1、 ATIS-0800004 A FRAMEWORK FOR QOS METRICS AND MEASUREMENTS SUPPORTING IPTV SERVICES The Alliance for Telecommunication Industry Solutions (ATIS) is a technical planning and standards development organization that is committed to rapidly developing and promoting technical and operations standards for
2、 the communications and related information technologies industry worldwide using a pragmatic, flexible and open approach. Over 1,100 participants from more than 350 communications companies are active in ATIS 23 industry committees and its Incubator Solutions Program. NOTE - The users attention is
3、called to the possibility that compliance with this standard may require use of an invention covered by patent rights. By publication of this standard, no position is taken with respect to whether use of an invention covered by patent rights will be required, and if any such use is required no posit
4、ion is taken regarding the validity of this claim or any patent rights in connection therewith. ATIS-0800004, A Framework for QoS Metrics and Measurements Supporting IPTV Services Is an ATIS standard developed by the Quality of Service Metrics (QoSM) Task Force under the ATIS IPTV Interoperability F
5、orum (IIF). Published by Alliance for Telecommunications Industry Solutions 1200 G Street, NW, Suite 500 Washington, DC 20005 Copyright 2006 by Alliance for Telecommunications Industry Solutions All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieva
6、l system or otherwise, without the prior written permission of the publisher. For information contact ATIS at 202.628.6380. ATIS is online at . Printed in the United States of America. ATIS-0800004 ATIS Standard on A Framework for QoS Metrics and Measurements Supporting IPTV Services Secretariat All
7、iance for Telecommunications Industry Solutions Approved November 2006 Abstract This document provides an initial industry consensus view of scope, definitions, and tools to support the creation of IPTV QoS metrics and measurements within ATIS IPTV Interoperability Forum (IIF). i ATIS-0800004 Contri
8、butors Kevin Schneider, ADTRAN Donald Crowe, Alcatel-Lucent Rick Townsend, Alcatel-Lucent Rajesh Jagannathan, Alcatel-Lucent Randy Sharpe, Alcatel-Lucent Al Morton, AT DASHED LINES ARE TRANSACTIONAL, FILE TRANSFER OR PHYSICAL21 FIGURE 10: FULL QOS MEASUREMENT MODEL .24 FIGURE 11: CONTENT QUALITY IMP
9、ACTS.25 FIGURE 12: MEDIA STREAM QUALITY IMPACTS.26 FIGURE 13: TRANSMISSION QUALITY IMPACTS 27 FIGURE 14: TRANSACTION QUALITY IMPACTS .28 FIGURE 15: EXAMPLE PROTOCOL STACK .29 FIGURE 16: TR-69 CPE WAN PROTOCOL34 FIGURE 17: DSL FORUM CPE MANAGEMENT SPECIFICATIONS .35 FIGURE 18: EXAMPLE SERVICE ARCHITE
10、CTURE OF IPTV VIDEO SERVICE.51 FIGURE 19: EXAMPLE OF IGMP SERVICE ARCHITECTURE OF IPTV VIDEO SERVICE .52 FIGURE 20: EXAMPLE OF IGMP CALL FLOW FOR SELECTING CHANNEL 2 AND CHANGE TO CHANNEL 3 53 FIGURE 21: EXAMPLE SERVICE ARCHITECTURE OF IPTV VIDEO ON DEMAND SERVICE 55 FIGURE 22: EXAMPLE OF RTSP FOR T
11、RICK FEATURES.57 iv ATIS-0800004 TABLE OF TABLES TABLE 1: METRIC DEFINITION.9 TABLE 2: MEASUREMENT POINTS FOR CONTENT QUALITY25 TABLE 3: MEASUREMENT POINTS FOR MEDIA STREAM QUALITY .26 TABLE 4: MEASUREMENT POINTS FOR TRANSMISSION QUALITY LAYER27 TABLE 5: MEASUREMENT POINTS FOR TRANSACTION QUALITY 28
12、 TABLE 6: IMPACT OF ENCRYPTION .31 TABLE 7: DSL FORUM QOE MAP.44 TABLE 8: SUBJECTIVE EVALUATION SCALE .48 v ATIS STANDARD ATIS-0800004 ATIS Standard on A Framework for QoS Metrics and Measurements Supporting IPTV Services 1 INTRODUCTION 1.1 Overview/background This document provides an initial indus
13、try consensus view of scope, definitions, and tools to support the creation of IPTV Quality of Service (QoS) metrics and measurements within ATIS IIF. Chapter 2 provides a conceptual framework, including definitions of Quality of Experience (QoE), scope of the ATIS IIF Quality of Service Metrics (Qo
14、SM) Task Force (TF), types of metrics and measurements, and some examples. Chapter 3 provides a QoS metric measurement model, a discussion on protocol stack views, and use cases, which can be used for the creation of metrics and measurements. Appendix A describes standards work that is relevant for
15、IPTV metrics and measurements. Appendix B provides background information on Quality of Service in the industry. Appendix C provides a summarized view of the activities in DSL Forum WT-126. Appendix D describes video quality impairments. Appendix E describes perceptual video quality. Appendix F incl
16、udes an informative example of two IPTV services, linear/broadcast TV and VoD, analyzed using concepts introduced in this framework WT. 1.2 Goal The Framework document will serve as a basis for definitions of Quality of Service (QoS)/Quality of Experience (QoE) related to different segments of the n
17、etwork, different service instances or invocations, network architectures/technologies utilized, and modes of service. In that regard, the Framework document will provide a basic overview and concepts related to: Measurement model and measurement points. Quality layers, protocol stack view, and use
18、cases. Metrics - types, characteristics, definitions. QoS/QoE Model. Measurement practices and methodologies. Time and Frequency synchronization requirements for ensuring QoS/QoE and enabling metrics measurement. The goal of the Framework document is to provide concepts and definitions that will be
19、agnostic to architecture, network topology, network technology, systems, devices, and business model variations. However, the concepts and definitions described could be adapted to any of these variations in an effective manner and for a universal definition of QoE/QoS experienced by the end user. I
20、t is also the intent of the Framework document to utilize available definitions and content from other standards bodies as applicable. 1 ATIS-0800004 1.3 Purpose The Framework document provides concepts, models, and definitions that are used as the foundation content for further definitions and desc
21、riptions of IPTV QoS/QoE metrics, models, tools, and techniques for measurements of QoS/QoE for IPTV services. The Framework document also relies on models, definitions, and service descriptions documented in the ATIS-0800002, IIF Architecture Requirements document, and ATIS-0800001, IIF Digital Rig
22、hts Management (DRM) Requirements document. 1.4 Scope The scope of the framework is to set out a common conceptual framework and definitions that can be applied to all network types, service types, and service instances as defined in other IIF documents. IPTV services are defined in ATIS-0800002 as
23、follows: IPTV is defined as a managed service providing the secure and reliable delivery to customers of entertainment video and related services. This document specifies the general QoS framework upon which the definition of quality metrics and measurement methods are based. This is accomplished by
24、 use of a Measurement Model and a multi-layer measurement concept describing the IPTV service delivery framework from a logical perspective. This document identifies reference points and defines metric concepts that may be used to measure the quality of the video applications and other aspects of se
25、rvice delivery. The framework document also recognizes that multiple service providers may be involved in the service delivery and interprovider or interdomain in QoS measurement will be considered within the scope. The model used for this working text applies to the end-to-end IPTV service and netw
26、ork delivery chain including content provider, service provider, network provider, and customer domains. The four communicating domains as described in the ATIS 0800002, IPTV Architecture Requirements, are shown in the following figure: Figure 1: IPTV Logical Domains1Specific measurement points may
27、be specified within and at the boundary of each of these domains. Metrics may also describe the performance of any layer of the protocol stack that affect the end-to-end video application performance. 1IPTV Architecture Requirements, ATIS 0800002, Figure 2 2 ATIS-0800004 1.5 Interoperability Interop
28、erability reduces the complexity of service design and enables a service provider to deliver a universal service regardless of the infrastructure utilized. The interoperability sphere is bounded by the consideration that all elements requiring interoperability with each other must support IPTV servi
29、ce as defined in ATIS-0800002, and is defined within the framework of the QoSM TF to have the following three characteristics: consistency, data collection, and reportability. 1.5.1 Consistency Interoperability in the context of the QoSM TF is focused upon consistency of measurement - i.e., the meas
30、urement of a given metric will yield consistent results regardless of the type of measurement instrumentation chosen. Further, the measurement of a given metric across multiple domains and service provider networks must be consistent in terms of metric definition, measurement methodology, and accura
31、cy. A metrics definition should be consistent throughout. Furthermore, when comparing metric data over a time period or across different measurement points, the same measurement methodology must be used for measurement. The accuracy of a particular measurement must meet the minimum guidelines define
32、d in the Working Texts (WT), including such definitions to be compliant. 1.5.2 Data collection The measurement point and the system involved must support the instrumentation required to perform the measurement of a metric. Such instrumentation may support communication messages/measurement commands
33、that may be sent from a different equipment to initiate and report data collection. 1.5.3 Reportability Reportability of metrics data collected must be supported by the measurement equipment, measurement points, tools, and mechanisms. Metrics defined at various test points must be reportable - i.e.,
34、 the instrumentation must support the communication of the data collected to another system that may process it further. The format of such collected data is not within the scope of the QoSM TF. 1.5.4 Interoperability and Other Standards A principal method for formulation of definitions and specific
35、ations by the QoSM TF is to rely on accepted standards or emerging standards from other standards bodies. This is intended to ensure that there is consistency, and reduces the complexity of delivering IPTV services. Interoperability as it may apply to the QoSM TF will be defined with the help of suc
36、h generally accepted or developing standards. In the definition of all aspects of QoS/E metrics, special attention/emphasis will be placed on ensuring that the QoS/QoE characterizations are universal and applicable across a diverse set of implementations that may be employed to provide the same func
37、tion. Also, any metrics, mechanisms, models, tools, and methodologies that are specified operate consistently across the network. 3 ATIS-0800004 1.6 Terminology 1.6.1 Glossary Active Measurements Active measurements use dedicated test traffic, to collect performance info that is representative of cu
38、stomers traffic. They are usually taken at two or more reference points. Active measurements use dedicated test “signals“ and may use either test stimuli or synthetic traffic Passive Measurements Passive measurements always use live customer traffic, and fall into two categories: single-point passiv
39、e measurements and two-point passive measurements Single-point Passive Measurements Measurements collected from network elements, such as link utilization or packet discards. Two-point Passive Measurements Measurements that match data at two points such as packets observed at two different points in
40、 the network. Data collected similar to active measurements, but using live traffic instead of injecting test signals. Use Case A use case is an external view of a system that represents an action or sequence of actions the user might perform in order to complete a task. Measurement Instrumentation
41、Measurement instrumentation refers to the ability of a device to support appropriate measurements. This device or equipment may be a dedicated measurement system or a device or equipment that is involved in the end-to-end IPTV service delivery, such as an Interactive Terminal Function (ITF). Quality
42、 of Experience (QoE) Describe the users experience. QoE can be broadly grouped: i.e., picture QoE, transaction QoE, audio QoE, and multimedia QoE. QoE may be calculated or estimated numerically using sets of QoE indicators and/or QoS metrics. Quality of Experience (QoE) Indicators Individual perform
43、ance indicators that can be experienced by a user. Include video indicators such as picture error blocks, transaction indicators such as channel change delay, audio indicators, and multimedia indicators. Quality of Service (QoS) Metrics Measures of technical performance. Includes network QoS metrics
44、, such as packet loss, and application QoS metrics, such as VoD server errors. 1.6.2 Acronyms ACS Auto-Configuration Server CPE Customer Premise Equipment DNG Delivery Network Gateway DRM Digital Rights Management DSL Digital Subscriber Line DVB Digital Video Broadcasting (Project) FEC Forward Error
45、 Control HNED Home Network End Device IETF Internet Engineering Task Force IGMP Internet Group Management Protocol IIF IPTV Interoperability Forum IPG Interactive Program Guide IPPM IETF IP Performance Metrics Working Group IPTV Internet Protocol Tele-Vision ITF Interactive Terminal Function ITU-T I
46、nternational Telecommunication Union Telecommunication Standardization Sector KBPS kilobits per second MPEG Motion Picture Experts Group OSI Open Systems Interconnect PIP Picture In Picture 4 ATIS-0800004 PON Passive Optical Networks PPV Pay Per View PQoS Payload Quality of Service PSD Power Spectra
47、l Density QoE Quality of Experience QoS Quality of Service QoSM Quality of Service Metrics RPC Remote Procedure Call RTCP Real-Time Control Protocol RTP Real-Time Protocol RTSP Real-Time Streaming Protocol SA Service Assurance SLA Service Level Agreement SNMP Simple Network Management Protocol SP Se
48、rvice Provider STB Set Top Box VHE Video Head End VHO Video Hub Office VQEG Video Quality Experts Group VSO Video Serving Office VOD Video On Demand UDP User Datagram Protocol XML eXtended Markup Language 1.7 References 1.7.1 Normative References The following standards contain provisions that, thro
49、ugh reference in this text, constitute provisions of this report. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. 1.7.1.1 ATIS: 1 T1.801.02-1996, Digital Transport of Video Teleconferencing/Video Telephony Signals Performance Terms, Definitions and Examples. 2 ATIS-0800002, IPTV Architecture Requirements, ATIS-IIF, May 16, 2006. 3 ATI
