Smart Campus System a Proposal for a Context-Aware Application Sangkeun Lee Sungchan Park IDS Lab, SNU 1

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Smart Campus Systema Proposal for a Context-Aware Ap-plication

Sangkeun Lee

Sungchan Park

IDS Lab, SNU

Copyright 2008 by CEBT

Introduction

Smart Campus System

supports development, maintenance, and delivery of context-aware services in university campus

aggregates context data in university campus so that context-aware application can exploit them

provides model and tools for designing context-aware services running on our system

Why do we choose university campus as a domain?

it provides good foundations for operating context-aware services

is well organized area with large size, and large number of people spends most of their time within the area

Semantic Tech & Context - 2


Motivating Scenarios

we built some various realistic context-aware application scenarios, and studied the requirements of our system based on the scenarios

Each scenario has its own characteristics which show what our system should support.

4 Scenarios

Preparing iced coffee

Bus stop

Cafeteria information

Personalized department office



Motivating Scenarios: Preparing iced Coffee

Scenario

On a very hot and humid day, A is returning to his dormitory room by shuttle bus. When 5 minutes left to arrival, his PDA rings alarm sound with displaying the following message: “It is very hot day. Is it O.K. to prepare a cup of iced coffee at your room? Yes/No” He clicks “Yes” and the coffee pot in A’s room starts to make some iced coffee. When A arrives at his room, U-home terminal attached on wall notifies that the iced coffee is prepared with voice.


Device Collaboration

possibility of different device composition


Motivating Scenarios: Bus Stop

Scenario

A just has arrived at the bus stop. At the moment, A’s cellular phone rings alarm sound with displaying the following message: “Waiting time info: circulation shuttle bus arrives in 10 min. commuter bus arrives in 5 min.”

A clicks on ‘bus waiting time info’, PDA displays the waiting time information of the nearest bus stop.


real-time synchronization with real world

Level of autonomy


Motivating Scenarios: Cafeteria In-formation

A is sitting at his desk in his laboratory, and it is 11:50 AM—it is close to lunch time. He usually checks the number of available seats in the cafeteria or length of waiting queue. But he does not do so today since he is busy now. At that moment, the following message is displayed on the monitor of his desktop computer: “The lunch time is close. Would you like to check the current status of the cafeteria? Yes/No”


Prediction based on historical user record


Motivating Scenarios: Personalized Depart-ment Office

A has forgot applying “graduation exam”. If he does not apply by tomorrow, his graduation will be delayed one semester. When A comes to laboratory at 10 o’clock AM and logs in his desktop computer, the monitor displays the following message: “Notification from department office of computer science: You should apply “graduation exam” by tomorrow. If not, some problem can occur related to your graduation.”


Virtual information as context information

Context Fusion (Virtual + Physical Sensor)


Common Issues

Terminal selection

If the user sits at the desk, the desktop computer is most relevant terminal. If the user carries his PDA, the PDA is most relevant terminal

Identifying the entities

System should be able to identify many entities, like shuttle bus, cafeteria, and students and so on

RFID Tags, Distributed Sensors

Processing user feedback

important for maintain and enhancing services

The infrastructure should support the development



Smart Campus System

Our Smart Campus System

Gathers context-information from various sources

Handles the abstraction level of context data

Provides efficient ways of storing and managing context data

Is flexible and easily configurable

– System administrators can easily add new context-aware services or configure existing services

Provides the most appropriate service or content to users without user’s too much intervention

Supports graphic user interfaces for mobile and desktop environments – both for system administrator and users



Technical Issues

Centralized (Context Server) vs. Decentralized (P2P Network)

Dealing with Heterogeneity

many different devices should be able to smoothly communicate with each other

Abstraction and standardization



Technical Issues

Performance & Scalability

If the system can’t support acceptable performance and scalability, then it can’t be a practical and useful system

many sensors generate large number of signals, and the signals should be handled in real-time

Historical context data & User behavior log

Context-aware services are basically real-time based, however, historical context data and user behavior log can be used as very useful data for the services

Privacy Protection

some users may feel uncomfortable that the system can use or open their information without any notice

privacy policy is required



Smart Campus System

We reckon the ‘Context Server’ approach as a more suit-able method for our Smart Campus System

Campus System can be unified to the legacy system

the congestion problem, and low fault-tolerance problem can be relatively easily solved than the problems of P2P approach like handling dynamicity of constructing commu-nication networks

We present Server-Client Architecture



Smart Campus System - Server

The server-side system is the core of Smart Campus System and responsible for:

Mediating communication among devices

Gathering context data from various sources

Handling the abstraction level of context data

Managing context data

Triggering services based on service rules

Running service descriptions

Managing service descriptions in the service repository

Logging historical context data and user behavior

Providing graphic user interface for users and system administrator




Interface

works as a communication abstraction layer among devices

virtual devices which are actually software modules can be used just like other devices through the interface

Context Manager

controls the abstraction levels of context information based on predefined Context Rules

manages context data in database

To enable the semantics of context data, Smart Campus System uses the Vocabulary Ontology

Privacy Manager

protects illegal access of context data based on privacy policy.

Privacy policy specifies what context data is allowed to whom or what devices or services.

When a device or a service requests context data to Context Manager, Privacy Manager checks if the requested context data is allowed. Context Manager provides the data only when it’s allowed according to the privacy policy.




Service Trigger

monitors high-level context information transformed by the Context Manager.

A Service Rule specifies what kind of service should be triggered in what context.

Service Repository

is where context-aware service descriptions are stored.

A service description is represented in Context-Aware Service Description Language (CASDL).

CASDL is a script language for describing details of such as the required context data for performing the service, detailed service process, communication among devices, and the final output format.

Service Processor performs actual service processes according to the service description. Service Processor sends the processed results to the target service terminal specified in the service description.

Log Manager manages all the logs of changes in context data, user behavior





Log Manager

Real World EnvironmentWWW

Location

Temperature PressureAltitude

Sensor Sensor Sensor Virtual Sensor…

Interface

Humidity

Device (Client)Device (Client)

Device (Client)Device (Client)

Context Manager

Service Trigger

Service Processor

ContextData

Vocabulary Ontology

Service Repository

ServiceDescription

ContextRules

ServiceRules

Context-aware Service Description Language (CASDL)

Privacy Manager PrivacyPolicy

Log


Smart Campus System - Client

The client-side system

Relatively Simple

should be able to be deployed in mobile devices,

should have light and simple architecture

The client-side system is responsible for:

Communicate with the server-side system

Processing the requests from the server

Providing interactive graphic user interface


Request Processor

Interface GUI

Server

Legacy System


Service Process Flow


Sensors in Shuttle Bus send signals to Smart Campus Server:

Temperature, User’s presence, … Context Manager abstracts the signal and store in

database:

Ex) Temperature > 25 & Humidity > 70% => Weather is hot

Service Trigger monitors catches the situation and trigger(create a service instance) “Preparing iced cof-fee” service according to service rules

Service Description of “Preparing iced coffee” is loaded into Service Processor

Service Processor interacts with other devices, accord-ing to loaded service description: Coffee pot, Ice Maker, …

Sensors in user’s room notices that the user has ar-rived and send the signal to Smart Campus Server

U-home Terminal notifies the user when the iced coffee is ready

End of Service

Smart Campus System

CASDL


Development Plan



Conclusions

We presented

the proposal of Smart Campus Project for providing context-aware services in university campus

motivating scenarios

main functionalities

technical issues and showed how we will handle the issues.

high level architecture of Smart Campus System and Service Process Flow

Although we presented a domain-specific application proposal, the ultimate aim of this project is to explore unseen issues on realizing context-aware services

We conclude that actual implementation will also provide us good insight for realizing general purpose large-scale context-aware systems


Documents

Smart Campus System a Proposal for a Context-Aware Application Sangkeun Lee Sungchan Park IDS Lab, SNU 1