Fifth International World Wide Web Conference

May 6-10, 1996, Paris, France

Notes to Presenters of Multicast Sessions

In addition to the general preparation giude, the following guide gives you some special considerations in the preparation of your presentation for those sessions which will be broadcast on the MBONE.

If your session is listed among those which will be broadcast, please be aware of the following:

• The session you are participating in will be transmitted live over the Internet via a technology known as MBONE (Multicasting backBONE). This will allow many people all over the world to view and hear your presentation, and to participate during question periods. The MBONE program which will be broadcast comes from these sources:
  • cameras in the conference room that can be trained on you
  • directly from your presentation (via direct computer video out or by filming the screen in the front of the room).
  • audio from microphones in the conference room

• MBONE audio quality is equivalent to a good telephone connection. It is the single most important information source for remote attendees. It is important to speak slowly and clearly, and to explain what you are doing during demonstrations.

• MBONE video is slow (2-8 frames per second). The algorithms involved try to repaint only those parts of the screen that are changing. When a scene changes drastically, it can take considerable time, on the order of 30 seconds (depending upon network conditions) to repaint the image. In past multicast events, this has proven to be particularly troublesome when trying to pick up traditional slides or overheads from a projection screen via a TV camera. First, images with small type and handwriting are often illegible. Second, the screen is sometimes not repainted completely when the presenter moves on to the next slide/overhead, so the remote attendee can not read the material. Nervous presenters often wiggle an overhead as they talk, making it impossible to view remotely. MBONE video consumes most the the program bandwith, but generally conveys less information than good audio. MBONE video is UDP-based, so there is no error correction, and "drop-outs" occur on occasion.

1. The session chairperson will help coordinate activities with the operator running the multicasting workstation, and another person known as a interlocutor, who acts as a stand-in for remote participants who wish to ask questions. The chairperson may also gently remind you to slow down if you are speaking too quickly or making excessively rapid movements.

2. Remote viewers are technically capable of recording part or all of your presentation. If you do not wish such recordings to be made, please so inform the chairperson prior to the start of the session, and the chairperson will make an appropriate request to remote viewers when introducing you.

3. PLEASE PREPARE YOUR MATERIALS CAREFULLY IN ADVANCE, following these guidelines, and practice using them, to ensure a smooth presentation that fits within your time allotment.

4. If you intend to demonstrate audio or full-motion video, warn the session chairperson and multicasting team in advance, so that they can make appropriate preparations to multicast these parts of your presentation.

If you have any questions or concerns regarding the MBONE broadcasts, please contact www5-info as soon as possible. Thanks and GOOD LUCK!

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