Dear Ms. Li Yan, Mr. Sakae Okubo and other Q.12/16 experts,
Thank you for your contribution for H.bmultipoint.
Updated draft of H.bmultipoint (Version 1.1) is now available on ftp.gctech.co.jp incoming directory.
Filename is "hbmult-v11.doc". The cover page of the file is attached below.
I greatly count on expert's contribution to finalize the draft.
Best regards,
Hideh
Hidenobu Harasaki harasaki@ccm.CL.nec.co.jp Principal Researcher C&C Media Research Labs., NEC Corporation Phone: +81 44 856 8083 Fax: +81 44 856 2232
------------------------------------------------------------------------ This draft is H.bmultipoint version 1.1, which is an updated version of Version 1 presented at Sunriver meeting.
During Sunriver meeting, the following comments or suggestions were raised.
1. Delete "using H.246 gateways" from the second sentence and to describe in Section 9 a couple of possibilities; use of H.246 functions, use of interopration mode, transcoding, etc. It was also suggested to focus on H.320 as a typical case of other H-series terminals.
2. Dynamic VC change (i.e. between a multicast leaf and a point-to-point party when the current speaker switches) may be expensive and suffer noticeable delay. Since VC setup is not designed to guarantee to work in a real-time fashion. it needs some time (It could be 1.5 -20 seconds was mentioned).
3. Include system configuration of H.bmultipoint MCU as in H.231.
4. Include reference to service Recommendations such as F.700, F.710, F.720.
5. Concentrate on multicast by MCU and multicast by the root MCU initiated join.
6. Editor can use existing texts in H.140, H.231/H.243 and other related exiting Recommendations.
7. Tables 1 and 2 for master-slave determination need correction.
8. The next draft of H.bmultipoint will include the following implementation alternatives as information: remultiplexing, transcoding, use of layered coding, and use of H.320/H.321 interoperation mode.
The editor needs expert's assistances to reflect some of the above comments or suggestions, and to fill the blanks in the draft Recommendatation.
* Specific text referring to F.700, F.710 and F.720, and where the text should be inserted.
* Is there any solution to cope with the problem No. 2 above?
* In Section 6, call setup/release scenario is exactly the same as H.310 except point-to-multipoint audiovisual connection setup procedure. How a terminal can join a conference as a multicast leaf using H.245 negotiation? If the terminal is ROT, the MCU can automatically invite it as a multicast leaf. But considering the case of RAST, do we need to add H.245 message? Or, the terminal shall be declare that I'm a ROT?
* Chapter 5 shall be a general system description, while chapter 7 explicitly specifies how the MCU behave. What are the essential specifications in Chapter 7?
Any contributions toward the determination in January 1998 are solicited.
Hidenobu Harasaki (harasaki@ccm.cl.nec.co.jp), editor for H.bmultipoint ------------------------------------------------------------------------