Supporting Environment Configuration with Generic Role Assignment

Due to the fact that distant objects are often less relevant to an application than objects in the proximity, middleware systems for pervasive computing typically exploit locality to improve efficiency. To do this, they configure the environment by introducing logical boundaries that reduce the number of interacting devices. Yet, in cases where applications require the interaction with distant objects, the boundaries become an artificial barrier that must be overcome by supplemental mechanisms. In this paper, we show how this problem can be avoided by using role assignment as a generic mechanism for environment configuration. To do this, we first derive the requirements for configuring a pervasive computing environment. We discuss how these requirements can be met by means of role assignment. To evaluate the approach, we present a prototypical implementation which we use to quantify the resulting overheads. The results indicate that role assignment enables a more flexible definition of boundaries at a low cost.