小区分层依概率寻呼的位置管理策略

A location Management Strategy with Layered Cells and Terminal Paging in Probability Order

位置管理是移动通信领域的一个具有挑战性的问题 ,涉及到位置更新和位置查找操作 .我国及其他国家目前正在使用的个人通信网络中 ,基本的位置管理策略 (简称“基本策略”)的位置查找操作采用的是 ,在整个位置区中同步寻呼移动台 .由于所要寻找的移动台只在由众多小区所组成的位置区内的一个小区中 ,因此 ,“基本策略”会造成系统资源的极大浪费 .本文给出一种对位置区内的小区进行分层 ,按移动台在各层小区的概率从大到小的次序 ,逐层进行寻呼的位置管理策略 (简称“分层策略”) .在假定移动台在各个小区的逗留时间是符合一般概率分布的随机变量的条件下 ,推导出移动台处于各层小区的概率及“分层策略”所需搜索的小区平均个数公式 .证明了“分层策略”的位置管理费用不大于“基本策略”

Location management,which consists of location updating and location query,is a challenging topic in mobile communication.The location query of the basic location management scheme (Basic Scheme for short) used in personal communications services (PCS) networks in many countries, requires to page a mobile in all the cells within a location area (LA) simultaneously.This scheme is likely to waste the system's channel resource and processing resource enormously,since the LA consists of many cells whereas the mobile only resides in one.This paper proposed a new location management scheme,Cell Layered Scheme,which grouped all the cells of each LA into layers and made terminal paging one layer after another in probability order.Both the probability of the mobile residing in each layer and the average number of cells searched by the proposed scheme are derived on the assumption that the residence time of a mobile residing in each cell is a generally distributed random variable.It is proved that the cost of the Cell Layered Scheme is no more than that of the Basic Scheme.