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.
Multicasting will be a new experience for many meeting participants.
The goal of the multicasting is to increase participation in the meeting as widely
as possible without impinging negatively on the experience of local attendees.
If your session is listed among those which will be broadcast,
please be aware of the following:
Given the low quality of MBONE video, ask yourself "how would this presentation work on
radio"? If you base your presentation on clear explanatory language, it is likely to be more
successful, even for local participants.
- 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.
- 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
- 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.
- 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.
- 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!
Guided Tour of this site
Mail to the MBONE team
Created: 22 March 1996
Last updated: 26 March 1996