An Enhanced Direction-based Location Update Scheme for PCS networks

Future personal communication service (PCS) networks consider smaller cells to accommodate continuously growing population of subscribers. Frequently performed location updates caused by such an infrastructure incur extensive signaling and consequently higher cost. Thus, new strategies are demanded to locate mobile users more efficiently. Among several proposals, the direction-based location update (DBLU) scheme uses a dynamic strategy such that the mobile users update their locations only when a change of direction occurs. To locate users, the system pages cells along the direction of initial move. The scheme works well when the change of direction is infrequent and the ratio of location update cost to paging cost is low. Otherwise, the location update, and consequently the overall cost increase significantly. To attack this problem, we propose an enhanced direction-based location update (EDBLU) scheme, which takes into account both the moving distance and the moving direction. We analyze the performance of the EDBLU under different mobility patterns and call-to-mobility ratios based on a 2D Markov walk model. The numerical results demonstrate that the proposed scheme augments the performance reported by the distance-based and the direction-based methods