1、 International Telecommunication Union ITU-T Y.1991TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2010) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects IPTV over NGN Terms and definitions for IPTV Recommendation ITU-T
2、 Y.1991 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.200Y.299 Network aspects Y.300Y.399 Interfaces and protocols Y.400Y.499 Number
3、ing, addressing and naming Y.500Y.599 Operation, administration and maintenance Y.600Y.699 Security Y.700Y.799 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.1199 Architecture, access, network capabilities and resource management Y.1200Y.1299
4、 Transport Y.1300Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 IPTV over NGN Y.1900Y.1999NEXT GENERATION NETWORKS Frameworks and functional architecture mod
5、els Y.2000Y.2099 Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Numbering, naming and addressing Y.2300Y.2399 Network management Y.2400Y.2499 Ne
6、twork control architectures and protocols Y.2500Y.2599 Future networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Y.1991 (03/2010) i Recommendation
7、 ITU-T Y.1991 Terms and definitions for IPTV Summary Recommendation ITU-T Y.1991 contains terms and definitions and a framework relevant to providing a general understanding of IPTV. The primary purpose of this Recommendation is to provide a context for the use of certain terms and definitions to av
8、oid misunderstandings in IPTV and IPTV-related activities. History Edition Recommendation Approval Study Group 1.0 ITU-T Y.1991 2010-03-16 13 Keywords CDN, DoS, dPVR, ECG, EPG, ePVR, IPTV, metadata, nPVR, PVR, SCP, TD, VoD. ii Rec. ITU-T Y.1991 (03/2010) FOREWORD The International Telecommunication
9、Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff question
10、s and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on
11、 these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the
12、expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or appli
13、cability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with t
14、he Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicab
15、ility of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implemen
16、t this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means
17、 whatsoever, without the prior written permission of ITU. Rec. ITU-T Y.1991 (03/2010) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Terms and definitions . 1 4 Abbreviations and acronyms 1 5 Conventions 1 6 IPTV definition . 1 7 Terms used in Recommendations related to requirements to support IPTV s
18、ervices 1 8 Terms used in Recommendations related to IPTV architecture . 5 9 Terms used in Recommendations related to performance, QoE, QoS and traffic management 6 10 Terms used in Recommendations related to metadata, terminal devices and home network . 6 11 Terms used in Recommendations related to
19、 secondary distribution 11 12 Terms used in Recommendations related to IPTV security aspects . 12 Bibliography. 15 Alphabetical index . 18 Rec. ITU-T Y.1991 (03/2010) 1 Recommendation ITU-T Y.1991 Terms and definitions for IPTV 1 Scope This Recommendation contains terms and definitions and a framewo
20、rk relevant to providing a general understanding of IPTV. This Recommendation is not simply a compendium of terms and definitions. The primary purpose of this Recommendation is to provide a context for the use of certain terms and definitions to avoid misunderstandings in IPTV and IPTV-related activ
21、ities. Thus, the definitions are arranged in a specific order and certain necessary relationships are illustrated. This Recommendation uses terms and definitions, which are considered particularly suitable and applicable to IPTV work and that have already been defined in published ITU-T Recommendati
22、ons. 2 References None. 3 Terms and definitions Not applicable. 4 Abbreviations and acronyms This Recommendation uses the following abbreviation: IPTV Internet Protocol Television 5 Conventions There are no specific conventions in this Recommendation. 6 IPTV definition 6.1 IPTV b-ITU-T Y.1901: Multi
23、media services such as television/video/audio/text/graphics/ data delivered over IP-based networks managed to support the required level of QoS/QoE, security, interactivity and reliability. 7 Terms used in Recommendations related to requirements to support IPTV services 7.1 accessibility feature b-I
24、TU-T Y.1901: An additional content component that is intended to assist people hindered in their ability to perceive an aspect of the main content. Examples: captions for the hard of hearing, subtitles in various languages, sign-language interpretation video and descriptive audio. 7.2 acquisition b-
25、ITU-T Y.1901: The process of obtaining content by the end-user. NOTE For content with accessibility features, this means that the content will be available in a form that can be used by the end-user. 7.3 application provider b-ITU-T Y-Sup.5: The entity providing IPTV-related user applications. 7.4 a
26、spect ratio b-ITU-T Y.1901: The ratio of the width to the height of a rectangular area, such as the defined display area. 2 Rec. ITU-T Y.1991 (03/2010) 7.5 audio description b-ITU-T Y.1901: This service provides a commentary describing the visual events pertinent to the content and augments the dial
27、og in the content. NOTE Audio description is primarily intended to assist users who are unable to see the video content clearly. The narrative passages fit between the dialogue and other significant audio content so as not to interfere with it. Ideally, the user can control the volume and spatial po
28、sitioning of the audio or derive it from a separate output. 7.6 broadcast b-ITU-T M.60: One-way transmission from one point to two or more other points. 7.7 captions b-ITU-T Y.1901: Captions provide a real-time on-screen transcript of the dialogue as well as any sound effects. NOTE This service can
29、be provided by means of either textual or graphical supplementary content. The captions and the dialogue are usually in the same language. The service is primarily to assist users having difficulty hearing the sound. Ideally, users may have some control over the position and size of the presentation
30、. Different speakers are distinguished, usually by different colours. 7.8 channel b-ITU-T Y.1901: Content formatted as a selectable set of data and transported as part of a data stream. 7.9 channel changing b-ITU-T Y.1901: The act of changing from one channel to another. 7.10 client personal video r
31、ecorder (cPVR) b-ITU-T Y.1901: Same as PVR except that the recording device is located at the end-users premises. 7.11 content aggregator b-ITU-T Y-Sup.5: A player in the IPTV service delivery chain whose role is to aggregate content, e.g., forming a TV bouquet composed of several TV channels. 7.12
32、content segment b-ITU-T Y.1901: A continuous portion of a piece of content, for example, a single topic in a news programme. 7.13 delivery network gateway (DNG) b-ITU-T Y.1901: A device implementing the DNGF. NOTE DNG also is commonly referred to as the residential gateway (RG). 7.14 delivery networ
33、k gateway functions (DNGF) b-ITU-T Y.1901: Set of functions that mediate between the network and service provider domains and the IPTV terminal function (ITF). NOTE A device implementing the DNGF is commonly referred to as the residential gateway (RG) or delivery network gateway (DNG). 7.15 end syst
34、em b-ITU-T Y.1901: A single or set of consumer devices that support IPTV services (e.g., delivery network gateway, display). 7.16 IPTV terminal device b-ITU-T Y.1901: A terminal device which has ITF functionality, e.g., a STB. 7.17 IPTV terminal function (ITF) b-ITU-T Y.1901: The end-user function(s
35、) associated with: a) receiving and responding to network control channel messages regarding session set-up, maintenance, and tear-down; and b) receiving the content of an IP transport from the network and rendering. 7.18 linear TV b-ITU-T Y.1901: A television service in which a continuous stream fl
36、ows in real time from the service provider to the terminal device and where the user cannot control the temporal order in which contents are viewed. 7.19 metadata b-ITU-T Y.1901: Structured, encoded data that describe characteristics of information-bearing entities to aid in the identification, disc
37、overy, assessment, and management of the described entities. NOTE EPG metadata has many applications and may vary in depth from merely identifying the content package title or information to populate an EPG to providing a complete index of different scenes in a movie or providing business rules deta
38、iling how the content package may be displayed, copied, or sold. Rec. ITU-T Y.1991 (03/2010) 3 7.20 middleware b-ITU-T Y.1901: A layer of software between applications and resources, which consists of a set of service enablers that allow multiple functionalities running on one or more devices in an
39、IPTV system to interact across a network. 7.21 mobility b-ITU-T Q.1706: The ability for the user or other mobile entities to communicate and access services irrespective of changes of the location or technical environment. 7.22 multi-channel audio b-ITU-T Y.1901: Audio signal with more than two chan
40、nels. 7.23 network personal video recorder (nPVR) b-ITU-T Y.1901: Same as PVR except that the recording device is located at the service provider premises. 7.24 package b-ITU-T Y.1901: A collection of content components that in some combination (either all or a subset) together provide an end-user e
41、xperience and are intended to be used together. NOTE A package can be instantiated with or without audiovisual content depending on scenarios, in which audiovisual content and package can be tightly associated or can be loosely coupled enough to be handled (generation, delivery, consumption) indepen
42、dently. 7.25 pay per view (PPV) b-ITU-T Y.1901: A TV service where a particular program event (e.g., a hockey match) can be bought separately from any package or subscription. The transmission of the program event is made at the same time to everyone who has ordered it. 7.26 personal video recorder
43、(PVR) b-ITU-T Y.1901: An end-user controlled device that records, stores and plays back multimedia content. PVR is also known as personal digital recorder (PDR). 7.27 picture-in-picture b-ITU-T Y.1901: One program is displayed on the full-seized IPTV TD screen, one or more other programs are simulta
44、neously displayed in inset windows. 7.28 place shifting b-ITU-T Y.1901: A function which allows subscribers to see the content without place limitations. 7.29 push VoD b-ITU-T Y.1901: A TV service where multimedia content is packaged and delivered at the discretion of the service provider to the end
45、-users storage system. 7.30 random access point b-ITU-T Y.1901: A point in the content from which playback can begin. NOTE For example, in MPEG encoding, this would be an I-frame, as opposed to a P-frame or B-frame. 7.31 re-transmission broadcast service b-ITU-T Y.1901: A service in which content is
46、 provided from various broadcasting environments including, but not limited to, terrestrial, satellite and cable, and re-transmitted into IP network simultaneously or otherwise. 7.32 service b-ITU-T Y.1901: A set of functionalities enabled by a provider for end-users. NOTE Example provisioned functi
47、onalities include IP connectivity with managed quality of service, video-on-demand. 7.33 service provider b-ITU-T M.1400: A general reference to an operator that provides telecommunication services to customers and other users either on a tariff or contract basis. A service provider may or may not o
48、perate a network. A service provider may or may not be a customer of another service provider. NOTE Typically, the service provider acquires or licenses content from content providers and packages this into a service that is consumed by the end-user. 7.34 sign language interpretation b-ITU-T Y.1901:
49、 A video service showing an interpreter who uses hand gestures and facial expression to convey the main audio content and dialogue to sign language and lip readers. 4 Rec. ITU-T Y.1991 (03/2010) NOTE This service comes in the form of supplementary video content, usually smaller in image size to that of the main video content. Ideally, the user can control the position, size and background properties (solid or transparent and the colour, if solid). It is of suff
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