无线网络基于距离的位置管理建模和开销分析

针对无线网络如何精确计算位置管理开销这一问题，采用嵌入式马尔科夫链作为移动模型描述移动终端在二维蜂窝网络的运动，通过建立两个连续呼叫间隔内位置更新的模型分析呼叫到达和小区驻留时间均为一般分布时基于距离的位置管理方案的位置更新次数和位置管理总开销，对无线网络进行性能评估。通过分析得到如下结论：（1）位置更新次数是距离闽值的减函数；（2）位置管理开销是距离阂值的凸函数；（3）当所选取的距离阈值较小时，位置更新开销影响位置管理开销较大；当所选取距离阈值较大时，寻呼开销影响位置管理开销较大。通过仿真分析验证了理论分析的正确性。

Modeling and Cost Analysis of Distance-based Location Management in Wireless Communication Networks

Location management is of great importance in wireless communication networks,which mainly aims at effectively keeping track of mobile terminals(MTs) for call delivery.Performance analysis plays a central role in the implementation of location management methods and system design in wireless communication networks,in which,the signaling cost analysis is an essential performance index.Three dynamic location management schemes,such as time-based,movement-based and distance-based location management schemes were developed to improve the performance of wireless communication networks.Among these schemes,the distance-based location management scheme is of the lowest cost.However,the current cost analysis are simple but not applicable to the actual network framework.One reason is the complexity and difficulty of the issue.This paper put forwards embedding Markov chain as mobility model to describe the movement of MT in Two-dimensional cellular structures.We established the location update model between two consecutive arrival calls.Both inter-call time and cell residence time have arbitrary distributions.Based on the above,we get the formula of number of location update and location management cost.The performance of dynamic distance-based location management scheme in wireless networks was analyzed.Our analysis makes it possible to find the optimal distance threshold that minimizes the total cost of location management in a distance-based location management scheme.