1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T F.734 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (10/2014) SERIES F: NON-TELEPHONE TELECOMMUNICATION SERVICES Audiovisual services Definitions, requirements and use cases for telepresence systems Recommendation ITU-T F
2、.734 ITU-T F-SERIES RECOMMENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES TELEGRAPH SERVICE Operating methods for the international public telegram service F.1F.19 The gentex network F.20F.29 Message switching F.30F.39 The international telemessage service F.40F.58 The international telex service
3、 F.59F.89 Statistics and publications on international telegraph services F.90F.99 Scheduled and leased communication services F.100F.104 Phototelegraph service F.105F.109 MOBILE SERVICE Mobile services and multidestination satellite services F.110F.159 TELEMATIC SERVICES Public facsimile service F.
4、160F.199 Teletex service F.200F.299 Videotex service F.300F.349 General provisions for telematic services F.350F.399 MESSAGE HANDLING SERVICES F.400F.499 DIRECTORY SERVICES F.500F.549 DOCUMENT COMMUNICATION Document communication F.550F.579 Programming communication interfaces F.580F.599 DATA TRANSM
5、ISSION SERVICES F.600F.699 AUDIOVISUAL SERVICES F.700F.799 ISDN SERVICES F.800F.849 UNIVERSAL PERSONAL TELECOMMUNICATION F.850F.899 HUMAN FACTORS F.900F.999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T F.734 (10/2014) i Recommendation ITU-T F.734 Definitions, re
6、quirements and use cases for telepresence systems Summary Recommendation ITU-T F.734 provides definitions, use cases and functional requirements for telepresence systems. Telepresence is an interactive audio-visual communications experience between remote locations, where the users enjoy a strong se
7、nse of realism and presence between participants by optimizing a variety of attributes. A telepresence system is a set of functions, devices and network elements which are able to capture, deliver, manage and render multiple high quality interactive audio and video signals in a telepresence conferen
8、ce to deliver a telepresence experience. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T F.734 2014-10-14 16 11.1002/1000/12216 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations uniq
9、ue ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T F.734 (10/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunica
10、tion Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly
11、(WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on 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 fa
12、ll within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this R
13、ecommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language
14、 such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recom
15、mendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of app
16、roval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB
17、 patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T F.734 (10/2014) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 3.1
18、Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 3 6 Scenarios and use cases 3 6.1 Use case 1: Symmetric point-to-point meeting 3 6.2 Use case 2: Asymmetric point-to-point meeting 3 6.3 Use case 3: Multipoint meeting 4 6.4 Use case 4
19、: Presentation . 4 6.5 Use case 5: Heterogeneous systems . 5 6.6 Use case 6: Multipoint education usage . 6 6.7 Use case 7: Multipoint multiview (virtual space) . 6 6.8 Use case 8: Legacy interworking . 7 6.9 Use case 9: Telemedical use case . 7 7 User experience requirements . 8 8 Control Functiona
20、l requirements 10 8.1 Call control functions . 10 8.2 Media control functions 10 8.3 Conference control functions . 11 8.4 Collaboration functions 12 8.5 Other functions . 12 9 Interoperability requirements 13 9.1 Interoperation with traditional systems 13 9.2 Interoperation between telepresence sys
21、tems . 13 10 Network requirements 13 11 Security requirements . 14 Bibliography. 15 Rec. ITU-T F.734 (10/2014) 1 Recommendation ITU-T F.734 Definitions, requirements and use cases for Telepresence Systems 1 Scope This Recommendation provides definitions, use cases and functional requirements for tel
22、epresence systems. A telepresence system is a set of functions, devices and network elements which are able to capture, deliver, manage and render multiple high quality interactive audio and video signals in a telepresence conference. An appropriate number of devices (e.g., cameras, screens, loudspe
23、akers, microphones, codecs, multipoint control units (MCUs), PCs) and environmental characteristics are used to establish telepresence. Specific requirements include those for: User experience Control, including: Call control functions Media control functions Conference control functions Collaborati
24、on functions Inter-operability Network Security The requirements in this Recommendation relate to functions that a telepresence system is required to support. That is, a telepresence system should be able to provide the functions in its design or by utilizing existing mechanisms. Recommended require
25、ments do not mandate the implementation or the deployment of a particular function. For example: Whilst a telepresence system should support mechanisms for assured QoS, it may be deployed in a network where QoS is not assured. Unless the requirement mentions a specific function or device, the requir
26、ements listed in this Recommendation apply to a telepresence system as a whole. The inclusion of a requirement does not necessarily mean that new protocols need to be developed to meet it. For example whilst there may be a requirement to support QoS for telepresence, ultimately existing QoS mechanis
27、ms may be utilized for this. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other refe
28、rences are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference
29、 to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T H.243 Recommendation ITU-T H.243 (2005), Procedures for establishing communication between three or more audiovisual terminals using digital channels up to 1920 kbit/s. ITU-T
30、H.323 Recommendation ITU-T H.323 (2009), Packet-based multimedia communications systems. 2 Rec. ITU-T F.734 (10/2014) 3 Definitions 3.1 Terms defined elsewhere None. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 actual size: A rendered figure in a di
31、splay is the same size as if the person is in the room. 3.2.2 capture: Media acquired from a capture device such as a camera or microphone or constructed from other media (for example combining the signals from several microphones). 3.2.3 endpoint: For the purposes of this Recommendation an endpoint
32、 is a device representing the logical point of final termination through receiving, decoding and rendering, and/or the point of origination through capturing, encoding, and sending of media streams, e.g., an H.323 terminal. 3.2.4 gaze awareness: Awareness of gaze direction of persons by watching the
33、ir eyes, head and body position. There is awareness of both direct gaze and averted gaze. Direct gaze is the perception of persons looking at each other directly and simultaneously. Averted gaze is the perception that other persons are looking at someone/something else in the environment. 3.2.5 gaze
34、 direction: The vector positioned along the visual axis, pointing from the fovea of the looker through the centre of the pupil to the looked at spot. 3.2.6 eye contact: Mutual direct-gaze between two persons communicating. 3.2.7 natural response: Interaction between local and remote participants tha
35、t is not impeded by the delay introduced by the telepresence system. 3.2.8 telepresence: An interactive audio-visual communications experience between remote locations, where the users enjoy a strong sense of realism and presence between participants by optimizing a variety of attributes such as aud
36、io and video quality, eye contact, gaze awareness, body language, spatial audio, coordinated environments and natural image size. 3.2.9 telepresence-enabled audio endpoint: An audio-only endpoint that supports telepresence endpoint functions/signalling and delivers a strong sense of presence and rea
37、lism through the use of technologies such as wider bandwidth speech and spatial audio (e.g., stereo telephony). 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: 3D Three Dimensional FECC Far End Camera Control HDTV High Definition Television IP Internet
38、 Protocol IPv4 Internet Protocol Version 4 IPv6 Internet Protocol Version 6 MCU Multipoint Control Unit NAT Network Address Translation PC Personal Computer QoE Quality of Experience Rec. ITU-T F.734 (10/2014) 3 QoS Quality of Service SIP Session Initiation Protocol 5 Conventions In this Recommendat
39、ion, the following conventions apply. The keywords “is required to“ indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. The keywords “is recommended“ indicate a requirement which is recommended but w
40、hich is not absolutely required. Thus this requirement need not be present to claim conformance. The keywords “can optionally“ indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendors implementation mu
41、st provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. 6 Scenarios and use cases The use cases in this clause illustrate various telep
42、resence configurations for the purposes of identification of requirements. These configurations apply to scenarios where telepresence is in use and do not include legacy systems (i.e., non-telepresence systems) unless specifically indicated in the use case. They do not imply the need for mandatory s
43、upport of any particular configurations. For simplicity, the use cases below assume that each camera and microphone produces a single capture, and that each display renders a single capture. In actual implementations, the relationship between captures and transducers can be more complex. For example
44、, a pair of microphones may be mixed to monophonic sound (creating one capture from two transducers). Alternatively, the same microphone arrangement can produce three captures (left, right, and centre), creating three captures from the same two transducers. 6.1 Use case 1: Symmetric point-to-point m
45、eeting In this case, the two sites have an identical number of screens, with cameras having fixed fields of view, and one camera for each screen. The number of screens or cameras is not relevant so long as both sites have the same number. The sound type is the same at each end. Figure 1 illustrates
46、the use case. Figure 1 Use case 1: Symmetric point-topoint meeting For further information see clause 3.1 of b-IETF RFC 7205. 6.2 Use case 2: Asymmetric point-to-point meeting In this case, each site has a different number of screens and cameras. The number of screens or cameras is not relevant so l
47、ong as both sites have a different number. Figure 2 illustrates the use case. For further information see clause 3.2 of b-IETF RFC 7205. 4 Rec. ITU-T F.734 (10/2014) Figure 2 Use case 2: Asymmetric point-to-point meeting 6.3 Use case 3: Multipoint meeting In this use case of a multipoint telepresenc
48、e conference, there are more than two sites participating. Figure 3 illustrates the use case. For further information see clause 3.3 of b-IETF RFC 7205. Figure 3 Use case 3: Multipoint meeting 6.4 Use case 4: Presentation This use case builds on the previous use cases. In addition to the video and a
49、udio streams showing the participants, additional streams are used for presentations. For example, the additional stream may be for content sources such as: document cameras, electronic whiteboards, computer (e.g., a laptop computer) or instant messaging. Figure 4 illustrates the use case. The presentation viewgraphs can be distributed to remote endpoints either by adding new streams or by embedding (or switching) viewgraphs into an existing video stream. For further information see clause 3.4 of
