Towards a Middleware for Generalised Context Management

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Towards a Middleware for Generalised Context
Management
Glassey R., Stevenson G. International
Conference on Mobile Data Management 2003

• 2005.07.05
• Kim, Chang-soon
• (flsoon_at_parallel.yonsei.ac.kr)
• Dept. of Computer Science
• Yonsei University

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Contents

• Introduction
• SCI Architecture
• Structure of a Range
• Model of Composition
• CAPA An Example Implementation

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Introduction

• Definition of Pervasive Computing
• Calm technology that delivers the correct
  service to the correct user, at the correct place
  and time, and in the correct format for the
  environment with minimal user distraction.
• Key to the delivery of truly calm technology
• Contextual interactions
• Challenges
• How to collect and process context data with
  minimal user distraction
• Current status
• Developers have to spend time on low-level levels
• Previous work do no support
• Dynamic composition and flexible representation
  of contextual interaction
• Scalability and adaptability of environmental
  changes

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Introduction (contd)

• Propose Strathclyde Context Infrastructure (SCI)
• Middleware infrastructure for discovery,
  aggregation, and delivery of context information
• Focus on
• Extraction, placement, and management of context
  in the face of mobility

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SCI Architecture

• Organised into two layers
• SCINET
• Network overlay of partially connected nodes
• Range
• Concerns the contents of each node
• Consists of entities
• People, S/W, place, devices
• Responsible for
• Producing, managing using contextual
  information

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SCI Architecture (contd)

• SCINET
• Managing interactions b/w several ranges in order
  to provide appropriate contextual information
• Network overlay approach
• Provides favourable scalability and robustness
• Routing
• Avoids bottlenecks (not hierarchical
  infrastructure)
• SCINET can be created via Range discovery

SCINET
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SCI Architecture (contd)

• Range
• An area that can be described in logical and/or
  physical terms
• Effective operating range (e.g WLAN)
• Collection of adjacent rooms, entire floor of
  building
• Each range is governed by its own Context Server

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Structure of a Range

• Managing providing contextual information
  within a Range
• Components
• Context Server
• Context Entities
• Context Aware Applications
• Context Utilities
• Context Server
• Central server for management of contextual
  information within a Range
• Manages the other component
• Provide means of communication with other Range
  in the SCINET
• Maintains a central store of entity information
• Access point for CAA to interact with the
  infrastructure

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Structure of a Range(contd)

• Context Entity (CE)
• S/W component for representing (abstracting) an
  entity
• Allows non-computational entities to be included
  within the infrastructure
• Maintains
• Profile contains meta-data describing the entity
• Advertisement describing the services that can
  provide to other entities
• All CEs are registered within a range when they
  arrive and deregistered upon departure
• Context Utilities
• Set of specialist services
• Core set
• Range Service (detecting entities) / Query
  Resolver / Location Service / Profile Manager /
  Event Mediator / Registrar

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Model of Composition

• Support data composition (aggregation)
• By forming configuration
• which is an event subscription graph
• Example
• CAA(pathApp) requests the path b/w Bob and John

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CAPA an example implementation

• CAPA (Context Aware Printing Application)

4.Store query
CS
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CAPA an example implementation(contd)
CS
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Conclusion

• Future work
• Topology management of the overlay network
• Context query language
• Appropriate location model