Jang Hyun Baek

Modeling and optimization of zone-based registration considering cell-by-cell location area for mobile communication networks

Zone-based registration (ZBR) has been adopted in most mobile communication networks and there have been numerous analytical models and performance studies of ZBR. However, many previous studies in which ZBR was compared with other registration schemes utilized ring-by-ring location registration area and two-dimensional random walk mobility models. In this study we show that this approach fails to smoothly reflect ZBRs actual operation. As an alternative, we propose a new analytical model that can accurately reflect ZBRs real operation in regard to the shape of a location area and mobility of the mobile stations, to find the optimal size of proposed cell-by-cell location registration area. We provide numerical results using the proposed approach to properly optimize the performance of ZBR under various circumstances. The results demonstrate that the number of cells in a location registration area that minimizes total cost is 2-4, and this approach is more accurate than the previous ring-by-ring location area. The results of this study should be useful for others analyzing the performance of various mobile communication registration systems.

Performance analysis and optimization of an improved dynamic movement-based location update scheme in mobile cellular networks

In this study, we propose an improved version of the dynamic movement-based location update scheme that stores all cells visited by the MS, and their neighboring cells, to reduce the location update cost of the dynamic movement-based location update scheme. We show that a significant reduction in the location update cost is achieved in our scheme. We also show that our scheme has optimal total cost when the threshold is rather small. Additionally, the MS requires a minimal amount of memory to successfully implement our scheme.

MODELING AND OPTIMIZATION OF ZONE-BASED REGISTRATION FOR MOBILE COMMUNICATION NETWORK

An efficient mobility management for mobile stations plays an important role in mobile communication networks. Two basic operations of mobility management are location registration and paging. A zone-based registration (ZBR) is implemented in most of the mobile communication networks and we consider the mobility management scheme that combines a zone-based registration and a selective paging (SP). We propose a new analytical model that can reflect the characteristics of the ZBR smoothly where location areas of the ZBR are set up so that regions such as roads, bridges, rivers and mountains, where there is relatively little traffic, will constitute their boundaries. We adopt a revised 2-dimensional random walk mobility model to consider such characteristics. In addition, we propose a more efficient division scheme of location area for 2-step selective paging. We evaluate the performance of the mobility management scheme using our mobility model to determine the optimal size of a location area that will result in the minimum signaling traffic on radio channels. Numerical results are provided to demonstrate that our mobility model is useful to evaluate the ZBR more exactly. The results of this study can be used effectively in analyzing and comparing the performances of various mobility management schemes.

Performance evaluation and comparison of two random walk models in the PCS network

In this paper, we evaluate the performance of the MBR (movement–based registration) scheme using a modified one-dimensional random walk model and a two–dimensional random walk model to compare the accuracy of two random walk models The difference between these two models is identified and the performance difference in a mathematical approach is presented to support it Analytical results are provided to demonstrate that the modified one–dimensional random walk always overestimates the performance of the MBR and that the two–dimensional random walk model should be used to obtain the exact performance of the MBR, and other registration schemes.