1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU F.703 (1 1/2000) SERIES F: NON-TELEPHONE TELECOMMUNICATION S E RV I CES Audiovisual services Multimedia conversational services ITU-T Recommendation F.703 (Formerly CCITT Recommendation) ITU-T F-SERIES RECOMM
2、ENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES II TELEGRAPH SERVICE Operating methods for the international public telegram service The gentex network Message switching The international telemessage service The international telex service Statistics and publications on international telegraph se
3、rvices Scheduled and leased communication services Phototelegraph service Mobile services and multidestination satellite services TELEMATIC SERVICES Public facsimile service Teletex service Videotex service General provisions for telematic services MOBILE SERVICE MESSAGE HANDLING SERVICES DIRECTORY
4、SERVICES DOCUMENT COMMUNICATION Document communication Programming communication interfaces DATA TRANSMISSION SERVI CES F. l-F. 19 F.20-F.29 F.30-F.39 F.40-F.58 F.59-F.89 F .90-F .99 F. 100-F. 104 F. 105-F. 1 O9 F.110-F.159 F. 160-F. 199 F.200-F.299 F.300-F.349 F.350-F.399 F.400-F.499 F.500-F.549 F.
5、550-F.579 F.580-F.599 F.600-F.699 ISDN SERVICES F.800-F.849 UNIVERSAL PERSONAL TELECOMMUNICATION HUMAN FACTORS F.850-F.899 F.900-F.999 For further details, please re$m to the list of ITD-T Recommendations. ITU-T Recommendation F.703 Multimedia conversational services Summary The purpose of this ITU-
6、T Recommendation is to define the Generic Multimedia Conversational Service and to describe their general features, regardless of the network environment in which these services are provided. These services allow conversational communication between two users in two different locations. The Generic
7、Multimedia Conversational Services are one of the generic service types identified in ITU-T Recommendation F.700, and their description follows the methodology described therein. The user requirements for the various applications supported by the service are translated into generic service specifica
8、tions, independent of the constraints of specific implementations. Thus this ITU-T Recommendation sets out the requirements that will satisfy the users needs and allow proper intercommunication on an international basis of services offered by different providers and of equipments rom different manuf
9、acturers. Various instances (profiles) of this generic service are considered here with a network independent view. Specific service descriptions for each network will be issued in other Recommendations. The detailed technical specifications of the terminal, network and protocol aspects for each of
10、them are described in dedicated ITU-T Recommendations of the H.200, H.300, H.400 series. Along with the F.700 methodology, the description relies on the media components and the communication tasks described respectively in Annexes A and B of ITU-T Recommendation F.700 together with the middleware s
11、ervice elements in Annexes C for control and processing functions. These are service independent modular communication capabilities. Source ITU-T Recommendation F.703 was prepared by ITU-T Study Group 16 (2001-2004) and was approved under the World Telecommunication Standardization Assembly Resoluti
12、on 1 procedure on 17 November 2000. ITU-T F.703 (11/2OOO) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is respons
13、ible 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 (WTSA), which meets every four years, establishes the topics for study by the ITU
14、-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T 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
15、 prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility tha
16、t the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The 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 Recomme
17、ndation development process. As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest informati
18、on and are therefore strongly urged to consult the TSB patent database. o ITU 2001 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing fi-om the ITU.
19、11 ITU-T F.703 (11/2OOO) CONTENTS 1 2 3 3.1 3.2 4 4.1 4.2 4.3 4.4 4.5 4.6 5 5.1 5.2 5.3 6 6.1 6.2 6.3 Scope . Definition References and terminology Terminology References . Description General description . Functional model Configuration Terminal aspects . Applications Supplementary services . Stati
20、c aspects . Service level 5.1.1 General aspects ofthe service 5.1.2 Quality of service . 5.1.3 Security aspects . 5.1.4 General charging principles . Communication task level 5.2.1 Communication tasks used for the service 5.2.2 Quality of service related to the communication tasks Media component le
21、vel . Media components used for the service . Quality of service related to the media components 5.3.1 5.3.2 Dynamic aspects . Activation phase . 6.1.1 Provision. withdrawal 6.1.2 Call establishment Communication phase . 6.2.1 Call Set-up 6.2.2 Change of communication mode . 6.2.3 Conference calls .
22、 6.2.4 Audio muting and video inhibition 6.2.5 Access to other services . Termination phase . ITU-T F.703 (11/2OOO) Page 1 1 4 4 4 5 5 5 6 6 6 6 6 6 7 7 7 8 8 8 8 8 8 8 9 . 111 Page 7 Service profiles . 7.1 Different types of Multimedia Conversational Services . 7.2 List of service profiles 8 Intenv
23、orking and intercommunication 8.1 General 8.2 Intercommunication with a telephone terminal 8.3 Videophone and other multimedia conference terminals . 8.3.1 Audiographic conference and videophone terminals . 8.3.2 Videoconference and videophone terminals 8.3.3 Communication with a facsimile terminal
24、. 8.3.4 Text telephone intenvorking 8.3.5 Total Conversation intenvorking . 11 11 11 11 11 11 11 11 11 iv ITU-T F.703 (11/2000) Introduction The purpose of this ITU-T Recommendation is to define the Generic Multimedia Conversational Service and to describe their general features, regardless of the n
25、etwork environment in which these services are provided. These services allow conversational communication between two users in two different locations. The Generic Multimedia Conversational Services are one of the generic service types identified in ITU-T Recommendation F.700, and their description
26、 follows the methodology described therein. The user requirements for the various applications supported by the service are translated into generic service specifications, independent of the constraints of specific implementations. Thus this ITU-T Recommendation sets out the requirements that will s
27、atisfy the users needs and allow proper intercommunication on an international basis of services offered by different providers and of equipments rom different manufacturers. Various instances (profiles) of this generic service are considered here with a network independent view. Specific service de
28、scriptions for each network will be issued in other Recommendations. The detailed technical specifications of the terminal, network and protocol aspects for each of them are described in dedicated ITU-T Recommendations of the H.200, H.300, H.400 series. Along with the F.700 methodology, the descript
29、ion relies on the media components and the communication tasks described respectively in Annexes A and B of ITU-T Recommendation F.700. These are service independent modular communication capabilities. ITU-T F.703 (11/2OOO) V ITU-T Recommendation F.703 Multimedia conversational services 1 Scope The
30、purpose of this ITU-T Recommendation is to define the Generic Multimedia Conversational Service and to describe their general features, regardless of the network environment in which these services are provided. These services allow conversational communication between two users in two different loc
31、ations. The Generic Multimedia Conversational Services are one of the generic service types identified in ITU-T Recommendation F.700, and their description follows the methodology described therein. The user requirements for the various applications supported by the service are translated into gener
32、ic service specifications, independent of the constraints of specific implementations. Thus this ITU-T Recommendation sets out the requirements that will satisfy the users needs and allow proper intercommunication on an international basis of services offered by different providers and of equipments
33、 rom different manufacturers. Various instances (profiles) of this generic service are considered here with a network independent view. Specific service descriptions for each network will be issued in other Recommendations. The detailed technical specifications of the terminal, network and protocol
34、aspects for each of them are described in dedicated ITU-T Recommendations of the H.200, H.300, H.400 series. Along with the F.700 methodology, the description relies on the media components and the communication tasks described respectively in Annexes A and B of ITU-T Recommendation F.700. These are
35、 service independent modular communication capabilities. 2 Definition The Multimedia Conversational Services provide real time transmission of voice together with motion video andor various types of multimedia information between two users in two different locations. The information exchanged may in
36、clude all information types. When moving pictures are present, their quality should be at least sufficient for the adequate representation of the fluid movements of a person displayed in head and shoulders view. NOTE - The smoothness of the movements in the reproduced picture is essentially dependen
37、t on the amount of motion with respect to the transfer rate and compression scheme of transmitted picture information. The above requirements are supposed to be met under such conditions where the amount of motion is limited or the throughput is high enough not to impair the received picture. Degrad
38、ation may appear as increased blurring, jerkiness andor various artefacts in the reproduced picture. The media components used are described in the Annexes A of ITU-T Recommendation F.700 on Audiovisualkultimedia Services. Media component Audio (Annex A. 1) is usually present, together with one or m
39、ore of the media components Video (Annex A.2), Text (AnnexA.3), Graphics (Annex A.4), Still Pictures (Annex AS). 3 References and terminology 3.1 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of thi
40、s Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the ITU-T F.703 (11/2OOO) 1 most recent edition of t
41、he Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - ITU-T Recommendation F.700 (2000), Framework Recommendation for audiovisual/multimedia services. - ITU-T Recommendation F.702 (1 996), Multimedia conference services. -
42、 ITU-T Recommendation G. 1 14 (2000), One-way transmission time. - CCITT Recommendation G.711 (1988), Pulse code modulation (PCM) of voice frequencies. - CCITT Recommendation G.722 (1988), 7 WTz audio-coding within 64 kbit/s. - ITU-T Recommendation T. 120 (1 996), Data protocols for multimedia confe
43、rencing. - ITU-T Recommendation T. 140 (1998), Protocol for multimedia application text conversation. ITU-T H-series Recommendations - Supplement 1 (1999), Application proJile - Sign language and lip-reading real-time conversation using low bit-rate video communication. - 3.2 Terminology 3.2.1 Colla
44、borative Document Handling service (CDH): A service that provides bidirectional transfer of data between two or more locations so that users are able to work on a common document, for drafting or amending it collectively. 3.2.2 communication modes: A communication mode is defined by the various chan
45、nels supporting the media used for the service. Changes in communication mode may occur during the course of the call, in order to set up or eliminate one of the media, or to change its quality level and thus the bit-rate allocation. It may be used for instance to temporarily add a channel for trans
46、mitting still pictures. 3.2.3 Multipoint Conference Unit (MCU): Equipment that provides multipoint connections among three or more conference rooms. 3.2.4 muting: Preventing sound to be transmitted from a terminal equipment. 3.2.5 videoconference service: An audiovisual conference service providing
47、bidirectional real- time transfer of voice and motion video between groups of users in two or more separate locations. Although the audio and motion video informations are the essential part of the service, other types of information, such as high resolution still pictures, text or graphics may also
48、 be exchanged. 3.2.6 videophone service: An audiovisual conversational service providing bidirectional symmetric real-time transfer of voice and motion video between two locations. The minimum requirement is that under normal conditions the picture information transmitted is sufficient for the adequ
49、ate representation of fluid movements of a person displayed in head and shoulders view. 3.2.7 total conversation service: An audiovisual conversation service providing bidirectional symmetric real-time transfer of motion video, text and voice between users in two or more locations. 3.2.8 text telephone service: An audiovisual conversation service providing bidirectional real time transfer of text and optionally audio between users in two locations. Audio may be transmitted alternating with text or simultaneously with text. 2 ITU-T F.703 (11/2OOO) 4 Description 4.1 General description
