Radio-link continuity keeping equipment in cellular telephone mobile

Abstract

A radio-link continuity keeping equipment in a cellular telephone mobile station includes a removable battery, a backup memory for storing therein a channel connection information when the battery is removed during a conversation mode, a timer for measuring an elapsed time after the battery is removed during the conversation mode until the battery is again set, and a device for judging whether or not the elapsed time measured by the timer is within a predetermined time and when the elapsed time is within the predetermined time, for restoring voice channel on the basis of the channel connection information stored in the backup memory. The timer is provided for measuring a time during which a battery is detached, i.e., the elapsed time after the battery is detached until a new battery is again set. When the measured time of the timer is shorter than the predetermined time, a voice channel is restored on the basis of the channel connection information stored in the backup memory. As a result, when the user exchanges the old battery with a new one in the predetermined time, a radio-link continuity can easily be kept.