Toward Wide Area Interaction with Ubiquitous Computing Environments

The overall idea: to unify abstractions exposed by existing ubicomp systems to provide a coarse gained interface for application interfacing.

Two impediments to wider deployment of ubicomp environment

1. supporting users and applications withing single administrative or user domains
2. lack of a shared model for ubiquitous computing

The considered model for the initial version of web service based middle ware:

• Environment Model
• Through service discovery
• Through a component that handles more complex models of the environment
• Related aspects
• Environment State
• Environment Meta-state
  
• Environment Implementation link: the set of software components
• Event sources
• Context sources
• Services
• Entity Handler
  
• Entities
• Context
• Values
• High level inferred context
• Services
• Entity relationships
• Events
• Data or content

Environment profiles: to provide semantic enrichment

• entities
• services
• context
• events
• content

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Thoughts:
The paper proposes a bottom up integration of services the functionalities of middlewares with the requirements of an environment. The object in an environment are classified as discussed and the relations between them are established. Based on the requirements of users, rules are defined in the form of Jena rules that can extract the concepts of integration from ontologies and identify what components can be used for what services. The ontology preserves the relationships between the entities, their contexts, and the components.

The reasoner then identifies the set of appropriate components that have to be composed in order to provide the right combination for the request of the environment to be processed.

The problem with their approach is that they have chosen a bottom up approach to bind the components to the concepts of user needs. This makes the whole design very much dependent to the way the composition has been defined in the ontology, thus in case a relationship between the components changes, the whole design will lose its validity and the whole ontology needs to be changed.

On the other hand, this doesn't provide any possibility for component reuse cause the design is bottom up which means the components drive the design as opposed to having the design driving the components. So, it is not possible for the modules to be reused, but instead the whole system can be replaces, making its scalability absolutely questionable.

furthermore, for each new system a new integration model should be defined and thus a whole rework at the level of system design also should be done. so this new architecture doesn't solve the problem of adaptability to the new domain, it just makes it uniquely possible for different systems in different domain to choose the same technology to connect to an environment. This is not the role of a broker tho, is it?