IMPROVING THE FAULT-TOLERANCE OF GSM NETWORKS

A PCS network constantly frocks the locations of the mobile stations s o that incoming calls can be delivered to the target mobile stations. In general, a two-level database system is used to store location info rmation of the mobile stations. When the location databases Fail, inco ming calls may be lost. This article describes the standard GSM databa se failure restoration procedure which reduces the number of lost call s. Then we propose an efficient VLR identification algorithm for the H LR failure recovery procedure, which utilizes mobile station movement information to speed up the recovery procedure.