An Adaptive Direction-Based Location Update Scheme for Next Generation PCS Networks

1 The work described in this paper was partially supported by a strategic grant from the City University of Hong Kong [Project No. CityU 7001259]. Abstract. This paper studies the location management problem in PCS network. An adaptive direction-based location update (ADBU) scheme is proposed in which a line-paging method is adopted to minimize the paging cost and an adaptive direction-based scheme is formulated for location update generation. Mobile terminals inspect their directions and a location update will be generated when the change in the direction of a mobile terminal is greater than the direction threshold. In the paper, we assume that the movement of a mobile terminal in a period of time can be divided into steps and each step has a destination. Then, we use a Gauss-Markov process to model the movement of a mobile terminal in each step. With the Gauss-Markov model and a feedback control mechanism, we estimate the optimal value for the direction threshold with the attempt to minimize the update cost and at the same time limit the paging cost using line-paging. Performance results have shown that the performance of ADBU is significantly better than another direction-based update scheme and the distance-based scheme a result of smaller paging cost and update processing cost.