TRIGGERING A MORE AGGRESSIVE PLMN SEARCH ALGORITHM WHEN IN A VISITED PLMN ADJACENT TO THE HOME PLMN

摘要

When wireless user equipment, UE, such as a cell phone, a smart phone, and/or the like, travels to an area outside its home network, the UE may perform a roaming operation and search for and couple to a visited network. Most user equipment are configured to automatically roam to the visited network in accordance with a standard, such as 3GPP TS 23.122. The UE, carried by a user on a daily commute to work may encounter roaming when crossing a national border where the UE may roam for an extended period of time in a visited PLMN even though a home PLMN may still be able to serve the UE. Since cellular roaming charges can be very high, the application aims at reducing visited network roaming in such cases. This aim is achieved by defining a so-called "border area" and when the UE is located in this "border area", a modified PLMN selection algorithm is triggered which searches home PLMNs with a higher frequency than the default frequency.