContentsForeword.71Scope.92Normative references.93Definitions and abbreviations.113.1Definitions.113.2Abbreviations.124Configurations.134.1Reference configuration.134.1.1Basic configuration.134.1.2Portable Part (PP).144.1.2.1Functional organization.144.1.2.2Volume control.154.1.3Fixed Part (FP).154.1.3.1Digital interface.154.1.3.2Analogue interface.164.1.3.3FP adaptive volume control.164.2Test configurations.165Encoding.175.132 kbit/s full term (ADPCM).175.1.1Algorithm.175.1.2Bit sequence.175.2Other codings.176Transmission aspects.176.1Relative level.176.2Acoustic reference level.176.3Volume control.177Speech performance characteristics.187.1PP frequency responses.187.1.1Sending.187.1.2Receiving.187.2PP sending and receiving loudness ratings.187.2.1Nominal values.187.2.2User-controlled volume control in PP.197.2.3PP adaptive volume control.197.2.4FP adaptive volume control.207.3Sidetone.207.3.1Talker sidetone.207.3.2Listener sidetone.207.4Terminal coupling loss.217.4.1Weighted Terminal Coupling Loss (TLCw).217.4.1.1PP for the 3,1 kHz service (PSTN or ISDN).217.4.1.2FP with 4-wire interface.217.4.1.3FP with analogue 2-wire interface.227.4.1.4PP for unrestricted 64 kbit/s service.227.4.2Stability loss.227.4.2.1Requirement.227.4.2.2Test conditions.22SIST ETS 300 175-8:1999

Page 4ETS 300 175-8: September 19967.4.2.3Fixed geometry PP.227.4.2.4Variable geometry PP.227.5Distortion.237.5.1Sending.237.5.2Receiving.237.5.3Sidetone.237.5.4Recommended value for network planning.237.6Out of band signals.237.6.1Sending (discrimination against out of band input signals).237.6.2Receiving (spurious out of band signals).237.7Noise.247.7.1Sending.247.7.2Narrow-band noise.247.7.3Receiving.247.7.4Level of sampling frequency (receiving).247.8Acoustic shock.247.8.1Continuous signal.247.8.2Peak signal.247.9Delay.247.9.1DECT network.247.9.2PP.247.9.3FP.247.10Network echo control.257.11PP ambient noise rejection.258Additional features.268.1Loudspeaking and hand-free facilities.268.2Tandem with mobile radio network.268.2.1Tandem with GSM.268.2.1.1Network echo control.268.2.1.2Terminal coupling loss.268.2.1.3The GSM mobile transmitter operates in continuous mode.268.2.1.4The GSM mobile transmitter operates in discontinuousmode, DTX.268.3DECT connected to the GSM fixed network.278.3.1Network echo control.278.3.2Terminal coupling loss.278.4Wireless Relay Stations (WRS).278.4.1Modified FP network echo control requirements for implementation of 2and 3 CRFP links in cascade.28Annex A (informative):Description of "reference" echo control devices.29A.1Handset echo.29A.1.1Overview.29A.1.1.1Connection to the PSTN/ISDN.29A.1.1.1.1Local and national calls.29A.1.1.1.2Long distance connections with echo control devices in thePSTN/ISDN, e.g. calls via satellites.29A.1.1.2Connection to the GSM network.30A.1.2Implementation of the FP echo control function subclause 7.4.1.2 b.30A.1.2.1Suppression threshold.30A.1.2.2Static characteristics of activation control.31A.1.2.3Dynamic characteristics of activation control.31A.2Network echo.31A.2.1Soft suppressor implementation of requirement 2 of subclause 7.10.32A.2.1.1Static characteristics.32A.2.1.2Dynamic characteristics.32A.2.2Additional echo control for a 2-wire interface of requirement 1 of subclause 7.10.32SIST ETS 300 175-8:1999

Page 5ETS 300 175-8: September 1996A.2.3Echo canceller used for both requirements 1 and 2.33Annex B (informative):Local loop application.34B.1DECT tethered local loop replacement with 2-wire PP end system.34B.1.1TCLw requirements.34B.1.2Network echo.35B.2Quantization distortion considerations.35Annex C (informative):GSM Discontinuous Transmission (DTX), and Voice Activity Detection (VAD).36Annex D (informative):Speech levels in relation to ambient room noise and examples of adaptivevolume control settings.37Annex E (informative):Bibliography.38History.39SIST ETS 300 175-8:1999

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Page 7ETS 300 175-8: September 1996ForewordThis second edition European Telecommunication Standard (ETS) has been produced by the RadioEquipment and Systems (RES) Technical Committee of the European Telecommunications StandardsInstitute (ETSI).This ETS forms part 8 of a series of 9 laying down the arrangements for the Digital Enhanced CordlessTelecommunications (DECT) Common Interface (CI).Part 1:"Overview".Part 2"Physical layer (PHL)".Part 3"Medium Access Control (MAC) layer".Part 4"Data Link Control (DLC) layer".Part 5:"Network (NWK) layer".Part 6:"Identities and addressing".Part 7:"Security features".Part 8:"Speech coding and transmission".Part 9:"Public Access Profile (PAP)".Further details of the DECT system may be found in ETR 015, ETR 043, and ETR 056 (see annex E).Transposition datesDate of adoption of this ETS:6 September 1996Date of latest announcement of this ETS (doa):31 December 1996Date of latest publication of new National Standardor endorsement of this ETS (dop/e):30 June 1997Date of withdrawal of any conflicting National Standard (dow):30 June 1997SIST ETS 300 175-8:1999

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Page 9ETS 300 175-8: September 19961ScopeThis second edition European Telecommunication Standard (ETS) is part of the Digital Enhanced CordlessTelecommunications (DECT) Common Interface (CI) and specifies the speech coding and transmissionrequirements.In order to ensure satisfactory interworking of different portable and fixed units, it is necessary to specifythe transmission performance of the analogue information over the digital link. This requires not only use ofa common speech algorithm, but also standardization of frequency responses, reference speech levels (orloudness) at the air interface and various other parameters.This ETS applies to DECT equipment which includes all the necessary functions to provide real-timetwo-way speech conversation. A 3,1 kHz telephony teleservice conveyed over a DECT link (including FixedPart (FP) and Portable Part (PP)) which is capable of being connected (directly or indirectly) to the publicnetwork access point has to comply with the requirements in this ETS.Tethered fixed point local loop applications are not required to comply with the requirements of this part.The speech performance characteristics defined in this ETS typically conform to ETS 300 085 [19], whichspecifies the overall performance between the handset acoustic interface and a 64 kbit/s A-law PulseCode Modulated (PCM) digital network interface. The deviations from ETS 300 085 [19] are mainly due tothe consequences of non-PCM coding and transmission delay.The additional features described in clause 8 are those which are not included in ETS 300 085 [19], butwhich are likely to occur in a DECT system: analogue interface, loudspeaking and hand-free facilities,tandeming with a mobile radio network. Headsets are not covered by the present specifications.For the DECT systems which connect to the Public Switched Telephone Network (PSTN) via an analogueinterface, this ETS includes the basics on which the national specifications can be built, referring toETS 300 001 [20] (which specifies the connection of terminal equipments to the PSTN via a 2-wireanalogue interface) and the appropriate national standard.ETSI/STC TM5 has prepared a technical report, ETR 041, to be used as a guide for network planning.A summary of the control and the use of the DECT echo control functions, to guide on need for options tomanufacturers and installers, is found in the supplementary services clause of ETR 056.Information concerning test methods can be found in I-ETS 300 176 [9]. The test methods take intoaccount that DECT is a digital system.2Normative referencesThis ETS incorporates, by dated or undated reference, provisions from other publications. These normativereferences are cited at the appropriate places in the text and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this ETSonly when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies.[1]ETS 300 175-1 (1996): "Radio Equipment and Systems (RES); Digital EuropeanCordless Telecommunications (DECT); Common Interface (CI); Part 1:Overview".[2]ETS 300 175-2 (1996): "Radio Equipment and Systems (RES); Digital EuropeanCordless Telecommunications (DECT); Common Interface (CI); Part 2: PhysicalLayer (PHL)".[3]ETS 300 175-3 (1996): "Radio Equipment and Systems (RES); Digital EuropeanCordless Telecommunications (DECT); Common Interface (CI); Part 3: MediumAccess Control (MAC) layer".SIST ETS 300 175-8:1999

Page 10ETS 300 175-8: September 1996[4]ETS 300 175-4 (1996): "Radio Equipment and Systems (RES); Digital EuropeanCordless Telecommunications (DECT); Common Interface (CI); Part 4: DataLink Control (DLC) layer".[5]ETS 300 175-5 (1996): "Radio Equipment and Systems (RES); Digital EuropeanCordless Telecommunications (DECT); Common Interface (CI); Part 5: Network(NWK) layer".[6]ETS 300 175-6 (1996): "Radio Equipment and Systems (RES); Digital EuropeanCordless Telecommunications (DECT); Common Interface (CI); Part 6: Identitiesand addressing".[7]ETS 300 175-7 (1996): "Radio Equipment and Systems (RES); Digital EuropeanCordless Telecommunications (DECT); Common Interface (CI); Part 7: Securityfeatures".[8]ETS 300 444: "Radio Equipment and Systems (RES); Digital European CordlessTelecommunications (DECT): Generic Access Profile (GAP)".[9]I-ETS 300 176: "Radio Systems and Equipment (RES); Digital EuropeanCordless Telecommunications (DECT) Approval test specification".[10]CCITT Recommendation G.101 (1988): "The transmission plan".[11]CCITT
Recommendation G.131 (1988): "Stability and echo".[12]CCITT Recommendation G.164 (1988): "Echo suppressors".[13]CCITT Recommendation G.165 (1988): "Echo cancellers".[14]CCITT Recommendation G.701 (1988): "Vocabulary of digital transmission andmultiplexing, and pulse code modulation (PCM) terms".[15]CCITT Recommendation G.726 (1991): "40, 32, 24, 16 kbit/s adaptivedifferential pulse code modulation (ADPCM)".[16]CCITT Recommendation I.241 (1988): "Teleservices supported by an ISDN".[17]CCITT Recommendation P.10 (1988): "Vocabulary of terms on telephonetransmission quality and telephone sets".[18]CCITT Recommendation P.34 (1988): "Transmission characteristics ofhands-free telephones".[19]ETS 300 085: "Integrated Services Digital Network (ISDN): 3,1 kHz telephonyteleservice; Attachment requirements for handset terminals" (text relevant forNET 33).[20]ETS 300 001: "Attachments to Public Switched Telephone Network (PSTN);General technical requirements for equipment connected to an analoguesubscriber interface in the PSTN" (Candidate NET 4).[21]CCITT Recommendation G.113 (1988): "Transmission impairments".[22]CCITT Recommendation G.111 (1988): "Loudness ratings (LRs) in aninternational connection".[23]ETS 300 540: "Digital cellular telecommunications system (Phase 2);Transmission planning aspects of the speech service in the GSM Public LandMobile Network (PLMN) system (GSM 03.50)".SIST ETS 300 175-8:1999

Page 11ETS 300 175-8: September 19963Definitions and abbreviations3.1DefinitionsFor the purposes of this ETS, the following definitions apply:Central Control Fixed Part (CCFP): See ETS 300 175-1 [1].Cordless Radio Fixed Part (CRFP): See ETS 300 175-1 [1].DECT Network (DNW): See ETS 300 175-1 [1].double duplex bearer : See ETS 300 175-1 [1].End System (ES): See ETS 300 175-1 [1].fixed geometry Portable Part (PP): A PP in which the electro-acoustic transducers and their associatedacoustic components are held in fixed relative positions and/or orientations during all on-line conditions andtest conditions of the PP.Fixed Part (DECT Fixed Part) (FP): See ETS 300 175-1 [1].Fixed radio Termination (FT): See ETS 300 175-1 [1].Generic Access Profile (GAP): A standard in addition to the DECT CI that ensures interoperabilitybetween FPs and PPs from different manufacturers.handset echo: The echo, perceptible by the far-end user, resulting from the coupling between thereceiving and sending directions of the handset, mostly due to acoustic coupling between transducers. It isparticularly objectionable in communications including a satellite and an echo canceller, as the DECThandset echo may be out of range of the echo canceller.network (telecommunication network): See ETS 300 175-1 [1].network echo: The echo, perceptible by the DECT user, resulting from reflections in the network. It ismostly due to hybrid impairments at both ends of the communication.operator (DECT operator): See ETS 300 175-1 [1].Portable Handset (PHS): See ETS 300 175-1 [1].Portable Part (DECT Portable Part) (PP): See ETS 300 175-1 [1].Portable radio Termination (PT): See ETS 300 175-1 [1].public: See ETS 300 175-1 [1].public access service: See ETS 300 175-1 [1].Radio Fixed Part (RFP): See ETS 300 175-1 [1].Repeater Part (REP) : See ETS 300 175-1 [1].service provider (telecommunications service provider): See ETS 300 175-1 [1].telephony service: See CCITT Recommendation I.241 [16].user (of a telecommunication network): See ETS 300 175-1 [1].SIST ETS 300 175-8:1999

Page 12ETS 300 175-8: September 1996variable geometry PP: A PP that allows the position and/or orientation of its electro-acoustic transducersand their associated acoustic components to be changed during all on-line conditions of the PP.Wireless Relay Station (WRS): See ETS 300 175-1 [1].3.2AbbreviationsFor the purposes of this ETS, relevant definitions and abbreviations in CCITT Recommendations P.10 [17]and G.701 [14] apply. In addition the following abbreviations apply:ADPCMAdaptive Differential Pulse Code ModulationARLAcoustic Reference LevelCCFPCentral Control Fixed PartCICommon InterfaceCFRPCordless Radio Fixed PartCLRRCircuit Loudness Rating, ReceivingCLRSCircuit Loudness Rating, SendingCODECCoder-DecoderCRFPCordless Radio Fixed PartCSPDNCircuit Switched Public Data NetworkdBmdB relative to 1 milliwattdBm0The absolute power level in decibels referred to a point of zero relative leveldBrThe relative power level in decibelsDECTDigital Enhanced Cordless TelecommunicationsDNWDECT NetworkERPEar Reference PointESEnd SystemFPFixed PartFTFixed radio TerminationGAPGeneric Access ProfileISDNIntegrated Services Digital NetworkLELocal EchoLSTRListener Sidetone RatingMRPMouth Reference PointNLPNon-Linear ProcessorNWKNetworkOLROverall Loudness RatingP(A)BXPrivate (Automatic) Branch ExchangePAPPublic Access ProfilePHSPortable HandsetPPPortable PartPSPDNPacket Switched Public Data NetworkPSTNPublic Switched Telephone NetworkPTPortable radio TerminationPTNPrivate Telecommunication NetworkReFPReference Fixed PartRePPReference Portable PartREPREpeater PartRFPRadio Fixed PartRLRHReceiving Loudness Rating of the HandsetSLRHSending Loudness Rating of the HandsetTCLwweighted Terminal Coupling LossTELRTalker's Echo Loudness RatingSTMRSidetone Masking RatingQDUQuantization Distortion UnitWRSWireless Relay StationSIST ETS 300 175-8:1999

Page 13ETS 300 175-8: September 19964Configurations4.1Reference configuration4.1.1Basic configurationThe basic reference configuration for voice transmission over DECT is shown in figure 1.Acousticinterface+Volumecontrol+coderTranscoderUniformPCMto/fromair codeLineinterface+echocontrol+Volume control+coderTranscoderUniformPCMto/fromair codeUniformPCMreferencepointUniformPCMreferencepoint0]MRPERPAcousticinterfaceAirinterfaceLinePP (handset)FP (fixed part)Figure 1: Basic reference configurationThe PP and the FP are delimited by physical interfaces:-Acoustic:-from the PP towards the speaker-listener, with the Ear and Mouth Reference Points (ERPand MRP).-Air(RF):-the interface between PP and FP.-Line:-the interface from the FP towards the network.Uniform PCM reference points shall be introduced in both the PP and the FP to materialize the limits of thetransmission segment which is affected by the air interface coding scheme. This allows the transmissionrequirements to be specified independently from the coding at the air interface. The various transcodingalgorithms are level-transparent, i.e. with an encoder and decoder connected in tandem, the "levels" of thedigital signals at the uniform PCM input of the encoder and output from the decoder are identical. In aparticular implementation, the reference points may be embedded within an IC, and thus will not physicallyaccessible.SIST ETS 300 175-8:1999

Page 14ETS 300 175-8: September 1996Each of the three sections thus delimited deals with distinct functions:a)the PP electro-acoustic section (between acoustic interface and PP uniform PCM reference point)which includes the acoustic interface, the volume control and the analogue to digital conversion;b)the air-code section (between PP and FP uniform PCM reference points) considers the transcodingbetween uniform PCM and the air-code, as well as the transmission over the air interface;c)the FP line interface section (between FP uniform PCM reference point and line interface) comprisesthe interface to the line, digital or analogue, and the FP voice processing, e.g. echo control.Typically, the transmission features shall conform to ETS 300 085 [19] for the PP electro-acoustic section,and the line interface section in the case of digital interface. In the case of analogue interface, the lineinterface section realises the adaptation to ETS 300 001 [20] and to national standards.4.1.2Portable Part (PP)4.1.2.1Functional organizationFigure 2 represents the basic functional organization of a PP from the voice transmission point of view:Figure 2: PP functional organizationThe various functions represented in figure 2 are:a)the electro-acoustic function, which performs the interface to the transducers and the volumecontrol. The Handset Loudness Ratings (SLRH) and (RLRH) are defined between the acousticinterface and the uniform PCM reference point;b)the analogue to digital and digital to analogue coding to the uniform PCM reference point;c)the transcoder between uniform PCM and air-code.SIST ETS 300 175-8:1999

Page 15ETS 300 175-8: September 19964.1.2.2Volume controlThe volume control facility is optional, and can be implemented in a number of different ways:1)in the simplest implementation, it affects only the receiving level and is under the manual control ofthe PP user;2)the volume adjustment may also be adaptive, e.g. taking into account the average level of ambientnoise at the MRP;3)the volume control may affect both receiving and sending levels in opposite directions. This has theadvantage of reducing the effect on the terminal coupling loss. Such an implementation would fit anoisy environment, as the need for an increased receiving volume is likely to come from a loudambient noise, and it is then combined with a loud speech level.4.1.3Fixed Part (FP)4.1.3.1Digital interfaceFigure 3 shows the functional organization of a FP with a digital interface:Figure 3: FP functional organizationThe various functions represented in figure 3 are:a)a transcoder between air-code and uniform PCM;b)an echo control function which processes echoes coming back from both the handset and thenetwork. It provides additional losses that compensate for the increased length of the echo path dueto the DECT transmission delay over the air interface;c)a transcoder from uniform PCM to A-law PCM towards the line interface.SIST ETS 300 175-8:1999

Page 16ETS 300 175-8: September 19964.1.3.2Analogue interfaceThe organization of a FP with an analogue interface is shown in figure 4.Figure 4: FP with an analogue interfaceThe various functions represented in figure 4 are:a)the line interface comprises the digital to analogue coder-decoder and the adaptation to the line, thatcan be either 2- or 4-wire. The Circuit Loudness Ratings (CLRR and CLRS) are defined betweenuniform PCM reference point and the line interface;b)in the case of a 2-wire line, the network echo controller deals with the local hybrid echo, which issuperimposed on the network echo in a manner similar to the digital line interface.NOTE:Due to different transmission characteristics of the 2-wire local access in Europeancountries, it is recommended that careful attention is paid to the transmissionspecification of the 2-wire FP interface, particularly in respect of transmission loss andimpedance.4.1.3.3FP adaptive volume controlAn adaptive dual volume adjustment, as described in subclause 4.1.2.2, may optionally be implementedinto the FP, for base stations where the associated PPs may be used in a noisy environment (e.g. publicaccess).4.2Test configurationsA DECT system comprises a FP and a PP. As these parts are not always purchased together, it is arequirement that either the complete system or each of the two separate parts shall be capable of beingtested (see I-ETS 300 176 [9]).SIST ETS 300 175-8:1999

Page 17ETS 300 175-8: September 19965Encoding5.132 kbit/s full term (ADPCM)5.1.1AlgorithmThe speech coding algorithm shall conform to CCITT Recommendation G.726 [15] for 32 kbit/s AdaptiveDifferential Pulse Code Modulation (ADPCM).The A-law companding and synchronous tandem adjustment may be omitted in FPs with an analogue lineinterface and in PPs.NOTE:CCITT Recommendation G.726 [15] 32 kbit/s ADPCM codecs support the use of thevoice channel for telefax of group 2 and group 3. For group 3 the data speed, which isautomatically negotiated, is limited to 4,8 kbit/s.5.1.2Bit sequenceThe ADPCM words comprised in each burst shall be transmitted in chronological order, and with the mostsignificant bit transmitted first within each word.5.2Other codingsNo other coding scheme is permitted at this time. When introducing a new coding the following speechperformance characteristics shall be reviewed:-frequency response;-distortion;-delay; and-if the latter is widely affected, terminal coupling loss and network echo control.6Transmission aspects6.1Relative levelThe digital line interface is a 0 dBr point according to CCITT Recommendation G.101 [10]. As the variousdigital transcoding algorithms are essentially loss-less, the relative level is constant over the whole digitalpath in the PP and the FP.6.2Acoustic reference levelThe acoustic reference level is defined as the acoustic level which corresponds to a level of- 10 dBm0 atthe digital interface.6.3Volume controlUnless stated otherwise, if a user-controlled volume control is provided at the PP, the requirements applyfor all positions of the volume control, and the compliance tests shall be carried out at the maximum settingof this volume control.NOTE:The testing of a PP with a dual or an adaptive volume control requires further study.SIST ETS 300 175-8:1999

Page 18ETS 300 175-8: September 19967Speech performance characteristics7.1PP frequency responses7.1.1SendingThe sending sensitivity-frequency response (from MRP to the digital interface) shall be within a mask asdefined in table 1.Table 1: Sending sensitivity-frequency mask¸¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¾¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¾¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¹¼¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶À¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶À¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶½¼¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¿¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¿¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶½º¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶»7.1.2ReceivingThe receiving sensitivity-frequency response (from the digital interface to the ERP) shall be within a maskas defined in table 2.Table 2: Receiving sensitivity-frequency mask¸¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¾¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¾¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¹¼¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶À¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶À¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶½¼¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¿¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¿¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶½º¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶»7.2PP sending and receiving loudness ratings7.2.1Nominal valuesThe nominal values are:-Sending Loudness Rating (SLRH) = 7 dB; and-Receiving Loudness Rating (RLRH) = 3 dB.There is a manufacturing tolerance of ± 3,5 dB on both RLRH and SLRH.NOTE:CCITT/ITU-T test methods on loudness ratings are valid only for codecs that cantransmit sinusoids without excessive distortion.SIST ETS 300 175-8:1999

Page 19ETS 300 175-8: September 19967.2.2User-controlled volume control in PPTwo types of user-controlled volume control shall be permitted.A user-controlled volume control shall be provided in all PP equipment, except where an adaptive volumecontrol is incorporated in the PP.When adjusting the volume control from nominal to maximum setting, the decrease in RLRH shall be notless than 6dB.Where user controlled volume control is provided instead of an adaptive volume control, adjust the volumecontrol to the setting (nominal) where the RLR is closest to its nominal value. At this setting the RLRH andSLRH shall simultaneously meet the values given in subclause 7.2.1, including the tolerances. A "jointacting" volume control is where the PP can simultaneously change the values of SLR and RLR in oppositedirections.The RLRH and SLRH shall not exceed the limits given in tables 5 and 6.Table 3: Absolute limits for "joint-acting" volume controlVolume settingMaximumMinimumRLRH- 13 dB19 dBSLRH17 dB3 dBTable 4: Absolute limits for a receiving volume controlVolume settingMaximumMinimumRLRH- 13 dB19 dBNOTE 1:Minimum setting: The setting where the RLR has its maximum valueMaximum setting: The setting where the RLR has its minimum valueNOTE 2:A user-controlled volume control should include an automatic reset function that ensuresthat the default setting for each new call is no higher than the nominal setting.NOTE3: Analogue networks generally require higher receive levels (lower RLR) than digitalnetworks (ISDN). This is to compensate for old long lossy analogue lines that still existin many PSTNs. This gives an interworking problem between analogue networks andterminals that use digital codecs as in DECT systems and ISDN terminals. Most of thecalls do not have lossy lines, and then the receive signal becomes very high, whichcould cause distortion in the A/D converters and also lower the margin for the wantedterminal echo loss. The best solution is to adjust the general national requirements foranalogue terminals, so that 4 to 6 dB higher RLR is allowed when a DECT system isthe terminal of an analogue connection to the PSTN. This would not violate any nationalplanning rules, since each DECT PP has at least + 6 dB volume control to compensatefor any lossy connection. Some national administrations have already implemented thisprinciple.7.2.3PP adaptive volume controlThe PP shall inform the FP if an adaptive volume control is implemented in the PP. Subclause 7.7.41 inETS 300 175-5 [5] describes how this shall be done.This function is for further study and may follow GSM, or other, specifications when available.SIST ETS 300 175-8:1999

Page 20ETS 300 175-8: September 19967.2.4FP adaptive volume controlAn adaptive volume control, depending on the level of environmental noise at the PP, may be implementedinto the FP. The gain variation shall be symmetrical, i.e. the increase in the receiving direction shall beequal to the decrease in the sending direction.If the PP adaptive volume control feature is implemented then the FP adaptive volume control feature shallbe disabled.NOTE 1:The PP ambient noise level is calculated in the FP based upon the minimum ambientnoise rejection requirement as specified in subclause 7.11.NOTE 2:For an FP with an analogue interface, problems of saturation may occur depending onnational RLR values.See annex D for further information.7.3Sidetone7.3.1Talker sidetoneThe sidetone path shall be implemented in the PP.The nominal value of the Sidetone Masking Rating (STMR) shall be 13 dB. There is a manufacturingtolerance of - 3 dB to + 5 dB. The requirement shall be met with SLRH and RLRH corrected to the nominalvalues of SLRH and RLRH.NOTE:It is recommended that the sidetone level is independent of the receiving volumecontrol.7.3.2Listener sidetoneThe value of the LSTR shall not be less than 10 dB referred to the nominal values of SLRH and RLRH.For PPs with noise rejection capability as declared by the applicant, the value of the LSTR shall not be lessthan 15 dB referred to the nominal values of SLRH and RLRH.Alternatively the value of the weighted average D of the difference of the send sensitivities between diffuseand direct sound shall be measured and shall not be less then -5 dB and with noise rejection the weightedaverage D shall not be less then +0 dB. One of both alternatives shall be declared by the applicant.NOTE:The noise rejection capability option is recommended for PPs used in noisyenvironments.PPs with declared noise rejection capability option shall indicate this to the FP before or at call set-up byincluding this information in the <> information element. See ETS 300 175-5 [5]subclause 7.7.41.SIST ETS 300 175-8:1999

Page 21ETS 300 175-8: September 19967.4Terminal coupling lossThe PP shall be suspended in free air.7.4.1Weighted Terminal Coupling Loss (TLCw)7.4.1.1PP for the 3,1 kHz service (PSTN or ISDN)For a PP that is designed to provide the 3,1 kHz service, either on ISDN or PSTN, the weighted TerminalCoupling Loss (TCLw) defined from the PP digital input to the PP digital output shall meet one of thefollowing options:a)TCLw > 46 dB at nominal setting of the volume control corrected to the nominal values of RLRH andSLRH. For all positions of volume control the TCLw shall not be less than 35 dB.NOTEThis is the recommended option.b)TCLw > 34 dB.If the PP is of type a) then it shall send this information "Full TCL" to the FP as defined inETS 300 175-5 [5], subclause 7.7.41 before or at call set-up.If the FP receives no information concerning the TCLw value of the PP, the FP shall default to theassumption that the PP is of type b).7.4.1.2FP with 4-wire interfaceThe FP echo control functions described below shall be connected or disabled depending on a messagefrom the PP or depending on call routing information and on type of service. It is recommended to disablethem when it is known that the one-way delay of the connection is less than 25 ms excluding the DECTdelay (e.g. internal Private Automatic Branch eXchange (PABX) connections). They may be disabled if thePP has TCLw > 46 dB.A FP with a 4-wire interface (analogue or digital) shall meet at least one of the two following requirements:a)artificial echo loss:-an artificial echo path shall be implemented into the FP between the line input and the line output, asshown in figure 5. The loss of that echo path shall be 24 dB ± 2 dB.NOTE 1:The artificial echo simulates the echo from a very good analog 2-wire telephone. When a publicnetwork operator uses an echo canceller in the network (e.g. for a satellite link), the artificialecho loss path provides an in-range echo to ensure that the echo canceller and its Non-LinearProcessor (NLP) is active. The NLP cancels the 34 dB DECT handset echo. See annex A,subclause A.1.1.In some countries the echo cancellers in the public network do not depend on the artificial echopath to activate the NLP. Installations in such countries could have the artificial echo pathpermanently disabled.Figure 5: Artificial echo path in a 4-wire FPSIST ETS 300 175-8:1999

Page 22ETS 300 175-8: September 1996b)echo control device:-an echo control device shall be implemented into the FP. The weighted Terminal Coupling Loss(TCLw) of the DECT system, defined from the FP line input to the FP line output, shall be at least46 dB.NOTE 2:Option a) is the option normally used for connections to the PSTN/ISDN. Option b) isneeded, e.g. for tandem connection with GSM, subclauses 8.2.1 and 8.3.2. Annex A,subclause A.1.2 provides, for guidance and illustration, the description of a NLPimplementation of option b). The control range for an echo canceller and hangover timefor an NLP should be greater than or equal to 40 ms. A soft suppressor implementationis not recommended.NOTE 3:The connect/disable function for options a) and b) is required for approval testing underI-ETS 300 176 [9]. Messages from the PP with control information are defined inETS 300 175-5 [5] subclause 7.7.16.7.4.1.3FP with analogue 2-wire interfaceThere is no specific requirement on a FP with an analogue 2-wire interface to the PSTN/ISDN.7.4.1.4PP for unrestricted 64 kbit/s serviceThe unrestricted 64 kbit/s service is outside the scope of this ETS.7.4.2Stability loss7.4.2.1RequirementIn the test conditions described below the attenuation from the digital input to the digital output shall be atleast 6 dB at all frequencies in the range of 200 Hz to 4 000 Hz.7.4.2.2Test conditions7.4.2.3Fixed geometry PPThe handset shall be lying on, and the transducers facing, a hard surface.7.4.2.4Variable geometry PPThe equipment shall be capable of meeting the requirement in at least one of the two following conditions:a)if it is possible to position the earpiece in front of the mouthpiece with a distance of 150 mmbetween the front planes of each, the requirement shall be met in this relative position and in the justoff-hook position;b)if the relative movement and orientation of the acoustic and electro-magnetic elements are limited bymeans of a hinge or similar mechanism, the requirement shall be met in any relative position andorientation that can be achieved whilst the PP is in active condition, i.e. a communication isestablished over the air interface.SIST ETS 300 175-8:1999

Page 23ETS 300 175-8: September 19967.5Distortion7.5.1SendingThe ratio of signal to total distortion (harmonic and quantizing) measured at the line interface shall not beless than 35 dB.7.5.2ReceivingThe ratio of signal to total distortion (harmonic and quantizing) measured at the ERP shall not be less than33 dB.7.5.3SidetoneThe third harmonic distortion generated by the PP shall not be greater than 10 %.7.5.4Recommended value for network planningAccording to CCITT Recommendation G.113 [21], the PCM-to-ADPCM-to-PCM transcoding introduces2,5 QDU (quantizing distortion units). Therefore, the following values shall be taken into account fornetwork planning purpose:-3 QDU if the FP interfaces to a digital line, or 3,5 QDU if the FP interfaces to an analogue line. Forfurther information see ETR 041.7.6Out of band signals7.6.1Sending (discrimination against out of band input signals)With any sine-wave signal above 4,6 kHz and up to 8 kHz applied at the MRP at a level of- 4,7 dBPa, thelevel of any image frequency produced at the digital interface shall be below a reference level obtained at1 kHz (- 4,7 dBPa at MRP) by at least the amount in dB specified intable 5.Table 5: Discr
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