A Rule-Based Approach Towards Context-Aware User Notification Services Describe the topic in two sentences Richard Etter (Fraunhofer IPSI) Patricia Dockhorn Costa (TELIN) Tom Broens (TELIN)

Pervasive Computing Environments Users are surrounded with ubiquitous communication and information technology. Unobtrusive services assist users in their daily lives. Context awareness has emerged as a central element in pervasive computing. Notification services are key applications.

Requirements for a User Notification Service Current middleware provides unified ways to subscribe to and manage context data. Key Issues: A flexible, efficient and convenient mechanism to allows user-applications to specify what changes in the environment should be notified to them. Tailor the user notification to the user’s context.

ANS - A Rule-Based User Notification Service A rule-based approach relieves user-application developers from regarding and logically combining multiple context sources in their application. ANS provides an expressive and simple language that enables users (application developers) to state what they are interested in. ANS provides notifications based on the user’s preferences and their current context

Design of ANS What has been implmented? How? Give some implementation details (webservice) Note: ws eventing? Note: open source?

ANS Rule Language The focus of the rule language is on the following qualities: Expressive power: the language permits the specification of complex event relations. It allows the use of logical connectives (e.g., AND, OR, NOT) on conditions to build compound conditions. Convenient use for application developers: It provides high-level constructs that facilitate event compositions. Extensibility: The language allows the addition of new predicates to accommodate events being defined on demand.

ANS Rule Language Clause Semantics Upon When Do Event part: models an occurrence of interest in the context Condition part that specifies a condition that must hold prior the execution of the action Action part which consists of notification invocations. Select Allows the selection from a collection using filtering expressions Scope Allows parameterization of rules always, once, from <start> to <end>, to <end>, <n> times, frequency <n> times per <period>

ANS Rule Language Examples Notify Jerry if his computer is online when he leaves his room. Upon leaveRoom (Jerry, Room101) When IsOnline (Jerry) Do Notify (Jerry, “Jerry, your computer has been left on”) XML schema available

Outlook The Awareness and Notification Service is part of the middleware EU-project AMIGO. A first version of the service is currently being deployed in the AMIGO Ambient Intelligence Environments.

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