Method and apparatus for using a radio access technology in a mobile station employing a removable memory device

A mobile station comprising:

• a transceiver that is configured to wirelessly detecting a radio access technology (RAT) and a public land mobile network (PLMN) broadcasting on that RAT to produce a detected PLMN and RAT combination;
• one or more memory devices, wherein the one or more memory devices comprise a removable memory device that is configured to maintain a data file that includes a prioritized listing of one or more PLMN and RAT combinations and wherein the one or more memory devices further maintain a radio access technology (RAT) preference rule;
• and
• a processor that is configured to:
• determine a type of the removable memory device;
• in response to determining that the removable memory device is a type that would maintain information on the detected RAT, determine a priority of the detected PLMN and RAT combination relative to one or more other PLMN and RAT combinations based solely on the prioritizations included in the data file in the removable memory device;
• in response to determining that the removable memory device is a type that would not maintain information on the detected RAT, determine a priority of the detected PLMN and RAT relative to one or more other PLMN and RAT combinations based on a RAT preference rule separate from, and in conjunction with, the listing of PLMN and RAT combinations in the data file in the removable memory device;
• and
• select a PLMN and RAT for radio communications based on the determined priority of all the found PLMNs and RATs.