Distance-based location update scheme with isotropic random user motion with drift

Location tracking in wireless networks is essential for ubiquitous communication service. Since a user may move freely, the network has to keep track of the location of the mobile terminal to deliver messages or calls. There has been significant effort to address the problem of user mobility; however, most of the mobility models introduced in the previous work do not take the movement direction into account - the parameter called CMR (call to mobility ratio) which is commonly used in the literature is the ratio between the call arrival rate and the cell boundary crossing rate of the mobile. In this paper, we introduce Brownian motion with drift as our mobility model and discuss the effect of movement direction and call arrivals on the performance of the distance-based location update scheme in the predictive and the non predictive mode.