Patent ID: 7133677

Claim:
A method for selecting a communication system to be used by a mobile unit to conduct a data session, the method comprising: a) determining a set of valid terrestrial wireless communication systems available to the mobile unit, the set of valid terrestrial communication systems including at least two disparate types of communication systems; b) selecting a communication system from the set of valid terrestrial communication systems; wherein the method is performed while the mobile unit is conducting the data session using a serving wireless communication system, the serving wireless communication system being in the set of valid terrestrial wireless communication systems; and c) performing a hand-off of the mobile unit from the serving wireless communication system to the selected communication system, if the step b) does not select the serving wireless communication system; wherein the step b) includes the following, b1) assigning a score to each respective communication system in the set of valid terrestrial wireless communication systems, b2) determining a candidate system for each of the at least two disparate types of communication systems, the candidate system being determined from the set of valid terrestrial wireless communication systems based on the assigned scores, and b3) applying at least one preference rule to the assigned scores of the candidate systems determined in the step b2) to obtain the selected communication system.