Using mobile code interfaces to control ubiquitous embedded systems

Devices controlled by embedded computers are becoming an integral part of our everyday life, as processor and memory capacities continue to increase while their cost decreases. In some embedded systems, however, the limited input and output capacities are beginning to restrict the design of complex functionality. Furthermore, as wireless communication devices are becoming commonplace even in embedded systems, the communication and interoperation between different systems will be increasingly important in the future. This paper describes a flexible, yet powerful concept that explains how a mobile code can be conveniently utilized by mobile users to control ubiquitous and diverse embedded systems in different environments. Apart from providing flexibility, the concept also aims to keep the embedded systems as simple as possible. We will illustrate the concept by presenting as an example a virtual user interface for a videocassette recorder. We will also discuss the possible benefits and drawbacks of the system. The concept described here can be extended to allow the mobile code to be used as interconnecting "glue" in diverse embedded systems. This glue could connect systems from several manufacturers to create smart environments that can be controlled by a single simple device.