Patent ID: 6961583

Claim:
A multi-mode mobile station comprising: a radio frequency (RF) module capable of accessing a first radio system using a preferred radio protocol and further capable of accessing a second radio system using a less-preferred radio protocol; and processing circuitry associated with said RF module capable of determining the quality of first control channel signals received from said first radio system and determining the quality of second control channel signals received from said second radio system, wherein said processing circuitry determines the quality of said first control channel signals by determining a number of control messages received during a predetermined time period in a first control channel in which said first control channel signals are transmitted and further determining if said number of received control messages exceeds a minimum threshold value, and said processing circuitry, in response to a determination that the quality of said first control channel signals is sufficient to prevent said multi-mode mobile station from losing access to said first radio system, further determines from the quality of said first control channel signals whether said first radio system is able to provide an optimum signal quality.