1. Communication within AmI

2. Gent, 21 maart 2005 Communication as a ubiquitous activity The Three Scenarios:  Instant Messaging  Integrated Traffic Information  The Museum Visit Communication is a basic activity in all scenarios. The characteristics of communication are subject to usage requirements and the context of deployment Goal: A communication service supporting context-driven adaptation and integration with other services

3. Gent, 21 maart 2005 Communication as a ubiquitous activity Communication Service: Properties  Message format: plain text – image – audio – video Traffic Information: video output or text input not likely Museum Visit: covers all multimedia aspects  Communication partners: users – devices Instant Messaging: Friends talking to each other Museum Visit: Automatic registration in the entrance hall  Employing different kinds of (wireless) transport media Range Bandwidth

4. Gent, 21 maart 2005 Communication as a ubiquitous activity Communication Service: Properties  Uni- or bi-directional communication Museum Visit: nowadays mostly one-way communication Instant Messaging: real interaction  Resource requirements and current availability Memory – processing power – bandwidth Changes may trigger service adaptation  I/O requirements Traffic Information: speech output is preferable  Discovery: Interoperability with other services Traffic Information: interaction with a text-to-speech service Instant Messaging: video streaming using a GPRS service

5. Gent, 21 maart 2005 Communication as a ubiquitous activity

6. Gent, 21 maart 2005 Communication as a ubiquitous activity Communication Service: Example  Type of communication depends on the available bandwidth  Broadband connection is shared  Message events from the Internet Gateway Service notify all clients about a change in bandwidth  Components: Audio Encoder and Decoder: Adaptable components for (de)compressing the audio stream (high, medium or low quality) Video Filter: Optional component for reducing the video frame rate or resizing. Video Encoder and Decoder: Adaptable components for (de)compressing the video stream (high, medium or low quality). Controller: (de)multiplexes text, speech and video, and sends/receives the combined data stream.

7. Gent, 21 maart 2005 Communication as a ubiquitous activity Communication Service: Adaptation  When? @ Deployment time @ Runtime  How? Use a component-based development methodology (Near)-optimal distributed deployment of all components Adapt functionality: enable – disable – replace components Relocate components  Using transparent proxies  (Strong) code mobility  Why? Provide optimal quality of service

8. Gent, 21 maart 2005 Communication as a ubiquitous activity Collaboration with other partners:  Who? VUB/SSEL: Code generation of components VUB/PROG: Proof of concept interoperability for code mobility UGent: Performance analysis of components LUC: User interface generation as front end for services  How? Draco: Common component-based middleware in Java Support for  Resource management and contract checking  Live-updates  Distributed-deployment of components

9. Gent, 21 maart 2005 Communication as a ubiquitous activity