BIB-VERSION:: CS-TR-v2.0
ID:: ncstrl.dartmouthcs//TR2002-421
ENTRY:: February 28, 2002
ORGANIZATION:: Dartmouth College, Computer Science
TITLE:: Solar: A pervasive-computing infrastructure for context-aware mobile applications
TYPE:: Technical Report (paper)
REVISION:: 1
AUTHOR:: Chen, Guanling
AUTHOR:: Kotz, David
DATE:: February 2002
RETRIEVAL:: For a paper copy, email <reports@cs.dartmouth.edu>
RETRIEVAL:: For a paper copy, write to
       Technical Report Librarian
       Department of Computer Science
       Dartmouth College
       6211 Sudikoff Laboratory
       Hanover, NH 03755-3510
       USA
RETRIEVAL:: Compressed Postscript at http://www.cs.dartmouth.edu/reports/TR2002-421.ps.Z
RETRIEVAL:: PDF at http://www.cs.dartmouth.edu/reports/TR2002-421.pdf
ABSTRACT:: 
Emerging pervasive computing technologies transform the way we live
and work by embedding computation in our surrounding environment.  To
avoid increasing complexity, and allow the user to concentrate on her
tasks, applications must automatically adapt to their changing
\emph{context}, the physical and computational environment in which
they run.  To support these ``context-aware'' applications we propose
a graph-based abstraction for collecting, aggregating, and
disseminating context information.  The abstraction models context
information as \emph{events}, which are produced by \emph{sources},
flow through a directed acyclic graph of event-processing
\emph{operators}, and are delivered to subscribing applications.
Applications describe their desired event stream as a tree of
operators that aggregate low-level context information published by
existing sources into the high-level context information needed by the
application.  The \emph{operator graph\/} is thus the dynamic
combination of all applications' subscription trees.  In this paper,
we motivate our graph abstraction by discussing several applications
under development, sketch the architecture of our system (``Solar'')
that implements our abstraction, report some early experimental
results from the prototype, and outline issues for future research.
END:: ncstrl.dartmouthcs//TR2002-421