A multimedia presentation is a presentation of
information in multimedia format. Such a presentation
may contain more than one multimedia objec t, such as
audio, video, image, text. We are interested in
time-based multimedia presentations, in which each
media object is associated with a start time and a
playback duration. Temporal and spatial
synchronizations are usually required among media
objects. In a distributed environment, the
intermediate nodes along the transmission route. A
very important requirement for a time-based multimedia
presentation is to assure the playback smoothness.
This mean that the transmission of the media objects
must be conducted in such a way that each object is in
the buffer space of the client's workstation before
its start time. Previous work, such as XOCPN, only
concentrated on the scheduling of object delivery. We
propose our approach for a networking environment
where quality of service can be specified. Instead of
downloading all the media objects to a client's
workstation before a presentation can start, we divide
all the participatiing media objects into several
synchronzation-working groups and have playback and
transmission proceeding in parallel. We propose the
idea of start time delay, which is the amount of time
that the client must wait after receiving the first
bit of data before a presentation can commence. We
will show that the start time delay can guarantee
smooth playback of a presentation, even when the media
object size exceeds the reserved bandwidth
temporarily. We also propose a new storage
architecture which stores the media objects based on
the notion of synchronization-working group instead of
media object type. The download time can be shortened
and the client can get a faster response.