ITU-T H 282-1999 Remote Device Control Protocol for Multimedia Applications Series H Audiovisual and Multimedia Systems Infrastructure of Audiovisual Services - Related Systems Asp.pdf

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1、 - - STD-ITU-T RECMN H.282-ENGL 1999 D 4862591 Ob65905 O12 MI INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF TU H.282 (05/99) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Infrastructure of audiovisual services - Related systems aspects Remote device control p

2、rotocol for multimedia applications ITU-T Recommendation H.282 (Previously CCITT Recommendation) - . STD-ITU-T RECMN H.282-ENGL 3999 9 48b2593 0bb590b T59 W ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS Characteristics of transmission channels used for other than telephone purpos

3、es Use of telephone-type circuits for voice-frequency telegraphy Telephone circuits or cables used for various types of telegraph transmission or simultaneous transmission Telephone-type circuits used for facsimile telegraphy Characteristics of data signals CHARACTERISTICS OF VISUAL TELEPHONE SYSTEM

4、S INFRASTRUCTURE OF AUDIOVISUAL SERVICES General Transmission multiplexing and synchronization Systems aspects Communication procedures Coding of moving video H. I O-H. 19 H.20-H .29 H.30-H.39 H.40-H.49 H.50-H.99 H. I OO-H. 199 H .200-H .2 I 9 H.220-H.229 H.230-H.239 H.240-H.259 H .260-H .279 H.280-

5、H.299 Systems and terminal equipment for audiovisual services Supplementary services for multimedia H.300-H.399 H.450-H.499 For further details, please refir to ITU-T List of Recommendations. ._. . . STD-ITU-T RECMN H.282-ENCL 3999 W 48b259L 0bb5907 995 ITU-T RECOMMENDATION H.282 REMOTE DEVICE CONTR

6、OL PROTOCOL FOR MULTIMEDIA APPLICATIONS Summary This Recommendation describes the core services and protocol for performing configuration and control of a remote device during a multimedia conference. A number of standard devices are defined allowing a node to model a peripheral device such as for e

7、xample a camera, microphone, VCR or slide projector. This Recommendation also allows the modelling of non-standard devices. This model is presented to the other nodes in the conference to allow these nodes to perform remote control. This Recommendation does not speciQ the use of a particular transpo

8、rt protocol. Recommendation T. 136 describes its application using T. 120 as the transport protocol. Recommendation H.283 describes its application using the RDC logical channel transport Future Recommendations may describe its application using other protocols. I established using H.245. Source ITU

9、-T Recommendation H.282 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 27th of May 1999. Recommendation H.282 (05/99) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of te

10、lecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The 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 Wo

11、rld Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-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 lai

12、d down in WTSC Resolution No. 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation the term recognized operating agency (ROA) includes any individual, company, corporat

13、ion or governmental organization that operates a public correspondence service. The terms Administration, ROA and public correspondence Fe defined in the Constitution of the ITU (Geneva, 1992). INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementatio

14、n 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 Recommendation development process. As

15、 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 information and are therefore strongly u

16、rged to consult the TSB patent database. O ITU 1999 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 from the ITU. 11 Recommendation H.282 (0999) -

17、 1 2 3 4 5 6 7 7.1 7.2 8 8.1 CONTENTS Scope Normative References Definitions Abbreviations . Conventions Overview of Remote Device Control . RDC Infrastructure . Capabilities . 7.1.1 Device List 7.1.2 Stream List 7.1.3 Standard Capability Identifiers Conducted Mode Behaviour . RDC Service Definition

18、 . Device Attributes 8.1.1 RDC-Device-Attributes . 8.2 Device Control . 8.2.1 RDC-Device-Lock 8.2.2 RDC-Device-Lock-Inquire 8.2.3 RDC-Device-Lock-Terminated . 8.2.4 RDC-Device-Control 8.3 Source Selection . 8.3.1 RDC-Source-Select . 8.3.2 RDC-Request-Source-Events 8.3.3 RDC-Source-Change-Event 8.4 D

19、evice Status 8.4.1 RDC-Device-Status . 8.5 Device Events . 8.5.1 RDC-Configure-Device-Events 8.5.2 RDC-Noti-Device-Event 9 9.1 Remote Device Control 9.1.1 Requesting Device Attributes . 9.1.2 . Locking Devices 9.1.3 Device Lock Inquire RDC Service Management Protocol Definition . Page 1 1 2 2 2 3 6

20、6 6 7 8 9 9 10 12 12 13 14 15 15 16 . 16 17 18 18 18 19 20 . Recommendation H.282 (05/99) 111 . . . 9.2 9.3 9.4 10 9.1.4 Device Lock Terminated Indication 9.1.5 Device Control Request Remote Device Source Selection . 9.2.1 Source Selection 9.2.2 Requesting Source Changes 9.2.3 Source Change Events .

21、 Remote Device Status 9.3.1 Device Status Inquire Remote Device Events . 9.4.1 Configuring Device Events . 9.4.2 Notify Device Event RDC PDU Definitions Annex A . Standard Device Classes and Device Control Specifications . A.l Standard Device Classes A . 1. 1 Device Identifier A . 1.2 Device Attribu

22、tes A.1.3 Camera Device Class A.1.4 Slide Presenter Device Class . A.1.5 Microphone Device Class . A.1.6 Light Source Device Class A.1.7 A.1.8 Source Combiner Device Class . Stream Player Recorder Device Class . A.2 Device Control Attributes A.2.1 Camera Control Attributes A.2.2 Camera Control Attri

23、butes Used For Start Stop Movement . A.2.3 A.2.4 Camera Control Attributes Using Spatial Positioning A.2.5 Camera Control Attributes Using the Current Field of View . A.2.6 A.2.7 Stream Player Recorder Control Attributes for Stream Positioning . A.2.8 A.2.9 Stream Player Recorder Attributes for Play

24、back . A.2.1 O Stream Player Recorder Control Attributes for Recording . A.2.11 Source Combiner Control Attributes A.3 Device Event Attributes . A.3.1 Camera Event Attributes . A.3.2 . Slide Presenter Event Attributes . A.3.3 Stream Player Recorder Event Attributes . Camera Control Attributes Using

25、Fixed Range Positioning . Slide Presenter Control Attributes Stream Player Recorder Attributes for Configuration . iv Recommendation H.282 (05/99) Page 21 21 21 21 22 23 23 23 24 24 25 25 44 44 44 45 46 47 47 47 48 49 49 50 54 56 56 57 59 59 61 62 63 63 65 66 66 67 STDmITU-T RECMN H-282-ENGL 1999 48

26、b2591 Ob65711 3Lb D Recommendation H.282 REMOTE DEVICE CONTROL PROTOCOL FOR MULTIMEDIA APPLICATIONS (Geneva, 1999) 1 Scope This Recommendation defines a set of services and a protocol which may be used to perform remote device control in a multimedia conference. Recommendation T.136 describes how to

27、 utilize H.282 using T.120 as the lower layer protocol. Recommendation H.283 describes its application using the RDC logical channel transport established using H.245. Future Recommendations may describe how to utilize H.282 using other lower layer protocols. I I H.282 Common RDC layer protocol I Tl

28、W5520-99 Figure 1m.282 2 Normative 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

29、references are subject to revision; all 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. - ITU

30、-T Recommendation H.281 (1994), A far end camera control protocol for video conferences using H.224. ITU-T Recommendation T. 120 (1 996), Data protocolsfor multimedia conferencing. ITU-T Recommendation T.136 (1999), Remote device control application protocol. ITU-T Recommendation X.680 (1 997), Info

31、rmation technology - Abstract Syntax Notation One (ASN. 1): Specification of basic notation. ITU-T.Recommendation X.691 (1997), Information technology - ASN. I encoding rules - Specijcation of Packed Encoding Rules (PER). - - - - Recommendation H.282 (05/99) 1 - STD-ITU-T RECMN H.282-ENGL 1999 48625

32、93 0665932 252 - ISO/IEC 10646-1 (1 993), Information technology - Universal Multiple-Octet Coded Character Set (UCS) - Part 1 : Architecture and Basic Multilingual Plane. 3 Definitions This Recommendation defines the following terms: 3.1 Node ID: A unique identifier that allows a node to be disting

33、uished from other nodes in the conference. 3.2 RDC Service Provider: An entity that implements the services described in this Recommendation. 3.3 User Application: An entity that makes use of the services offered by the RDC Service Provider in order to perform remote device control. 3.4 Controllable

34、 Device: A device that has the capability to be controlled remotely in a conference environment. 3.5 Device: An entity which provides a specific function, or set of functions, to the conference. Some devices such as cameras and microphones are capable of generating a source to the conference. 3.6 No

35、de: A distinct entity that is participating in a point-to-point or multipoint conference. 3.7 Source: The origin of a real time media stream. 3.8 Lower Layer Protocol: A protocol that is used to transport the RDC PDUs. 3.9 Low Latency Data Channel: A data channel that allows a PDU to be sent with lo

36、w latency. This may be achieved by sending the PDU as unreliable data which means its delivery cannot be guaranteed. 3.10 Unicode: Text string format with Multilingual capabilities as defined in ISO/IEC 10646-1. 4 Abbreviations This Recommendation uses the following abbreviations: PDU Protocol Data

37、Unit RDC Remote Device Control 5 Conventions The primitive parameters of the abstract services defined in this Recommendation use the following key: M: parameter is mandatory; C: parameter is conditional; O: parameter is optional; Blank: parameter is absent. (=): value of the parameter is identical

38、to the value of the corresponding parameter of the preceding primitive, where preceding is defined relative to the order: request, indication, response, confirm. (=RQ): value of the parameter is identical to the value of the corresponding parameter in a preceding primitive, where RQ = request, IN =

39、indication, RS = response, and CF = confirm. 2 Recommendation H.282 (05/99) Primitives are categorized in up to four types: Request, Indication, Response, and Confirm. Some primitives support all of these types, while others do not. These four types are defined as follows: Request primitive: Those t

40、hat are sourced from a User Application to initiate a certain action. Indication primitive: Those that are sourced from an RDC Service Provider either as a result of a Request primitive, or as a result of an RDC Service Provider initiated action. Response primitive: Those that are sourced from a Use

41、r Application in response to an Indication primitive which is defined to require a response. Confirmprimitive: Those that are sourced from an RDC Service Provider as a result of a Response primitive. 6 RDC provides modelling and classification of devices for the purpose of allowing remote activation

42、 and control within a conference environment. A number of standard device classes and a library of standard device attributes are defined by this Recommendation (see Annex A). These aim to address mandatory or commonly required functionality for use in support of multipoint multimedia communication

43、and in particular conferencing . A device is normally a physical entity but may also be a software process and will typically reside at a Terminal node. In both cases the RDC control model requires that the host node is the default owner of a given device and has responsibility for servicing remote

44、device requests. It is not necessary for a host node to be co-located with the device it is hosting. A device can be a source or video cassette recorder. Remote device control provides the following facilities to the conference: - declaration of devices and their associated attributes to enable a co

45、nference participant to determine a profile of a device attached to a remote node; a mechanism to allow a participant to request exclusive access to a remote device in order to perform device control or configuration; mechanisms to allow a participant to control, configure, receive event notificatio

46、n and obtain the status of a remote device; the definition of a standard device class which allows a participant to select a set of remote devices which have their outputs combined together to form a single output stream. Overview of Remote Device Control I receiver of a real time stream or a device

47、 may be both a source and a receiver such as in the case of a - - - 7 RDC Infrastructure 7.1 Capabilities At each node, each device is assigned a device class identifier, according to the type of device, and a unique numeric identifier to distinguish it from other devices with the same class identif

48、ier. The device class and identifier taken together with the unique node ID of the node that owns the device provides a unique handle for each device within the conference. 7.1.1 Device List A node may advertise a device that it will allow to be remotely accessed and controlled via a device profile.

49、 A device list is made up of the device profiles of the same device class. Hence a device list is constructed for each device class that is supported by the node. Each device list is provided to the Recommendation H.282 (05/99) 3 lower layer protocol which it distributes unchanged to all other nodes in the conference using its capability exchange mechanism. A standard capability ID is used to identie the device class of the devices profiles contained in the list (see 7.1.3). A non-standard capability ID may be used to identifi a list of non-standard devices. A