1、 ETSI ES 202 020 V1.4.2 (2007-06)ETSI Standard Speech Processing, Transmission and Quality Aspects (STQ);Harmonized Pan-European/North-American approach to lossand level planning for voice gateways to IP based networksfloppy3 ETSI ETSI ES 202 020 V1.4.2 (2007-06) 2 Reference RES/STQ-00106 Keywords Q
2、oS, quality, speech, transmission, voice ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice Indivi
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4、 Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the curr
5、ent status of this and other ETSI documents is available at http:/portal.etsi.org/tb/status/status.asp If you find errors in the present document, please send your comment to one of the following services: http:/portal.etsi.org/chaircor/ETSI_support.asp Copyright Notification No part may be reproduc
6、ed except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2007. All rights reserved. DECTTM, PLUGTESTSTM and UMTSTM are Trade Marks of ETSI registered for the benefit of its Members.
7、 TIPHONTMand the TIPHON logo are Trade Marks currently being registered by ETSI for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. ETSI ETSI ES 202 020 V1.4.2 (2007-06) 3 Contents Intellectual Property Rig
8、hts4 Foreword.4 1 Scope 5 2 References 6 3 Definitions and abbreviations.6 3.1 Definitions6 3.2 Abbreviations .7 4 Loss and level planning8 4.1 Overview 8 4.2 Half-channel loss and level plans .8 4.3 Loudness rating definitions 8 4.3.1 Loudness rating.8 4.3.2 Relationship between loudness ratings an
9、d loss plans9 4.4 0 dBr Reference level point11 4.5 Reference level.11 4.5.1 Network level changes11 4.6 Harmonized half-channel loss and level plans .11 4.7 Regional full-channel loss and level plans .12 5 Requirements for the harmonized half-channel loss and level plan.12 5.1 The Pan-European half
10、-channel loss plan 13 5.1.1 Voice Gateway connections13 5.1.2 Interface descriptions14 5.1.3 Voice Gateway half-channel loss plan15 5.2 The North American half-channel loss plan.16 5.2.1 Voice Gateway connections16 5.2.2 Port descriptions .16 5.2.3 Voice Gateway half-channel loss plan18 Annex A (inf
11、ormative): Loss and level planning and loudness ratings .19 A.1 Introduction 19 A.2 Send and receive levels 19 A.3 Telephone equipment loudness ratings 20 A.4 Interface-to-interface loss allocation22 Annex B (informative): The Pan-European loss and level plan.24 B.1 Overview 24 B.2 The Pan-European
12、LR and loss plan derivations .24 B.3 The Pan-European full-channel loss plan.25 B.4 Calculation spreadsheet26 Annex C (informative): The North American loss and level plan27 C.1 Overview 27 C.2 The North American full-channel loss plan .27 Annex D (informative): Relationship of channel based loss pl
13、ans to Q.55129 Annex E (informative): Bibliography.30 History 31 ETSI ETSI ES 202 020 V1.4.2 (2007-06) 4 Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicl
14、y available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI We
15、b server (http:/webapp.etsi.org/IPR/home.asp). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or
16、may be, or may become, essential to the present document. Foreword This ETSI Standard (ES) has been produced by ETSI Technical Committee Speech Processing, Transmission and Quality Aspects (STQ). The North American version of this joint work is the “Voice Gateway Transmission Requirements“ standard.
17、 Within TIA it has the number ANSI/TIA-912-B 1. ETSI ETSI ES 202 020 V1.4.2 (2007-06) 5 1 Scope The purpose of the present document is the harmonization of loss and level planning between the Pan-European and the North American regions, with a global view and the intent that the present document may
18、 be subject to adoption by other regions, in future. An equivalent standard has been published by the North American Telecommunications Industries Association (ANSI/TIA-912-B 1). The objective of the present document is to specify a loss plan for IP based networks particularly suitable for use by vo
19、ice gateway manufacturers operating in Europe. The recommended loss values are based on: - Pan-European analogue telephone sets as specified in TBR 038 3; - digital sets as specified in ITU-T Recommendation P.310 7; and - typical European public network losses. These loss values may not provide opti
20、mum performance in conjunction with network operators whose telephone set loudness ratings or network losses differ significantly from the values used in the present document. Manufacturers may need to modify their loss plans accordingly, but the principles described in the present document provide
21、guidance on how to derive suitable loss values. A spreadsheet is also provided as an annex to assist manufacturers in determining the correct loss values. The PBX ports referred to in the present document are as defined in ES 201 168 2 or ANSI/TIA-912-B 1. NOTE: The present document introduces two v
22、ariants of the L2 interfaces for transmission planning purposes. The present document applies to all kind of voice services, irrespective whether they provide: - real time conversational telecommunication between human subjects; or - listening-only telecommunication from a machine interface (stored
23、speech) to a human subject; or - speaking-only telecommunication from a human subject to a machine interface. The present document is initially limited to voice gateways interfacing to IP telephony networks. For the purposes of the present document, a voice gateway is considered to be a device that
24、performs routing functions between: - telephones (analogue, digital, IP); - public and private network trunks; - IP based networks. The present document may apply also to loss planning in any purely digital transmission network which may include: - circuit switched networks; - frame relay or ATM net
25、works; - mobile networks. While the present document does not apply to other services, which may be carried over the same infrastructure, e.g. Voiceband Data or Fax; nevertheless, complying with the present document will, in general, be advantageous for such other services. ETSI ETSI ES 202 020 V1.4
26、.2 (2007-06) 6 2 References The following documents contain provisions which, through reference in this text, constitute provisions of the present document. References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For a specific refe
27、rence, subsequent revisions do not apply. For a non-specific reference, the latest version applies. Referenced documents which are not found to be publicly available in the expected location might be found at http:/docbox.etsi.org/Reference. NOTE: While any hyperlinks included in this clause were va
28、lid at the time of publication ETSI cannot guarantee their long term validity. 1 ANSI/TIA-912-B (2007): “Telecommunications - IP Telephony Equipment - Voice Gateway Transmission Requirements“. 2 ETSI ES 201 168 (V1.2.1): “Speech processing, Transmission and Quality aspects (STQ); Transmission charac
29、teristics of digital Private Branch eXchanges (PBXs) for interconnection to private networks, to the public switched network or to IP gateways“. 3 ETSI TBR 038 (1998): “Public Switched Telephone Network (PSTN); Attachment requirements for a terminal equipment incorporating an analogue handset functi
30、on capable of supporting the justified case service when connected to the analogue interface of the PSTN in Europe“. 4 ITU-T Recommendation G.100: “Definitions used in Recommendations on general characteristics of international telephone connections and circuits “. 5 ITU-T Recommendation G.101: “The
31、 transmission plan“. 6 ITU-T Recommendation G.107: “The E-Model, a computational model for use in transmission planning“. 7 ITU-T Recommendation P.310: “Transmission characteristics for telephone band (300-3 400 Hz) digital telephones“. 8 ITU-T Recommendation G.111: “Loudness ratings (LRs) in an int
32、ernational connection“. 9 ITU-T Recommendation G.121: “Loudness ratings (LRs) of national systems“. 3 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: decoding: digital-to-analogue conversion encoding: analogue-to-digi
33、tal conversion full-channel loss plan: loss plan where each loss is defined for a complete path between two acoustical interfaces half-channel loss plan: loss plan where each loss is defined for a path between an acoustical interface and an (electrical) standard reference point, the 0 dBr point half
34、-channel receive loudness rating: RLRHCis defined as the RLR at the 0 dBr point half-channel send loudness rating: SLRHCis defined as the SLR at the 0 dBr point ETSI ETSI ES 202 020 V1.4.2 (2007-06) 7 interface: Pan-European term for the input or output circuit connections loudness rating: send and
35、receive loudness ratings are collectively referred to as the loudness rating port: North American term for the input or output circuit connections receive loudness rating: electrical/acoustic conversion characteristic of the terminating equipment reference level: half-channel send loudness rating of
36、 8 dB reference level point: VG-to-IP network connection point (also termed the 0 dBr or zero-level point) send loudness rating: acoustic/electrical conversion characteristic of the originating equipment telephony terminal: terms telephone, terminal equipment, and end point are equivalent, and refer
37、 to the device that performs the acoustic/electrical conversion NOTE: The terms interface and port are used interchangeably in the present document. transcoding: transcoding refers to the conversion from one voice coding algorithm to another NOTE: E.g. ITU-T Recommendations G.711 to G.729A (see bibl
38、iography). voice gateway: device which routes packetized voice from one end-point to another, and provides other voice related functions that a data gateway would not provide NOTE: It may provide interfaces to analogue and digital voice terminals and access to public and private switched telephone n
39、etworks and WANs. 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: AAL Analogue Access Line (Analogue Interface at DEO) AAL(D) Analogue Access Line (Digital Interface at PBX) ATM Asynchronous Transfer Modus ATT Analogue Tie Trunk CATV CAble TV CB Channel
40、 Bank DAL Digital Access Line dBSPL Sound Pressure Level in dB DC Direct Current DEO Digital End Office DGS DiGital Station DT Digital TrunkDTMF Dual Tone Multi Frequency FXD Foreign eXchange Digital FXO Foreign eXchange Office FXS Foreign eXchange Station IAD Integrated Access Device IP Internet Pr
41、otocolLAN Local Area Network LD Loss Distortion LR Loudness Rating MRP Mouth Reference Point (according to ITU-T Recommendation P.64) MTA Multimedia Terminal Adaptor OLR Overall Loudness Rating ONS On Premise Station OPS Off Premise Station PAL Packet Access LinePBX Private Branch eXchange PBX Priva
42、te Branch eXchanges PSTN Public Switched Telephone Network RLR Receive Loudness Rating ETSI ETSI ES 202 020 V1.4.2 (2007-06) 8 RLRHCHalf-Channel Receive Loudness Rating RLRTTelephone Receive Loudness Rating SLR Send Loudness Rating SLRHCHalf-Channel Send Loudness Rating SLRTTelephone Send Loudness R
43、ating TDM Time Division Multiplex TELR Talker Echo Loudness Rating VG Voice Gateway WAN Wide Area Network 4 Loss and level planning 4.1 Overview Developing a loss plan can be a complex process, as the objective is to ensure a satisfactory overall loudness rating for all connections types. To do this
44、 the loudness ratings of the end points (telephones) and the transmission loss between the end points, for each connection type must be known. This is a trivial exercise in a purely IP telephony environment, if one assumes that the end points are digital telephone sets with an LR of 8 dB and 2 dB (i
45、n line with the ITU-T Recommendation G.101 5), and that no gains or losses are introduced in the digital transmission path. In this case the OLR for any digital telephone set-to-set connection world-wide is 10 dB, which is the ITU-T objective. The complexity is introduced when the IP telephony netwo
46、rk connects to analogue telephones and trunks. In this case the LRs of the telephones and trunks vary, although a loss-less digital transmission path can be maintained. A half-channel loss plan for national and international IP telephony networks can be implemented based on the premise that only the
47、 LRs vary, and that the IP network does not introduce any additional gain or loss. VGs can also connect to existing analogue and TDM based digital networks. In North America these connections require losses to be defined on a port-to-port basis for technical and sometimes regulatory reasons, and ful
48、l-channel loss plans are required for VGs. 4.2 Half-channel loss and level plans The basic concept in the half-channel loss plan is to adjust all send levels on an IP telephony network to the optimum SLRHC of 8 dB. Digital telephone sets provide the reference SLR of 8 dB by definition. This is not a
49、n original concept, as it is the basis of the European dBr reference system. The recent move to standardize the North American digital telephone set LRs to the ITU-T recommended levels now makes this practical for IP telephony networks. NOTE: Clause 5 of the present document describes the half-channel loss implementation in more detail. The same basic concept could be applied to the current non-IP PSTN and private networks, but existing industry standards and regulatory requirements may make it difficult to implement. 4.3 Loudness rating de
