The growing demand for wireless access has led to the emergence of all kinds of standards for wireless communication, each of which has its own special requirements. The future transceiver equipment of mobile station (MS) should support the operation of these systems from the viewpoint of system compatibility. In this case, multi-mode, multi-band operation is required for user's convenience. Moreover, realization of small size and low power consumption handy terminals is necessary. These are the trends that have led to continued discussion about software radios (also called software defined radio, SDR). SDR is emerging as a potential programmatic solution: a software implementation of the user terminal which is able to reconfigure such terminal to suit the changing radio environment as for example in the case of global roaming. There are a great number of international organizations and forums for software defined radios around the world.  In this thesis, a generalized state diagram of a SDR reconfigurable, multi-mode mobile station that could roam/handoff between different wireless systems is developed. A detailed description of the power-up, roaming and download operation for this reconfigurable MS is presented. Furthermore, its roaming connection establishment acquisition time in different scenarios is evaluated. Specifically, the relationships between the roaming acquisition time and system resource blocking probability, mobile station resource blocking probability, packet successful transmission probability over wireless channel and signaling bit rate over the universal base station channel in different cases and design scenarios are analyzed. Such evaluations are important for prior design of SDR mobile terminal and universal base station in global roaming situations.