BIB-VERSION:: CS-TR-v2.0 ID:: ncstrl.dartmouthcs//TR2004-514 ENTRY:: August 05, 2004 ORGANIZATION:: Dartmouth College, Computer Science TITLE:: Solar: Building A Context Fusion Network for Pervasive Computing TYPE:: Technical Report (paper) REVISION:: 1 AUTHOR:: Chen, Guanling DATE:: August 2004 RETRIEVAL:: For a paper copy, email 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:: PDF at http://www.cs.dartmouth.edu/reports/TR2004-514.pdf ABSTRACT:: The complexity of developing context-aware pervasive-computing applications calls for distributed software infrastructures that assist applications to collect, aggregate, and disseminate contextual data. In this dissertation, we present a Context Fusion Network (CFN), called Solar, which is built with a scalable and self-organized service overlay. Solar is flexible and allows applications to select distributed data sources and compose them with customized data-fusion operators into a directed acyclic information flow graph. Such a graph represents how an application computes high-level understandings of its execution context from low-level sensory data. To manage application-specified operators on a set of overlay nodes called Planets, Solar provides several unique services such as application-level multicast with policy-driven data reduction to handle buffer overflow, context-sensitive resource discovery to handle environment dynamics, and proactive monitoring and recovery to handle common failures. Experimental results show that these services perform well on a typical DHT-based peer-to-peer routing substrate. In this dissertation, we also discuss experience, insights, and lessons learned from our quantitative analysis of the input sensors, a detailed case study of a Solar application, and development of other applications in different domains. NOTE:: This is a reformatted version of Guanling Chen's Ph.D. dissertation. Unlike the dissertation submitted to Dartmouth College, this version is single-spaced, uses 11pt fonts, and is formatted specifically for double-sided printing. END:: ncstrl.dartmouthcs//TR2004-514