Modified group method for mobility management

Abstract

The Group Method as identified in IS-41 standard was modified in this study to be dual group system to identify the optimal group size and to cope with the location tracking problem of the wireless system. The Group Method can effectively reduce the loading of the network caused by tracking mobile users in a mobile cellular system because it joins several cells to form a group. Instead of performing registration and deregistration for each individual in cell, the Group Method performs these tasks on a group scale. Moreover, the Dual Group Method saves network resources because it eliminates unnecessary location updates due to its fewer group boundary passes. This study also evaluates the cost ratios between the Basic Method and the Group Method. The effectiveness of this scheme is illustrated in the following two examples. First, the Group Method offers a saving about 40% of network resources (a reducing rate of 0.589) when the Call-to-Mobility Ratio (CMR) (R. Jain, Y.-B. Lin, C. Lo, S. Mohan, Proc. INFOCOM’95, (1995) 481–489; IEEE J. Select. Areas Commun., 12(8), (1994)), and the cost of message transmission/cost of database transaction (TDCR) is equal to 0.2. Second, about 15% of system resources are saved (a reducing rate is 0.847); when the CMR is equal to 0.5 and the TDCR is equal to 0.4. Results in this study demonstrate that the Group Method yields significant benefits in terms of reducing rate and that the Dual Group system is more beneficial.