Method to prevent cellular phone from receiving control channel of wrong system

A method is disclosed for operating a mobile station (10) to obtain service from a cellular system, as is a mobile station that operates in accordance with the method. The method includes the steps of (a) scanning a set of dedicated control channels and tuning to the strongest dedicated control channel; (b) receiving a first control message (SPOM) from the dedicated control channel; (c) storing a first System Identification (SID) from the first SPOM; (d) determining if the channel number of the strongest dedicated control channel is equal to a system boundary channel number; and if yes, (e) tuning to a second strongest dedicated control channel; (f) receiving a second SPOM from the second strongest dedicated control channel and storing a second SID from the second SPOM; and (g) comparing the first SID to the second SID and if they are not equal, entering an IDLE task while remaining tuned to the second strongest dedicated control channel, else if the first SID is equal to the second SID, (h) re-tuning to the strongest dedicated control channel and entering the IDLE task while remaining tuned to the strongest dedicated control channel.