Itinerary-Based Mobile Agent as a Basis for Distributed OSGi Services

Recently, as more and more mobile devices embedded with intelligent software become part of our daily lives, Open Services Gateway initiative (OSGi) has gained increasing attention in the development of services for such devices. However, services residing in OSGi platforms are devised specifically for the platforms' local bundles. Although several works have enhanced OSGi with various communication mechanisms that enable remote service invocations, two crucial issues pertaining to mobile computing remain to be addressed: One is limited resources of mobile devices, and the other is unstable links experienced with mobile devices. To address these two issues, we propose an itinerary-based mobile agent approach with four major features: To implement mobile agents as OSGi bundles to deliver distributed OSGi services with lower resource consumption; to extend WSDL and WS-BPEL to help developers design mobile agent itineraries; to provide an opportunistic service matchmaking mechanism allowing mobile agents to adapt to context changes at runtime; and to devise asynchronous communication mechanism to enable reliable mobile agent transmissions among mobile devices with dynamic IP addresses and intermittent connection to the Internet. Through experimental evaluations, we demonstrate that both network traffic and turnaround time of our approach are better than those of client-server ones.

1 Introduction

Open Services Gateway initiative (OSGi) [27], an open service-oriented framework, has gained increasing attention in the development of services for mobile information devices. OSGi was originally designed as a software middleware in a residential gateway to remotely control home appliances [6], [36], and dynamically download and install required services from appliance providers via the Internet. Moreover, because of the benefits of openness, modularization, extensibility, and dynamic configurability, OSGi technology has being adopted by other domains, such as Eclipse plug-in development [13], [30], mobile devices [7], and vehicles [17].