In recent years, the concept of the software radio has been put forward by the international communication society. It is well known that software radio will play an important role in third generation wireless communication systems. But until now there is not an acceptable concept of software radio. How to make software radio be applicable authentically, and how to develop its ascendancy? This paper introduces some new ideas about the key issues of software radio, including software radio architecture and its hardware platform, and it focuses on the design considerations of the hardware platform. Conventional software radio systems use pipeline architecture, which is not scalable and cannot fulfill the inherent requirements of software radios. In this paper a new layer structure of the hardware platform is proposed. It is an open architecture with flexibility and scalability. Then three schemes for hardware platform realization are introduced: bus architecture, switched network architecture, and fat tree architecture. An extensive analysis on advantages and disadvantages of each architecture is given. Then an application example is proposed. The switched network architecture is applied in the cellular wireless communication systems. The basestation is divided into four components according to their functions: antenna, IF, baseband, and control, which are connected by the ATM network. We call this virtualization of wireless communication systems. This will bring great benefits such as fast handoff, easily realization of different macrodiversity algorithm.