Pervasive Computing 通訊所 鄭筱親

Outline  Introduction  Context Awareness  Recent Research  Future and Conclusion

Introduction (1)  The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it Mark Weiser

Introduction (2)  普及計算 == 無間計算 時無間 -----anytime 空無間 -----anywhere 罪器無間 ---any devices 平等無間 ---any race 生死無間 ---service forever

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

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

The MIThril RealTime Context Engine

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?

Recent Research  AHRI  HawkTour

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.

AHRI  Gesture Pendant Simplified home control

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

Separation of Application and Infrastructure

The Scarlet System

Future and Conclusion  我們的未來不是夢 ?

---The End-- Thank you for your listening!