在這篇文章，我們提出一個同步(Concurrent)且有效率的新方法來搜尋用戶，我們主要是利用用戶移動時如果有相關性，我們利用這個相關性來幫我們達到預測用戶的位置。以前的相關文獻大部分著重在討論只搜尋一個用戶，或者用戶移動上互相獨立。我們定義一個新的相關用戶移動模型，使得統計上用戶們在移動方向與位置上相關。並在這篇論文中，我們提出一個新的方法去找到用戶之間的相關性，而不用去推導複雜的數學位置分佈模型及證明。從模擬中可看出，只要相關程度到達某個程度，使用相關用戶幫我們搜尋，可以更快找到用戶，減少用戶等待時間，並增加系統所能容納的最大容量。

In this paper, we propose the correlated concurrent search approach to simultaneously and efficiently locate the mobile stations in the communications networks. Previous work either focuses on locating a single mobile user or assumes that the locations of mobile users are statistically independent. We first propose a mobility model in which the movements of mobile stations are statistically correlated. Next, we propose a new approach to discover the correlations among the mobile stations without calculating their joint location probability distribution function. Our simulation results show that as long as the correlation coefficient is larger than to a specific value, the location correlation could be used to reduce the average paging delay and increase the maximum stable throughput.

Abstract ……………………………………………………………………………i
Contents …………………………………………………………………………iii
Lists of Figures ……………………………………………………………… iv
1.Introduction…………………………………………………………1
1.1 Background of the 3G Communication Networks……1
1.2 Mobility Management (MM)……………………4
1.3 Location Update and Paging Mechanisms…………………… 5
1.4 Previewing Papers about the Location Update and Paging Mechanisms…5
2. A Novel Mobility Model for Correlated Users……………………………7
2.1 Problem Formulation of the Mobility Management………………………7
2.2 Mathematical Model……………………………………………8
3. A Novel Algorithm ……………………………………………12
3.1 Lists and Queues in the Control Center ………………12
3.2 A New Call Created………………………………………12
3.3 How to Find the Correlated Mobile User of the Called Mobile User……13
3.4 Priority ……………………………………………………16
3.5 Maximum Delay Time……………………………………………18
3.6 The Complete Algorithm……………………………………18
4. Simulation …………………………………………………20
4.1 Simulation Methods ………………………………………… 20
4.2 Simulation Results……………………………………… 21
5. Conclusions……………………………………………………… 32
Reference…………………………………………………………33

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