Network abstractions for context-aware mobile computing

Abstract

Context-aware computing is characterized by the ability of a software system to continuously adapt its behavior to a changing environment over which it has little or no control. Previous work along these lines presumed a rather narrow definition of context, one that was centered on resources immediately available to the component in question, e.g., communication bandwidth, physical location, etc. We explore context-aware computing in the setting of ad hoc networks consisting of numerous mobile hosts that interact with each other opportunistically via transient wireless interconnections. We extend the context to encompass awareness of an entire neighborhood within the ad hoc network. A formal abstract characterization of this new perspective is proposed. The result is a specification method and associated context maintenance protocol. The former enables an application to define an individualized context, one that extends across multiple mobile hosts in the ad hoc network. The latter makes it possible to delegate the continuous reevaluation of the context and the performance of operations on it to some middleware operating below the application level. This relieves application development of the obligation of explicitly managing mobility and its implications on the component's behavior.