Base Station Apparatus and Mobile Communication System

Abstract

Disclosed is a handover method in radio communication. A base station apparatus monitors the receiving state of a terminal, detects, based upon the receiving state, whether the terminal is one in which there is a possibility that loss of a call or a decline in quality will occur or one in which loss of a call or a decline in quality has occurred, and hands over the terminal to another base station apparatus having a carrier frequency different from that of the present base station apparatus.

1 . A mobile communication method in a mobile communication system having a terminal, a base station apparatus for wirelessly communicating with the terminal, and a upper layer controller for controlling the base station apparatus, comprising:
 at a present base station apparatus,   monitoring transmission speed of each terminal;   detecting, based upon the transmission speed, a terminal in which there is a possibility that loss of a call or a decline in quality will occur; and   requesting a upper layer controller to hand over said detected terminal to another base station apparatus; and   at the radio network controller, handing over said terminal from the present base station apparatus to another base station apparatus which has a carrier frequency different from that of the present base station apparatus, in response to said request, wherein   said terminal hands over from the present base station apparatus to the another base station apparatus.