A method for a radiotelephone to scan for a higher priority (including home)
public
land mobile network (PLMN) without searching in all possible RATs and frequencies
includes a first step of establishing an inclusive list of all frequencies in all
radio access technologies (RATs) in use by the higher priority or home public land
mobile network. A next step includes camping the radiotelephone on the higher priority
or home PLMN. A next step includes obtaining the inclusive list from the establishing
step by the camped radiotelephone from the higher priority or home PLMN. Afterwards,
when the radiotelephone roams to a lower priority visited PLMN, it can begin scanning
for the home (and higher priority) PLMN using only those frequencies from the inclusive
list, thereby saving battery power.