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Although a lot of works for location management in wireless networks have been reported in the literature, most of the works have been focused on designing per-user-based strategies. This means that they can achieve the performance enhancement only for a certain class of mobile users with a specific range of CMR (call-to-mobility ratio). However, these per-user-based strategies can actually degrade the performance if a user's CMR changes significantly. Therefore, an efficient uniform location management strategy, which can be commonly applied to all mobile users regardless of their CMR, is proposed and analyzed in this paper. The motivation behind the proposed strategy is to exploit the concepts of the two well-known existing strategies: the location caching strategy and the local anchor strategy. That is, the location caching strategy exploits locality in a user's calling pattern, whereas the local anchor strategy exploits locality in a user's mobility pattern. By exploiting these characteristics of both strategies together with the profile management at the HLR (home location register), the proposed strategy can reduce the frequent access to the HLR, and thus effectively results in significant reduction in terms of the total location management cost. The analytical results also demonstrate that the proposed strategy can be uniformly applied to all mobile users, while always maintaining the performance gain over the IS-41 standard regardless of a user's CMR and the network traffic conditions.
The second generation of mobile communications is growing rapidly to the third generation due to various communication techniques and the increasing number of users. PCS, the communication method of the third generation, should be able to provide users with various services, independently of the current location. To PCS, the mobility management of users is essential. The mobility management method which has been used has a structural drawback: as the number of users increase, HLR becomes the bottleneck. Everyone is expected to have one terminal in the third generation mobile communications age. Therefore, an enhanced mobility management scheme to reduce the bottleneck of the HLR, should be used in the third generation mobile communications. In this paper, we propose a new mobility management method where the trace of terminals is left in the VLRs, so that a call can be connected by querying only to the VLRs rather than to the HLR when the terminal-terminated-call occurs. The proposed method distributes messages to VLRs and effectively reduce mobility management cost. To estimate overall mobility management cost, we simulated the new method of PCS network. The simulation model is based on the Jackson's network, and makes it possible to estimate mobility management cost of PCS networks. IS-41 and proposed scheme are compared based on the computer simulation. Considering the delay times both in HLR and VLR, and considering both location registration cost and call delivery cost, the proposed modeling method shows the improvement.