Wireless computational models: mobile agents to the rescue

Wireless mobile computing breaks the stationary barrier and allows users to compute and access information anywhere and anytime. However, this new freedom of movement does not come without new challenges. The mobile computing environment is constrained in many ways. Mobile elements are resource-poor and unreliable. Their network connectivity is often achieved through low-bandwidth wireless links. Furthermore, connectivity is frequently lost for variant periods of time. The difficulties raised by these constraints are compounded by mobility that induces variability in the availability of both communication and computational resources. These severe restrictions have a great impact on the design and structure of mobile computing applications and motivate the development of new computing models. To this end, a number of extensions to the traditional distributed system architectures have been proposed previously. These new software models, however, are static and require a priori set up and configuration. This in effect limits their potential in dynamically serving the mobile client; the client can not access a site where an appropriate model is not configured in advance. The contribution of this paper is twofold. First, the paper shows how an implementation of the proposed models using mobile agents eliminates this limitation and enhances the utilization of the models. Second, new frameworks for Web-based distributed access to databases are proposed and implemented.