Ntt Mobile Communications Network, Inc.

Shigehide Sawayanagi

Kazufumi Yunoki

Hidetoshi Yazaki

Kouji Chiba

Norihito Tokuhiro

A control channel is searched for call waiting in a mobile station where the power supply for a receiving circuit is turned off during a break time of receiving level measurements, wherein in a first control channel selection mode, all the control channels are divided into a plurality of groups, the receiving levels of the control channels are measured group by group intermittently and sequentially. The intermittent measurement of these groups are repeated until a control channel having a receiving level equal to or greater than a first predetermined value is detected. When a receiving level equal to or greater than the first predetermined value is detected, the receiving levels of all the control channels are measured in a second control channel selection mode.

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Yokosuka, Japan

Shigehide Sawayanagi