1. A method for performing a public land mobile network (PLMN) list generation or PLMN search on user equipment having two radio frequency (RF) transceivers, wherein the user equipment is operating in a mobile communication system, the method comprising: receiving a request requesting the PLMN list generation or PLMN search; determining whether both or either of the RF transceivers is available for handling the PLMN list generation or PLMN search; selecting a dispatch rule; generating a PLMN list from both RF transceivers collaboratively or performing a search collaboratively for at least one selected operating frequency band on both RF transceivers in accordance with the request and the dispatch rule; and providing an execution result corresponding to the PLMN list generation or PLMN search by gathering results of the PLMN list or search obtained from the two RF transceivers.