Question 4/XV - Harmonization of audiovisual systems (New Question) Considering (1) that audiovisual services are to be offered in which different combinations of facilities (speech, pictures, Telematics, etc.) may be used during a connection; (2) that such services include videoconferencing, audiographic and Telematic teleconferencing and videophone as studied in other Questions; (3) that other related services may be defined in the future for special applications; (4) that such services should be offered for the simultaneous interconnection of two, three or more terminals in different locations as necessary; (5) that frequently interconnection may be between terminals which are not identical in the facilities which they have available and that in general intending callers will not be aware of the capabilities of the distant terminal; (6) that, in the case of three or more terminals, one or more multipoint control units (MCU) will be required within the network to distribute appropriately the signals representing the various facilities; (7) that, under some circumstances, connections will be required between terminals on networks operating at different bit rates; in particular, services such as videophone and videoconferencing may be offered both on broadband and narrow-band networks requiring gateways between these for interconnection; (8) that in addition to the facilities perceived by the user other signals will be required for the proper organization and control of the system, especially in a multipoint environment; (9) that Recommendation H.200 sets out a framework for Recommendations covering the defined services and the necessary technical conditions for implementing them in a harmonized and interworkable way (see Annexes 1 to 5), 1. What basic signal structure should be recommended for utilization on interconnections of various bit rates corresponding to the bearer services defined in Recommendation....? 2. What modifications should be made to Recommendation H.221, in particular to take into account synchronization aspects when several independent B channels are used? 3. How should recommended coding methods for audio and still or moving television images and Telematic facilities be incorporated into the basic signal structures such that optimal interworking conditions are secured? 4. What equipments and procedures should be recommended to establish correct interworking between similar and dissimilar terminals taking into account the facilities available at each? 5. What harmonized set of control and indication should be recommended to be available within the technical implementation to facilitate correct operation and provide information required by user-friendly terminals? 6. What should be recommended for the specification of multipoint control units for the various types of interconnection and for the procedures required for establishing multipoint calls on digital networks? 7. What should be recommended for the specification that should be applied to equipment required at gateways between different networks and/or interconnection bit rates? Notes 1.The study of this Question should be coordinated with: 1.1 Study Group I for service definition, 1.2 Study Group II for network operation issue, 1.3 Study Group VIII for Telematic issues, 1.4 Study Group XVIII for ISDN issues. 2. The study of this Question should be coordinated with the study of Question 21/XV. ANNEX 1 (to Question 4/XV) Enhanced draft Recommendation H.200 FRAMEWORK FOR RECOMMENDATIONS FOR AUDIOVISUAL SERVICES I. Service definition CCITT Rec. No. AV.100 General Recommendation for AV services F.700 AV.110 Teleconference services F.700, F.710 AV.111 Audiographic conference service AV.112 Videoconference service AV.120 Videophone services AV.121 Basic narrow-band videophone service in the ISDN F... AV.130 ... (Other AV Services) II. Infrastructure AV.200 General Recommendation for AV service infrastructure AV.210 Reference network configuration AV.220 General Recommendation for frame structures AV.221 Frame structure for a 64 kbit/s channel in audiovisual teleservices H.221 AV.222 Frame structure for 384 - 2048 kbit/s channels audiovisual teleservices H.222 AV.223 ... (Frame structures for higher bit-rates) AV.230 General Recommendation for AV system control and indications AV.231 Multipoint control unit for 64 kbit/s AV AV.232 Multipoint control for 384 - 2048 kbit/s AV.233 AV.240 Principles for communication between AV terminals AV.241 System aspects for the use of the 7 kHz audio codec within 64 kbit/s G.72Y AV.242 System for establishing communication between AV terminals using one or two 64 kbit/s channels AV.250 Audio coding AV.251 Narrow-band audio coding at 64 kbit/s G.711 AV.252 Wideband audio coding in 64 kbit/s G.722 AV.253 Audio coding at 40/32 kbit/s (using G.721/728 or extending G.722 down) AV.254 Narrow-band speech coding at 16 kbit/s AV.260 Video coding AV.261 AV.262 n x 384 kbit/s video codec H.261 AV.263 m x 64 kbit/s video codec H.12xy III. Systems and terminal equipment AV.300 General Recommendations for AV systems and terminals AV.310 (Requirements for teleconferencing) AV.311 Audiographic system and terminal requirements AV.312 Videoconference system and terminal requirements AV.313 Teleconference protocol AV.320 Requirements for videophone services IV. Network aspects AV.400 AV.410 Reservation systems AV.420 MLC for use in audiovisual calls AV.430 Call control C&I AV.440 Multipoint call set-up Note 1 - It is intended to merge the substance of existing Recommendations H.100, 110 into this framework in the next study period. Note 2 - Entries in parentheses are indicative of the purpose of the various positions in the framework. Appendix (to Recommendation H.200) Present status and contents of proposed Recommendations in H.200 I. Service definitions AV.100 General Recommendation for audiovisual services (SG I, MM, 1988) List of specific services included in the general set. List of facilities (or "media") included in the general set. Call-control requirements, including multipoint. Interworking between various AV services. AV.110 Teleconference services (SG I, MM, 1988) Draft Recommendation F.700 (COM I-R 23 Part III.7) AV.111 Audiographic conference service (SG I/II, MM, 1992) Description of service; basic facilities. Optional facilities. Terminal configuration and accommodation. Control and indications. Perceived performance on international calls. Network accesses applicable to the service. Availability and conditions of international service. Supplementary services (cass forwarding/transfer, interconnection to other types of audiovisual service terminal). Use of Telematic facilities. Quality description for audio, taking into account transducer and room performance, options as to the particular coding used from the infrastructure set, and the effect of transmission errors. AV.112 Videoconference service (SG I/II, MM, 1989) As for AV.111 above with the following additions: Video system (see also AV.100, AV.110 and AV.313). Terminal configuration and accommodation includes video aspects. Quality description for video including effect of terminal transducers and room conditions, video coding options from the infrastructure set, and the effect of transmission errors (the description must take into account the fact that video coding may be changed within the network, for example from high bit rate to low bit rate coding). AV.120 Videophone service (SG I/II, MM, 1992) As for the videoconference service AV.112 above, though of course the details will differ in many respects, see also AV.320. AV.121 Basic narrow-band videophone service in the ISDN (SG I, MM, 1988) Draft Recommendation F... (COM I-R 22 Part IV.3). AV.130 Other audiovisual services Such Recommendations should cover audiovisual services not already covered by teleconferencing or videophone. Known applications are telemedicine and remote lecturing. II. Infrastructure Recommendations AV.200General Recommendation for audiovisual service infrastructure (SG XV, NDK, 1992) Outline proposed in COM XV-R 26 (Annex 1 to Part B.5). AV.210 Reference network configuration of AV services (SG XV, NDK, 1992) Description/explanation. Definitions. Reference configuration. Interfaces. Functional specification for multipoint working (refer to AV.230). Interconnections between "broadband" and lower bit rate networks. Interregional interconnections. AV.220 General Recommendations for frame structure (SG XV, NDK, 1992) Short umbrella Recommendation for the AV.220 series AV.221Frame structure for 64 kbit/s channel in audiovisual teleservices (SG XV, NDK, 1988) Draft Recommendation H.221 (COM XV-R 26 Part C.7, April 1988) AV.222Frame structures for 384 - 2048 kbit/s channels in AV teleservices (SG XV, NDK, 1988) Utilization of Recommendation H.221 with additional 64 kbit/s channels for video, etc. Utilization of frame structures for 1544 and 2048 kbit/s to Recommendation G.704. AV.230General Recommendation for AV system control and indications (SG XV, NDK, 1992) Outline proposed in COM XV-R 26 (Annex 1 to Part B.5). AV.231 Multipoint control of 64 kbit/s AV services (SG VIII, LD, 1992) Implementation of AV.230 in the case of calls using single 64 kbit/s paths only. Ditto, using two 64 kbit/s paths. Ditto, using ISDN to Recommendation I-Series. AV.232 Multipoint control of 384 - 2048 kbit/s services (SG XV, NDK, 1992) Implementation of AV.230 in the case of 384 kbit/s paths. Ditto, using 1544 and 2048 kbit/s paths. AV.240 Principles for communication between AV terminals (SG XV, NDK, 1989) Text proposed in COM XV-R 26 (Annex 2 to Part B.5). AV.241System aspects for the use of the 7 kHz audio codec within 64 kbit/s (SG XVIII, XM, 1988) Draft Recommendation G.72Y. AV.242System for establishing communication between AV terminals using one or two 64 kbit/s channels (SG XV, NDK, 1989) Preliminary text proposed in COM XV-R 26 (Annex 6 to Part B.5). AV.250 Audio coding AV.251 Narrow-band audio coding at 64 kbit/s G.711 AV.252 Wideband audio coding in 64 kbit/s G.722 AV.253 Audio coding at 40/32 kbit/s (SG XV, XX, 1989) (Using G.721/728 or extending G.722 down, or extending AV.254 up.) AV.254 Narrow-band speech coding at 16 kbit/s (SG XV, XX, 1989) AV.260 Video coding AV.261 AV.262 n x 384 kbit/s video codec (SG XV, SO, 1989) H.12X AV.263 m x 64 kbit/s video codec (SG XV, SO, 1989) H.12Y III. Systems and terminal equipment AV.300 General Recommendation for AV systems and terminals AV.301 General Recommendations on AV terminal equipment AV.313 Teleconference protocol (SG VIII, LD, 1992) AV.310 Requirements for teleconferencing (SG VIII, LD, 1992) AV.311 Audiographic system and terminal requirements (SG VIII, LD, 1992) Transducers. Room disposition (mainly left to customer choice). Processing (mixing, echo cancellation, voice switching, etc.). Noise specification. Audio alignment (level-setting). Subjective quality (in association with infrastructure coding options as given in AV.250 Series). AV.312 Videoconference system and terminal requirements (SG XV, SO, 1992) Transducers. Room disposition and lighting. Noise specification. Processing (mixing/split-screen, switching, etc.). Video alignment. Subjective quality (including video coding options according to AV.260 Series). AV.320 Requirements for videophone service (SG XV, SO, 1992) Generally as for videoconference, AV.312 above (differences of detail). IV. Network aspects AV.400 Multipoint call set-up (SG XVIII, XX, 1992) Purely from the network point of view, and nothing specifically to do with audiovisual services, there will be a need to ensure that multipoint calls can be set up in a suitable way from the human factor point of view. Clearly this must be closely coordinated with the requirements of teleconferencing, and of conference calls as a supplementary service to videophone and other audiovisual services (see AV.230). Charging aspects must also be taken into account. AV.410 Reservation systems (SG XVIII, XX, 1992) Rapporteurs (at April 1988) MM: MATSUMOTO Mitsuji NDK: KENYON Norman LD: DIJKSTRA Lokke XM: MAITRE Xavier SO: OKUBO Sakae XX: to be appointed ANNEX 2 (to Question 4/XV) Draft outline for Recommendation H.200/AV.200 GENERAL RECOMMENDATION FOR INFRASTRUCTURE FOR AUDIOVISUAL TELESERVICES 1. Introduction recoup ANNEX 3 (to Question 4/XV) Draft Recommendation H.200/AV.230 OUTLINE GENERAL RECOMMENDATION FOR AUDIOVISUAL SYSTEM CONTROL AND INDICATIONS Contents 1. INTRODUCTION 1. Introduction recoup 4.1 Control (C) 4.2 Indication (I) ANNEX 4 (to Question 4/XV) Draft Recommendation H.200/AV.240 PRINCIPLES FOR COMMUNICATION BETWEEN AUDIOVISUAL TERMINALS Contents 1. INTRODUCTION 5. recoup The recoup 3.2 recoup 4.2.3 recoup 5. recoup (c) recoup figure figure table ANNEX 5 (to Question 4/XV) Draft Recommendation H.200/AV.242 SYSTEM FOR ESTABLISHING COMMUNICATION BETWEEN AUDIOVISUAL TERMINALS USING ONE OR TWO 64 KBIT/S CHANNELS 1. Introduction Mode 6: recoup 2.3 + - + Type of remote terminal + 0 1 2 3 3V/1 3V/2 + + + - Type of Type 1 local MODE 1 terminal Type 2 + MODE 2 Type 3 + MODE 7 Type 3V1 + MODE 7V1 Type 3V2 + MODE 7V2 + - + FIGURE 1/AV.242 Mode of operation upon completion of the initialization procedure A second recoup 4.3 Frame recovery sequence C recoup Addition of a recoup When the terminal is receiving recoup 7. Network recoup