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

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

Copyright  2008 by CEBT 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 Semantic Tech & Context - 3

Copyright  2008 by CEBT 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. Semantic Tech & Context - 4 Device Collaboration possibility of different device composition

Copyright  2008 by CEBT 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. Semantic Tech & Context - 5 real-time synchronization with real world Level of autonomy

Copyright  2008 by CEBT Motivating Scenarios: Cafeteria Information  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” Semantic Tech & Context - 6 Prediction based on historical user record

Copyright  2008 by CEBT Motivating Scenarios : Personalized Department 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.” Semantic Tech & Context - 7 Virtual information as context information Context Fusion (Virtual + Physical Sensor)

Copyright  2008 by CEBT 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 Semantic Tech & Context - 8

Copyright  2008 by CEBT 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 Semantic Tech & Context - 9

Copyright  2008 by CEBT 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 Semantic Tech & Context - 10

Copyright  2008 by CEBT 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 Semantic Tech & Context - 11

Copyright  2008 by CEBT Smart Campus System  We reckon the ‘Context Server’ approach as a more suitable met hod for our Smart Campus System Campus System can be unified to the legacy system the congestion problem, and low fault-tolerance problem can be rela tively easily solved than the problems of P2P approach like handling dynamicity of constructing communication networks  We present Server-Client Architecture Semantic Tech & Context - 12

Copyright  2008 by CEBT 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 Semantic Tech & Context - 13

Copyright  2008 by CEBT Smart Campus System - Server  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. Semantic Tech & Context - 14

Copyright  2008 by CEBT Smart Campus System - Server  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. Se rvice Processor sends the processed results to the target service terminal specified in the ser vice description.  Log Manager manages all the logs of changes in context data, user behavior Semantic Tech & Context - 15

Copyright  2008 by CEBT Smart Campus System - Server Semantic Tech & Context - 16 Log Manager Real World Environment WWW Location Temperature Pressure Altitude Sensor Virtual Sensor … Interface Humidity Device (Client) Context Manager Service Trigger Service Processor Context Data Vocabulary Ontology Service Repository Service Description Service Description Context Rules Service Rules Context-aware Service Description Language (CASDL) Privacy Manager Privacy Policy Log

Copyright  2008 by CEBT 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 Semantic Tech & Context - 17 Request Processor Interface GUI Server Legacy System

Copyright  2008 by CEBT Service Process Flow Semantic Tech & Context - 18 Smart Campus System CASDL

Copyright  2008 by CEBT Development Plan Semantic Tech & Context - 19

Copyright  2008 by CEBT 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 Semantic Tech & Context - 20