On Event-Based Middleware for Location-Aware Mobile Applications

A number of techniques including location-independent announcement and subscription coupled with location-dependent filtering and event delivery that can be used by event-based middleware to support location-aware mobile applications in which highly mobile components come together dynamically to collaborate at some location are presented.

Abstract

As mobile applications become more widespread, programming paradigms and middleware architectures designed to support their development are becoming increasingly important. The event-based programming paradigm is a strong candidate for the development of mobile applications due to its inherent support for the loose coupling between components required by mobile applications. However, existing middleware that supports the event-based programming paradigm is not well suited to supporting location-aware mobile applications in which highly mobile components come together dynamically to collaborate at some location. This paper presents a number of techniques including location-independent announcement and subscription coupled with location-dependent filtering and event delivery that can be used by event-based middleware to support such collaboration. We describe how these techniques have been implemented in STEAM, an event-based middleware with a fully decentralized architecture, which is particularly well suited to deployment in ad hoc network environments. The cost of such location-based event dissemination and the benefits of distributed event filtering are evaluated.