Taxonomy of computer systems research problems in pervasive computing Remote communication Fault tolerance High availability Remote information access Distributed security Mobile networking Mobile information access Adaptive applications Energy-aware systems Location sensitivity Distributed systems Mobile computing Pervasive computing Smart spaces Invisibility Localized scalability Context-awareness Federated communities Virtualization Standardization Uneven condition Grid computing Global Smart Space
Four Additional Research Thrusts Effective Use of Smart Spaces Invisibility Localized Scalability Masking Uneven Conditioning Pervasive Computing ： Vision and Challenges Personal Communications, IEEE, Vol. 8, Issue: 4, Aug. 2001, p.10 - 17
Context-Awareness What is context? Context is any information that can be used to characterize the situation of an entity. An entity is a person, place, or object that is considered relevant to the interaction between a user and an application, including the user and applications themselves. Towards a Better Understanding of Context and Context-Awareness GVU Technical Report GIT-GVU-99-22, College of Computing, Georgia Institute of Technology
Context-Awareness Context-aware applications look at the who ’ s, where ’ s, when ’ s and what ’ s of entities and use this information to determine why the situation is occurring. There are four primary types of context Location Identity Activity Time Towards a Better Understanding of Context and Context-Awareness GVU Technical Report GIT-GVU-99-22, College of Computing, Georgia Institute of Technology
Issues of implementing a context- aware system How is context represented internally? How is this information combined with system and application state? Where is context stored? What are the relevant data structures and algorithms? How frequently does context information have to be consulted? What is the overhead of taking context into account? What techniques can one use to keep this overhead low?
Issues of implementing a context- aware system What are the minimal services an environment needs to provide to make context awareness feasible? What are reasonable fallback positions if an environment does not provide such services? Is historical context useful? What are the relative merits of different location- sensing technologies? Under what circumstances should one be used in preference to another? Should location information be treated just like any other context information, or should it be handled differently?
AHRI Purpose: Design for people Background: Georgia Tech Broadband Institute Residential Laboratory a three-story, 5040-square-foot home that functions a living laboratory for interdisciplinary design, development and evaluation.
System Architecture Video Locations Camera 1 (Fixed) Camera 2 (Fixed) Color Tracking Color Tracking Motion Tracking Motion Tracking Calibrated Video Camera 3 (PTZ) Camera 4 (PTZ) Color Tracking Beam Former Face Tracking Auditory Localization Face Tracking Video More Sensors Room Manager Face Recog.
Illinois Institute of Technology The application would run on PDAs or Tablet PCs Provide users with general campus information while guiding the user around the campus Maintain continually awareness of the user ’ s current location and intent, thereby adapting the tour to the user ’ s own personal preferences and context. Hawk Tour — A Context-aware Visitor Guide
Specific of Hawk Tour Hawk Tour uses the Ekahau Positioning Engine which makes use of the received signal strengths from WiFi access points to determine positions of the user Use 「 Scarlet 」 to collect and provide context information
Scarlet — A framework for context-aware computing Separate infrastructure functionality with application-specific functionality Non Functional Requirements Scalability Modularity Cross platform Security Extensibility Ability to Evolve Quality of Service Fault Tolerance Mobility User Friendly Interface Functional Requirements Context collection Context Storage/Management Context Subscription/Delivery Context Analysis/Composition Ability