This paper describes the design considerations of and preliminary conclusions drawn from an ongoing project dealing with the design of a software architecture for a family of so-called smart wireless communication devices (SWCDs). More specifically, based on an existing hardware platform, the software architecture is being modeled using UML in conjunction with suitable framework and product line modeling approaches to achieve a high degree of flexibility with respect to variability at both the hardware and application software end of the spectrum. To this effect, the design is split into a middleware framework encapsulating specifics of the underlying hardware platform and OS, and product line modeling of a comprehensive, versatile application on top of it.