Modeling Analysis on the Visitor Locations Register in 3G

In this paper, we researched the status of the Visitor Locations Register (VLR) in the third generation communication system (3G). Basing on automata theory, we offer the statues modeling of the VLR, is called Visitor Locations Register Automata (VLRA), which formally describes the states, the behavior, and the variation of the VLR in the authentication protocol. Finally, we formally analyzed the VLRA in the authentication process.