1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU H.310 (09/98) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Infrastructure of audiovisual services - Systems and terminal equipment for audiovisual services Broad band audiovisual communication systems and ter
2、minals ITU-T Recommendation H.31 O (Previously CCITT Recommendation) STD-ITU-T RECMN H.3LO-ENGL 1998 D 48b259L Ob543b0 724 ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS Characteristics of transmission channels used for other than telephone purposes Use of telephone-type circuits
3、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 H. 1 O-H. I9 H.20-H.29 H.30-H.39 H.40-H.49 Characteristics of data signals CHARACTERISTICS OF VISUAL TELEPHO
4、NE SYSTEMS INFRASTRUCTURE OF AUDIOVISUAL SERVICES General Transmission multiplexing and synchronization Systems aspects Communication procedures Coding of moving video H.50-H.99 H.1 OO-H. 199 H.200-H.219 H.220-H.229 H.230-H.239 H.24-H.259 H .26 all users of this Recommendation are therefore encourag
5、ed 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. CCITT Recommendation G.711 (1988), Pulse Code Modulation (PCM) of voice j-equencies. CCITT Recom
6、mendation G.722 (1988), 7 kHz audio-coding within 64 kbith. ITU-T Recommendation G.723.1 (1 996), Speech codecs: Dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3 kbith. CCITT Recommendation G.728 (1 992), Coding of speech at 16 kbith using low-delay code excited linea
7、r prediction. ITU-T Recommendation G.729 (1996), Coding of speech at 8 kbith using Conjugate Structure Algebraic-Code-Excited Linear-Prediction (CS-ACELP). Annex A to G.729 (1996), Reduced complexity 8 kbith CS-ACELP speech codec. CCITT Recommendation H. 100 (1 988), Visual telephone systems. ITU-T
8、Recommendation H.221 (1997), Frame structure for a 64 to 1920 kbit/s channel in audiovisual telesewices. ITU-T Recommendation H.222.0 (1 995) I ISOIEC 138 18-1 : 1996, Information technology - Generic coding of moving pictures and associated audio information: Systems. ITU-T Recommendation H.222.1 (
9、1 996), Multimedia multiplex and synchronization for audiovisual communication in ATM environments. ITU-T Recommendation H.224 (1 994), A real time control protocol for simplex applications using the H.22 I LSD/HSD/MLP channels. ITU-T Recommendation H.230 (1997), Frame-synchronous control and indica
10、tion signals for audiovisual systems. ITU-T Recommendation H.233 (1 999, Confidentiality system for audiovisual services. ITU-T Recommendation H.234 (1 994), Encryption key management and authentication system for audiovisual services. ITU-T Recommendation H.242 (1 997), System for establishing comm
11、unication between audiovisual terminals using digital channels up to 2 Mbith. ITU-T Recommendation H.245 (1 998), Control protocol for multimedia communication. ITU-T Recommendation H.261 (1993), Video codec for audiovisual services at p x 64 kbith. ITU-T Recommendation H.262 (1 995) I ISO/IEC 13 8
12、18-2: 1995, Information technology - Generic coding of moving pictures and associated audio information: Video. ITU-T Recommendation H.263 (1998), Video coding for low bit rate communication. ITU-T Recommendation H.281 (1994), A far end camera control protocol for videoconferences using H. 224. Reco
13、mmendation H.310 (09/98) 3 ITU-T Recommendation H.320 (1 997), Narrow-band visual telephone systems and terminal equipment. ITU-T Recommendation H.321 (1998), Adaptation of H.320 visual telephone terminals to B-ISDN environments. ITU-T Recommendation 1.3 1 1 (1996), B-ISDN general network aspects. I
14、TU-T Recommendation 1.361 (1 999, B-ISDN ATM layer specification. ITU-T Recommendation 1,363.1 (1 996), B-ISDN ATM adaptation layer specification: Type 1 AAL. ITU-T Recommendation 1.363.5 (1 996), B-ISDN ATM adaptation layer specijkation: Type 5 AAL. CCITT Recommendation 4.922 (1 992), ISDN data lin
15、k layer specification for pame mode bearer services. ITU-T Recommendation 4.201 O (1 999, Broadband integrated services digital network overview - Signalling capability set 1, release I. ITU-T Recommendation 4.21 10 (1994), B-ISDN ATM adaptation layer - Service Specific Connection Oriented Protocol
16、(SSCOP) . ITU-T Recommendation 4.21 30 (1 994), B-ISDN signalling ATM adaptation layer - Service specijic coordination function for support of signalling at the user-network interface (SSCF at UNQ. ITU-T Recommendation 4.293 1 (1 999, Digital subscriber Signalling System No. 2 - User- Network Interf
17、ace (UNQ layer 3 specification for basic call/connection control. ITU-T Recommendation 4.2941.1 (1 997), Digital subscriber Signalling System No. 2: Generic identlJiers transport. ITU-T Recommendation 4.2961.1 (1 999, Digital subscriber Signalling System No. 2 (DSS 2) - Additional trafic parameters:
18、 Additional signalling capabilities to support traflc parameters for the tagging option and the sustainable cell rate parameter set. ITU-T Recommendation 4.2961.2 (1997), Digital subscriber Signalling System No. 2 - Additional trafic parameters: Support of ATM transfer capability in the broadband be
19、arer capability information element. ITU-T Recommendation 4.2971 (1995), Digital subscriber Signalling System No. 2 - User- network interface layer 3 specijication for point-to-multipoint calUconnection control. ITU-T Recommendation T.84 (1996) I ISOAEC 1091 8-3: 1996, Information technology - Digit
20、al compression and coding of continuous-tone still images: Extensions. ITU-T Recommendation T. 120 (1 996), Data protocols for multimedia conferencing. ITU-T Recommendation T. 123 (1 996), Network specific data protocol stach for multimedia conferencing. ITU-T Recommendation T.434 (1 996), Binary fi
21、le transfer format for the telematic services. ITU-T Recommendation X.214 (1995) I ISOIEC 8072: 1996, Information technology - Open Systems Interconnection - Transport service definition. ITU-T Recommendation X.224 (1995) I ISOIEC 8073 : 1997, Information technology - Open Systems Interconnection -
22、Protocol for providing the connection-mode transport service. Recommendation H.310 (09198) 42 43 44 45 46 ITU-T Recommendation X.680 (1 997) I ISOAEC 8824-1 : 1998, Information technology - Abstract Syntax Notation One (ASN. I): SpeciJcation of basic notation. ITU-T Recommendation X.691 (1997) I ISO
23、/IEC 8825-2: 1998, Information technology - ASN I encoding rules - Specijkation of Packed Encoding Rules (PER). ISOAEC 1 1 172-3 : 1993, Information technology - Coding of moving pictures and associated audio for digital storage media at up to about 1.5 Mith - Part 3: Audio. ISO/IEC 1381 8-3: 1995,
24、Information technology - Generic coding of moving pictures and associated audio information - Part 3: Audio. ISO/IEC 138 1 8-6: 1998, Information technology - Generic coding of moving pictures and associated audio information - Part 6: Extensions for DSM-CC. 3 Definitions This Recommendation defines
25、 the following terms. 3.1 3.2 associated transmission paths between two terminals, one in each direction of transmission. 3.3 3.4 receive and decode that particular signal. 3.5 3.6 3.7 . control and indication: End-to-end signalling between terminals, consisting of control, which requires action but
26、 no explicit response in the receiver, and indication which contains information but does not require action or response in the receiver. 3.8 3.9 other coded bit stream. 3.10 3.1 1 network environments. 3.12 channel to which they refer. 3.13 or response. 3.14 transmission of information. 3.15 logica
27、l channel. 3.16 open and close logical channels. audiovisual information: Information including audio andor video information. bidirectional logical channel: A bidirectional logical channel consists of a pair of bidirectional terminal A terminal which can send and receive audiovisual information. ca
28、pability: A terminal has a particular capability if it is able to encode and transmit or channel: A channel is a unidirectional link between two end points. command: A command is a message that requires action but no explicit response. customer premises network: An ATM network administered by the us
29、er. elementary stream: Elementary stream is a generic term for a coded video, coded audio or entry: The word entry is used to refer to elements in sets or tables, such as capability sets. gateway: A function that converts transmission formats andor protocols between different in-band: In-band messag
30、es are those that are transported within the channel or logical indication: An indication is a message that contains information but does not require action logical channel: A logical channel is a unidirectional path or bidirectional path for the logical channel number: A logical channel number is a
31、 number that identifies a single logical channel signalling: Logical channel signalling is a set of procedures that are used to Recommendation H.310 (09/98) 5 3.17 master terminal: A master terminal is the terminal that is determined as being the master terminal by the master-slave determination pro
32、cedure used by this Recommendation. 3.18 medium type: A medium type is a single form of information that is presented to a user or the data representing that information: video, audio and text are example medium types. 3.19 mode: A mode is a set of elementary streams that a terminal is transmitting,
33、 intends to transmit, or would like to receive. 3.20 multimedia communication: Multimedia communication refers to the transmission and/or reception of signals of two or more medium types simultaneously. 3.21 multipoint: Multipoint refers to the simultaneous interconnection of three or more terminals
34、 to allow communication among several sites through the use of multipoint control units (bridges) that centrally direct the flow of information.- 3.22 non-standard: Not conforming to a national or international standard referenced in this Recommendation. 3.23 out-of-band: Out-of-band messages are th
35、ose that are not transported within the user-to-user information channel. 3.24 public network: An ATM network administered by the network provider for public access. 3.25 request: A request is a message that results in action by the remote terminal and requires an immediate response from it. 3.26 re
36、sponse: A response is a message that is the response to a request. 3.27 session: A session is a period of communication between two terminals which may be conversational or non-conversational (for example retrieval from a database). 3.28 slave terminal:-A slave terminal is the terminal that is deter
37、mined as being the slave terminal by the master-slave determination procedure used by this Recommendation. 3.29 subchannel: A channel in Recommendation H.222.1 formed from packets having a unique multiplex identifier field value. A subchannel carries one H.222.1 elementary stream. A subchannel is un
38、idirectional. There may be many subchannels within one ATM virtual channel. 3.30 support: The ability to operate in a given mode; however, a requirement to support a mode does not mean that the mode shall actually be used at all times: unless prohibited, other modes may be used by mutual negotiation
39、. 3.31 terminal: A terminal is any endpoint and may be a users terminal or some other communication system such as an MCU or an information server. 3.32 unidirectional logical channel: A unidirectional logical channel is a path for the transmission of a single elementary stream fiom one terminal to
40、another. 3.33 unidirectional terminal: A terminal which can only send or receive audiovisual information. 4 Abbreviations This Recommendation uses the following abbreviations: AAL ATM Adaptation Layer ASN. 1 Abstract Syntax Notation One ATM Asynchronous Transfer Mode B-BC Broadband Bearer Capability
41、 6 Recommendation H.310 (09/98) B-HLI B-ISDN B-LCSE C 11 172, (H.261, H.262) Data Call Management 13818) Note 1 Synchronous Signalling SSCS.uNI FR-sscs (4.2130) (1.365.1) (1.363.5) (1.363.5) (1.363.5) T. 120 7 X.224 Classe O II i I= I II I l I I I I I (1.363.1) (1.363.5) (1.363.1) (1.363.5) CPCS 5 (
42、1.363.5) (1.363.5) I I I I I 1 I I ATM (1.361) T1604890-98 NOTE 1 -T.120 may be carried within the H.222.1 multiplex or in a separate ATM virtual channel, as specified in Recommendation T.123. NOTE 2 -Video frame synchronous signals are described in 6.3.5.3. NOTE 3 - H.222.1H.222.0 functions include
43、 multiplexing, timebase recovery, media synchronization, jitter removal, buffer managemenf security and access control, in-band signalling, and trick modes. Recommendation H.222.1 specifies elements and procedures from the generic H.222.0, for their use in ATM environments, and also specifies code p
44、oints and procedures for ITU-T defined elementary streams. NOTE 4 -AAL type 1 CS functions include transmission clock recovery, jitter removal, bit error correction, cell loss correction, and data structure preservation. NOTE 5 -AAL type 5 (CPCS) functions include bit error detection, cell loss dete
45、ction, and data structure preservation. NOTE 6 -H.221 is required in the H.310 RAST-1, RAST-5 and RAST-1 H.3 1 O ROT-5 and SOT-5 which support AAL 5; 0 H.3 10 ROT-1 e H.3 1 O RAST-1 Network Adaptation; signalling (both user-to-user and user-to-network). -4 communication mode is defined as a combinat
46、ion of certain parameters of the above capabilities. Based on the different capabilities of H.3 1 O terminals, two classes of communication modes are specified: H.320h4.32 1 interoperation modes; native H.3 1 O communication modes. Unidirectional H.3 1 O terminals need only support native H.3 1 O co
47、mmunication modes of operation, that is, unidirectional terminals may optionally support the H.320M.32 1 interoperation modes. At the start of the call, H.310 terminals shall identifi the remote terminal type (H.320M.321, H.310 bidirectional, etc.) via exchange of 4.2931 information elements, and sh
48、all use either H.245 or H.242 to perform capability exchange and other procedures. This Recommendation mandates the support of particular functionalities by the different terminal types. However, this does not imply that a particular communication mode shall be used by that terminal type during a gi
49、ven communication session. For example, RAST terminals shall support H.261 video capabilities for intenvorking with H.320h4.321 terminals, but the use of H.261 in the native mode, that is, when H.222.1 is used, is optional. The following subclauses describe mandatory and optional capabilities. Optional capabilities are included as guidelines for implementations and are in no way intended to be exhaustive lists of what may be implemented. 6.3.1 Video capabilities All H.310 terminals shall support Recommendation H.262 at the Main Profile at Main Level (MPML) conformance poi
