An improved VLR overflow control scheme for fraudulence detection

Current mobile networks adopt a two-tier database, HLR and VLR, strategy to manage users´ mobility. Since the number of users visiting a VLR coverage area changes dynamically, a VLR may overflow which results in service failure for newcomers. Although current studies have solved the overflow problem, they may lead to fraudulence problem due to cloned user. To solve this problem, we propose an improved overflow control scheme in which the system can detect the fraudulence in time. In addition, an analytic model is proposed to investigate the performance of the improved scheme.