CoCA: A Collaborative Context-Aware Service Platform for Pervasive Computing

CoCA: A Collaborative CoCA: A Collaborative Context-Aware Service Context-Aware Service Platform for Pervasive Platform for Pervasive Computing Computing

Dejene Ejigu , Marian Scuturici , Lionel Brunie Laboratoire LIRIS-UMR-CNRS 5205, INSA de Lyon,

7 avenue Jean Capelle, 69621 Villeurbanne cedex, France

IDS Lab.

Presented by Sang-Keun Lee

Copyright 2008 by CEBT

IntroductionIntroduction

Nowadays…

The emergence of a computing model for mobile ad-hoc networks in pervasive environments

The wide spread of pervasive enabling technologies and the availability of computing enabled handheld appliances

However, the user should not be disturbed by such devices

Context awareness is among the core components of these

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Pervasive Environment is characterized by

– dynamicity, heterogeneity and ubiquity of users, devices and resources, ad-hoc connection among the devices and sensors

GCoM modeling deals with

– how context data is collected, organized, represented, stored and presented

CoCA service

– interprets and aggregates the low level context values to a more meaningful high level context

– performs reasoning about the context and passes decisions about the actions to be triggered

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– stores knowledge and decisions corresponding to the context instance into knowledge repository for future reference.

Basic elements of a pervasive computing environment



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The objective in this work is to propose and investigate architecture for context-aware services focusing on context reasoning in pervasive computing environment using semantic ontology and collaborative approaches.


Related WorksRelated Works

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Application specific approaches

Abowd G., Atkeson, Hong C.,J., Long S., Kooper R., Pinkerton M.“Cyberguide: A Mobile Context-Aware Tour Guide”, Wireless Networks, 3:421--433, 1997

Kindberg T., Barton J.“A web-based nomadic computing system”, Computer Networks, 35(4):443–456, 2001.

Priyantha N., Miu A., Balakrishnan H., Teller S.

“The Cricket Compass for Context-Aware Applications”, Proc. of 7th Annual ACM/IEEE International Conference on Mobile Computing and Networking (MobiCom 2001), Rome, Italy, July 2001.

Major contributions / does not allow ad-hoc communications

context-aware services are based on ad-hoc models and Dertouzos M., “The Oxygen Project” Scientific American, Vol. 281(2), Aug 99, pp. 52-63.

Cerqueira R., Hess C. K., Roman M., and. Campbell, R. H. “Gaia: A Development Infrastructure for Active Spaces”, Workshop on Application Models and Programming Tools for Ubiquitous Computing in conj. with UBICOMP 01, Sep 01.

Semantic web technology

Chen H., Finin T., Joshi A. “An ontology for context-aware pervasive computing environments”, Special Issue on Ontologies for Distributed Systems, Knowledge Engineering Review, Acapulco MX, August 2003.

Context ontology for reasoning and representation

Wang X., Zhang D. Q., Gu T., Pung H. K. “Ontology Based Context Modeling and Reasoning using OWL”, workshop on context modeling and reasoning at IEEE International Conference on Pervasive Computing and Communication , Orlando, Florida, March 2004.

Service based framework/ middle ware solution

Gu T., Pung H. K., Zhang D. Q. “A Service-Oriented Middleware for Building Context-Aware Services”, Journal of Network and Computer Applications, 28, 2005, pp. 1–18.

Others

MARKS, RCSM


Related WorksRelated Works

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CoCA: A Collaborative Context-Aware Service Platform for Pervasive ComputingEjigu, Dejene Scuturici, Marian Brunie, Lionel Lab. LIRIS, UMR-CNRS, Villeurbanne;

An Ontology-Based Approach to Context Modeling and Reasoning in Pervasive ComputingEjigu, Dejene Scuturici, Marian Brunie, Lionel Lab. LIRIS-UMR-CNRS, INSA de Lyon;

Hybrid Approach to Collaborative Context-Aware. Service Platform for Pervasive Computing. Dejene Ejigu. Laboratoire LIRIS-UMR-CNRS 5205

Semantic approach to context management and reasoning in ubiquitous context-aware systems Ejigu, Dejene Scuturici, Marian Brunie, Lionel Laboratoire LIRIS-UMR-CNRS, 5205


The CoCA Service PlatformThe CoCA Service Platform

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Interface Manager

Manages a UI and interface between the CoCA platform and other modules

Data Source

Responsible to provide necessary data to the core service (GCoM)

Core Service

Responsible to provide the core context aware service after reasoning on the components

Supplementary Service

Knowledge discovery & Collaboration service

The Platform aims at acquiring and utilizing context information to provide appropriate services

E.g) A cell phone is always set to vibrating mode when its holder is in the libraryIt filters and sends useful

contexts to the context repository

It Keeps the rules in the rule repository

It consists of domain dependent/independent

ontology

Reasoning -> Decision & ActionInterpretation, Aggregation


The CoCA Service PlatformThe CoCA Service Platform

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The Platform uses Contexts, rules, and ontology combined as an input


Discussions and Usage ScenarioDiscussions and Usage Scenario

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Activity diagram shows details of invocation and flow of activities in the CoCA service platform

2x2 partitions in the diagram show the services and the units responsible for each activity

Protégé ontology development tools and Jena framework API’s are used to implement

Scenario – Pervasive Campus Aware Smart Onlooker example (PCASO)

Scenario of a university campus where research students and professors are involved

Regular meetings, informal and spontaneous meetings and discussions are important for the advancement of their work

Discussion can take place among two or more depending on the relevance of their work


QuestionsQuestions

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When do they make such a meeting?

How can only those available are informed about someone else’s interest to discuss about a specific subject matter during his tea break?

How can a student know when his professor is in the tea room, in his office?

What type of messaging method is appropriate to send such information to a particular person located at a particular place at a particular time?


Ontology, Context, Rules, …Ontology, Context, Rules, …

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Ontology, Context, Rules, …Ontology, Context, Rules, …

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In GCoM model

Ontology representation using OWL

Context representation using RDF

Rule representation using Jena

Sample Query to select the phone for which the action has to be triggered/fired for “Silent” mode setting can be given as:


Trace of Reasoning ProcessTrace of Reasoning Process

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Peer Collaborations in the Peer Collaborations in the NeighborhoodNeighborhood

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Storage and processing of context data to knowledge is Highly resource intensive

Ubiquitous devices have scarce resources

Collaboration manager in the CoCA service platform lets devices share resources like context, rules, ontology, processor, memory, etc. to solve computing problems


Conclusion and Future WorkConclusion and Future Work

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The authors proposed a data independent collaborative context-aware service platform

Prototype has been implemented

Hybrid Approach to Context-aware Service Platform (2008.1)

Combine RDB & Ontology approaches

What is the difference between CoCA and Our approach (a.k.a Alliver)

Copyright 2008 by CEBTIDS Lab. 16

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CoCA: A Collaborative Context-Aware Service Platform for Pervasive Computing