1、ETSI TR 1 O1 329-1 V3.1.2 (2002-01) Technical Repor Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON) Release 3; End-to-end Quality of Service in TIPHON systems; Part 1: General aspects of Quality of Service (QoS) 2 ETSI TR 101 329-1 V3.1.2 (2002-01) Reference RTR/TIPHON-
2、05007 2 Keywords internet, telephony, quality ETSI 650 Route des Lucioles F-O6921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 Siret No 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-prfecture de Grasse (06) No 7803/88 Important notice
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6、 all media. O European Telecommunications Standards Institute 2002. All rights reserved. ETSI 3 ETSI TR 101 329-1 V3.1.2 (2002-01) Contents Intellectual Property Rights 4 Foreword . 4 Introduction 5 1 2 3 3.1 3.2 4 4.1 4.1.1 4.1.2 4.1.3 4.2 4.3 4.3.1 4.3.2 4.3.3 4.3.4 4.4 4.4.1 4.4.2 4.4.3 4.4.4 4.4
7、.5 4.4.6 5 5.1 5.2 5.3 5.4 5.5 Scope 6 References 6 Definitions and abbreviations . 6 Definitions 6 Abbreviations 7 Introduction to end-to-end Quality of Service (QoS) . 8 Main QoS parameters influenced by TIPHON systems . 8 Call set-up quality . 8 Call quality 8 Conversational speech quality 8 Furt
8、her QoS parameters 9 TIPHON specific QoS relevant factors 9 Delay Jitter 9 Jitter buffers 10 Jitter Buffer Implementations . 11 Jitter buffer monitoring capabilities . 12 Physical components based on which a TIPHON service may be provided 12 IP terminal 12 IP access network . 13 IP backbone 13 IWF (
9、gateway/gatekeeper) 13 SCN 13 Voice terminal connected to the SCN . 14 Depiction of each TIPHON scenario by its reference connection 15 Reference connection for TIPHON scenario #O . 15 Reference connection for TIPHON scenario #1 . 16 Reference connection for TIPHON scenario #2 . 16 Reference connect
10、ion for TIPHON scenario #3 . 17 Reference connection for TIPHON scenario #4 . 17 Annex A: Bibliography 18 History 19 ETSI 4 ETSI TR 101 329-1 V3.1.2 (2002-01) Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
11、pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR O00 314: “Intellectual Property Rights (7PRs); Essential, orpotentially Essential, IPRs notlJied to ETSI in respect ofETSI standards“, which is available from the ETSI Secr
12、etariat. Latest updates are available on the ETSI Web server (5). 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 O00 3 14 (or the updates on the ETSI Web se
13、rver) which are, or may be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by ETSI Project Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON). The present document is part 1 of a multi-part deliverable covering End-t
14、o-end Quality of Service in TIPHON systems, as identified below: TR 101 329-1: “General aspects of Quality of Service (QoS)“; TS 101 329-2: “Definition of speech Quality of Service (QoS) classes“; TS 101 329-3: TS 101 329-5: TR 101 329-6: “Signalling and control of end-to-end Quality of Service (QoS
15、)“; “Quality of Service (QoS) measurement methodologies“; “Actual measurements of network and terminal characteristics and performance parameters in TIPHON networks and their influence on voice quality“; “Design guide for elements of a TIPHON connection from an end-to-end speech transmission perform
16、ance point of view“. TR 101 329-7: Quality of Service aspects of TIPHON Release 4 and 5 Systems will be covered in TS 102 024 and TS 102 025 respectively (see Bibliography), and more comprehensive versions of the Release 3 documents listed above will be published as part of Release 4 and 5 as work p
17、rogresses. ETSI 5 ETSI TR 101 329-1 V3.1.2 (2002-01) I n t rod uct ion The present document forms one of a series of technical specifications and technical reports produced by TIPHON Working Group Saddressing Quality of Service (QoS) in TIPHON Systems. The structure of this work is illustrated in fi
18、gure 1. Introduction Definition of 5 Speech Classes TR 101 329-1 General Aspects of QoS TS 101 329-2 Speech QoS Classes f GenericQoS Specific Aspects of QoS TS 101 329-3 Control QoS signalling requirements TS 101 329-5 Measure- ment Methods Measurement methodologies TR 101 329-6 Actual Test Results
19、Repository of real test results TR 101 329-7 Design Guidelines Useful info for designers Figure 1: Structure of TIPHON QoS Documentation for Release 3 ETSI 6 ETSI TR 101 329-1 V3.1.2 (2002-01) 1 Scope The present document presents QoS related background information for IP networks that provide voice
20、 telephony in accordance with all TIPHON scenarios. It contains: - - a depiction of each TIPHON scenario by its reference connection; an overview of the physical components based on which a TIPHON service may be provided. 2 Re fe re nces For the purposes of this Technical Report (TR) the following r
21、eferences apply: il ETSI EG 202 306: “Transmission and Multiplexing (TM); Access networks for residential customers“. 21 ETSI TS 101 3 12: “Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON); Network architecture and reference configurations; Scenario 1 I. ETSI TS 101 329-
22、2: “Telecommunications and Internet Protocol Harmonization over Networks (TIPHON); End to End Quality of Service in TIPHON Systems; Part 2: Definition of Quality of Service (QoS) Classes“. ETSI TS 101 329-5: “Telecommunications and Internet protocol Harmonization Over Networks (TIPHON) Release 3; Te
23、chnology Compliance Specification; Part 5: Quality of Service (QoS) measurement methodologies“. ITU-T Recommendation E.600: “Terms and definitions of traffic engineering“. ITU-T Recommendation G. 103 : “Hypothetical reference connections“ ITU-T Recommendation G. 107: “The E-Model, a computational mo
24、del for use in transmission planning“. ITU-T Recommendation G. 177: “Transmission planning for voiceband services over hybrid Internet/PSTN connections“. 31 41 51 61 71 SI 91 ITU-T Recommendation 1.350: “General aspects of quality of service and network performance in digital networks, including ISD
25、Ns“. ITU-T Recommendation P.3 10: “Transmission characteristics for telephone-band (300-3 400 Hz) digital telephones“. lo1 3 3.1 Definitions and abbreviations De fi nit ions For the purposes of the present document, the following terms and defiiitions apply: end-to-end delay jitter: estimate of the
26、statistical variance of the voice frames interarrival time measured in milliseconds and expressed as an unsigned integer NOTE: The end-to-end delay jitter is defiied to be the mean deviation (smoothed absolute value) of the difference in voice frame spacing at the receiver compared to the sender for
27、 a pair of voice frames. ETSI 7 ETSI TR 101 329-1 V3.1.2 (2002-01) interarrival jitter: estimate of the statistical variance of the RTP data packet interarrival time measured in milliseconds and expressed as an unsigned integer NOTE: The interarrival jitter is defied to be the mean deviation (smooth
28、ed absolute value) of the difference in packet spacing at the receiver compared to the sender for a pair of packets. jitter amplitude: absolute difference in arrival time between the fastest and the slowest data packet or voice frame 3.2 Abbreviations For the purposes of the present document, the fo
29、llowing abbreviations apply: ADSL BRAN FDM GSM ISDN IP ITU ITU-T IWF LAN PSTN RTP SCN TDM UMTS VDSL XDSL QOS Asymmetric Digital Subscriber Line Broadband Radio Access Networks Frequency Division Multiplex Global System for Mobile communications Integrated Services Digital Network Internet Protocol I
30、nternational Telecommunication Union ITU Telecommunication Standardization Sector (former CCITT) Interworking Function Local Area Network Public Switched Telephone Network Quality of Service Real Time Protocol Switched Communications Network Time Division Multiplex Universal Mobile Telecommunication
31、s System Very High Speed Digital Subscriber Line ADSL, VDSL and other Digital Subscriber Line Techniques ETSI 8 ETSI TR 101 329-1 V3.1.2 (2002-01) 4 4.1 Introduction to end-to-end Quality of Service (QoS) Main QoS parameters influenced by TI PHON systems End-to-end QoS in a TIPHON system is characte
32、rized in the TIPHON QoS documentation under two broad headings: call set-up quality; and call quality. 4.1 .I Call Set-up quality Call set-up quality is mainly characterized by the call set-up time which is perceived by the user as the responsiveness of the service. Call set-up time is the time elap
33、sed from the end of the user interface command by the caller (keypad dialling, E-mail alias typing, etc.) to the receipt by the caller of a meaningful progress information. The present document provides the exact definition of the various call set-up times for use in TIPHON systems, whereas ITU-T Re
34、commendation E.600 5 provides more information on the definition of post-dialling delay in SCN systems. 4.1.2 Call quality Call quality is characterized by the overall transmission quality rating R. Overall transmission quality rating (R) describes the full acoustic-to-acoustic (mouth to ear) qualit
35、y, experienced by a user, for a typical situation using a “standard“ telephony handset. The overall transmission quality rating is calculated using the E-Model (see ITU-T Recommendation G. 107 7). For calculation purposes the use of traditional telephone handsets (see ITU-T Recommendation P.3 10 lo)
36、 at both sides of the connection is assumed. Within the overall transmission quality two major factors contribute to the overall QoS experience of the user of the TIPHON system: end-to-end delay: this mainly impacts the interactivity of a conversation. The measurement is done from the mouth of the s
37、peaker to the ear of the listener; and end-to-end speech quality: this is the one way speech quality as perceived in a non interactive situation. The measurement methodologies for these parameters are specified in TS 101 329-5 4, while the requirements for these parameters with respect to the variou
38、s TIPHON QoS classes are defined in TS 101 329-2 3. TR 101 329-7 (see bibliography) provides guidance on these parameters with respect to the practical design phase of equipment and networks. 4.1.3 Conversational speech quality The conversational quality of a telephone link is influenced by four par
39、ts: Listening quality, the quality of the speech received from the talkers voice at the other side, dominated by noise and speech distortion. Talking quality, the quality of the speech received from the talkers own voice, dominated by echo and sidetone distortion. Interaction quality, the quality as
40、sociated with the alternation of talking and listening, dominated by end-to-end delay and noiselspeech switching. Background noise transmission quality, the quality of the transmission of background noises received from the other side. Note that Background noise transmission quality and Listening qu
41、ality are not independent: the first may or may not have been included in the latter. ETSI 9 ETSI TR 101 329-1 V3.1.2 (2002-01) 4.2 Further QoS parameters In general, Quality of Service (QoS) is determined by a multitude of further QoS parameters; guidance in this field is provided by ITU-T Recommen
42、dation 1.350 9. For the complexity of other QoS parameters it is considered that: they either do not apply to TIPHON systems; or the TIPHON systems have similar influence on those parameters like other telephony systems. 4.3 TIPHON specific QoS relevant factors Examples of TIPHON specific QoS releva
43、nt factors are: number of hops; possible variation of the geographical length of one connection during the talking state; occurrence of congestion; use of prioritization or bandwidth reservation schemes; jitter and jitter buffer behaviour (see clauses 4.3.1 through 4.3.4). TR 101 329-7 (see bibliogr
44、aphy) provides guidance on these factors with respect to the practical design phase of equipment and networks. 4.3.1 Delay Jitter Packetized transmission systems exhibit variable delay in packet delivery time; this is caused by the fact that different packets carrying speech samples of the same tele
45、phone conversation may be transported via distinct routes through the network or queueing of data, voice and other voice streams on the same route: details of this effect depend strongly on the specific mechanisms for transport, queuing or prioritization, which may be implemented in such a system. P
46、ackets which have been transported through a packet based network are collected in a buffer at the receive side. This buffer functions as the instance which re-arranges the timely order of the packets. If the delivery time of a packet exceeds the length of the receive buffer, then this packet “comes
47、 too late“ with respect to the size of this buffer and will be discarded. Hence, the speech carried in this packet is lost for the decoding process. This “packet loss“ impacts speech transmission quality. ETSI 10 Figure 2 shows some measurement result regarding delay jitter: ETSI TR 101 329-1 V3.1.2
48、 (2002-01) duration ofthe pause in the received signal (green) = 670 ms duration ofthe pause in the original send signal (red) = 920 ms L NOTE 1: Red = Original send signal; Green = receive signal (transmitted via the test Set-up). NOTE 2: Due to the selected measurement mode the original send signa
49、l (red) is displayed 500 ms later and reduced by 6 dB in level than in reality. The resulting mean one-way delay lies between 450 ms and 700 ms and is strongly variable. Figure 2: Delay jitter observation Figure 2 shows the observed delay jitter. In the original speech sample (red signal) the pause sequence between the two words has approx. 920 ms duration; after having sent this speech sample over the test set-up the received speech (green signal) has a pause sequence of only 670 ms duration; i.e. the jitter amplitude is 250 ms. 4.3.2 Jitter buffers Jitter bu
