ISSN : 1796-2048
Volume : 3    Issue : 5    Date : December 2008

Logical Mapping: An Intermedia Synchronization Model for Multimedia Distributed Systems
Saul E. Pomares Hernandez, Luis A. Morales Rosales, Jorge Estudillo Ramirez, and Gustavo
Rodriguez Gomez
Page(s): 33-41
Full Text:
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The preservation of temporal dependencies among different media data, such as text, still images,
video and audio, and which have simultaneous distributed sources as origin, is an open research
area and an important issue for emerging distributed multimedia systems, such as Teleimmersion,
Telemedicine, and IPTV. Although there are several works oriented to satisfy temporal
dependencies in distributed multimedia systems, they are far from resolving the problem. In this
paper we propose a logical synchronization model able to specify at runtime any kind of temporal
relationship among the distributed multimedia data involved in a temporal scenario. The
synchronization model is based on a new concept that we call logical mapping. A logical mapping,
in general terms, translates a temporal relation based on a timeline to be expressed according to
its causal dependencies. The logical mappings allow us to avoid the use of global references, such
as a wall clock and shared memory. We note that the proposed intermedia synchronization model
does not require previous knowledge of when, nor of how long, the media involved of a temporal
scenario is executed. Finally, in order to show the viability of the proposed model, a syncrhonization
approach is presented.

Index Terms
distributed systems, temporal synchronization, causal ordering, group communication.