Method for changing over to different frequency at cellular phone system and cellular phone system using the method and base station controlling apparatus in the system and mobile communication terminal in the system

摘要

A method for changing over to different frequency in a cellular phone system, in which lowering the probability generating a call drop and decreasing the power consumption when the moving velocity of a mobile communication terminal connecting a micro-cell becomes high can be realized. A judging threshold value Th_HO using at the changing over to the different frequency is changed corresponding to the moving velocity of the mobile communication terminal. When the moving velocity of the mobile communication terminal connecting to a micro-cell becomes high, the judging threshold value Th_HO is changed to be a small value, and the probability changing over to the different frequency is made to be high, and it makes easy for the mobile communication terminal to connect to a macro-cell. With this, the probability generating the call drop can be decreased.