Source codeCoda cartoons
places many demands on a system. Size and weight constraints limit the
computing resources on a mobile client. Network connectivity is highly
variable, and sometimes non-existent. Battery life is a nagging concern.
In spite of these challenges, mobile users need to access and update
information at any time and from any place.
Coda and Odyssey are experimental
systems built by the research group of Professor
M. Satyanarayanan in the School of
Computer Science at Carnegie Mellon University
to explore these issues. Both systems embody adaptation
at many levels. Coda implements application-transparent
the context of a distributed file system. Since
the Posix interface is preserved, legacy applications can run unmodified
on Coda. In contrast, Odyssey supports a type of adaptation called
that is better suited to multimedia data such as speech and video.
This overview paper provides more details
on these concepts.