在日本个人手持电话系统（ＰＨＳ）中，便携机必须支持信道从一个小区（Ｚｏｎｅ）切换到另一小区的操作。这中间涉及两个重要的处理：检测移出服务区的信道和决定新的小区。本文描述这两种处理，其一是信道移出小区的判断准则──通信质量，此评估的结果取决于所使用的算法和检测间隔；其二是比较便携机在预定周期内所接收的所有基站控制信道的接收电平值，并从中选择相应的基站。 In Japan’s Personal Handyphone System (PHS), laptops must support channel switching from one zone to another. There are two important processes involved in this interim: detecting the channel moving out of the service area and deciding the new cell. This article describes both of these processes, one of which is the decision criteria for the channel to move out of the cell - the quality of the communication, the result of which depends on the algorithm and detection interval used; the second is to compare all base stations received by the portable in a predetermined period Control channel receive level value, and select the appropriate base station.