Abstract: Since mobile user mobility behaviors can vary according to time periods, e.g. office-going/closing and office hours, the location management traffic load for tracking user positions is also a function of time. The transient characteristics of location management traffic vary according to users' initial starting positions. In this paper, we propose a mobile user mobility model considering office-going/closing and office hours for evaluating the effect of user mobility on the performance of mobile networks. We analyze the transient characteristics of a mobile network in terms of the mean location update rate.