Extending the data services of mobile computers by external data lockers

Although mobile computers are becoming more and more powerful, the intrinsic features of wireless communications: poor quality, limited bandwidth, continuous disconnections, expensive communications, still limit the performance delivered to mobile users. The authors present the Locker Rent Service that allows mobile users to rent a dedicated disk space, located in the fixed network, where they can store and access their data. Besides increasing the storage capacity of mobile devices, the Locker Rent Service offers to mobile users data protection, battery power savings and various communication optimizations. The service is supported by a middleware architecture that incorporates this and other services with the general goal of increasing mobile computer capabilities and performance. The architecture is based on mobile agents and offers flexibility and adaptability with a low overhead as shown by our preliminary performance results.