We propose a new mobile computing paradigm, in which an intelligent card (called an Ward) plugged into a mobile device serves as the centerpiece that provides enhanced networking and application capabilities to the mobile host. Placed between a mobile host and traditional network interfaces, Ward is device independent, easy to program, and offers enhanced security. This paper describes the overall concept of Ward, and the key elements in its hardware and software architecture. The hardware discussions focus on a particular design that we have put together for an actual prototype iCard. We share with readers the rationales behind various choices made in this design. On the software side, we have been developing application programs to be loaded onto the iCard using a StrongARM reference board. To demonstrate the strong potential of the new paradigm represented by Ward, we show how Ward is able to provide Mobile IP functions without making any modifications to the host machines.
