Number : WUCSE-2005-35 2005-08-02 SPAWN : Service Provision in Ad-hoc Wireless Networks

The increasing ubiquity of wireless mobile computing platforms has opened up the potential for unprecedented levels of communication, coordination and collaboration among mobile computing devices, most of which will occur in an ad hoc, on-demand manner. This paper describes S PAWN, a middleware supporting service provision in ad-hoc wireless networks. The aim of S PAWN is to provide the software resources on mobile devices that facilitate electronic collaboration. This is achieved by applying the principles of service oriented computing (SOC), an emerging paradigm that has seen success in wired settings. S PAWN is an adaptation and extension of the Jini model of SOC to ad-hoc networks. The key contributions of S PAWN are (1) a completely decentralized service advertisement and request system that is geared towards handling the unpredictability and dynamism of mobile ad-hoc networks, (2) an automated code management system that can fetch, use and dispose of binaries on an on-demand basis, (3) a mechanism supporting the logical mobility of services, (4) an upgrade mechanism to extend the life cycle of services, and (5) a lightweight security model that secures all interactions, which is essential in an open environment. We discuss the software architecture, a Java implementation, sample applications and an empirical evaluation of the system.