Integrating Web services and mobile agent systems

Middleware supports based on mobile agents (MAs) have recently emerged with the goal of allowing application developers to easily manage and control the properties and behaviors of mobile systems, especially in novel wireless and ubiquitous scenarios. Several MA systems have grown independently with no widely recognized standardization and still lack functions for easy integration. The primary consequence is that one MA platform tends to offer middleware facilities scarcely compatible with other MA systems. Moreover, MA tools are sometimes difficult to employ by common users who have to overcome a significant knowledge gap before properly exploiting MA-specific functions. The paper proposes a solution to open up the usage of MA systems via the bridge of the emerging Web services (WS) standard technology to achieve interoperability. We have developed an integration infrastructure, called WSMI, with the twofold goal of exporting the MA functions with a WS interface and of simplifying the access to legacy WS components from any MA system. This promotes the uniform access to different MA system functions, independently of the specific MA implementation. We have thoroughly evaluated the WSMI prototype performance, also by comparing the WSMI integration functions with similar non-WS-based facilities: the increased dynamicity and openness of our integration infrastructure have demonstrated to largely counterbalance the overhead introduced by WS adoption.