Abstract: A wireless mobile terminal device including: a position data detector that detects position data; a wireless communication system type data detector that detects wireless communication system type data or relation data; a memory that accumulates the position data and the wireless communication system type data or the relation data in association with each other; a memory controller that autonomously and sequentially stores the position data and the wireless communication system type data or the relation data into the memory; and a wireless communication system type data retriever that selects, upon receipt of current position data, wireless communication system type data of the current position or relation data through adaptive retrieval of a plurality of pieces of the position data and the wireless communication system type data or the relation data in association with each other. This configuration efficiently selects a wireless communication system.

Abstract: If an outgoing call is generated, a control unit discriminates on the basis of various tables stored in a memory unit whether or not a system waiting for incoming calls is set with top priority in PRL, whether or not the outgoing call is an outgoing call of a preset type, whether or not the system is roaming, whether or not the system waiting for incoming calls is a system set to execute re-selection, whether or not the outgoing call is an outgoing call for which a system of higher priority is set, and re-selects the system employed for outgoing call if necessary. In addition, at the re-selection, the control unit limits the time for re-searching of the standby systems and the number of the searched systems in accordance with the outgoing call type.

Abstract: In a first standby state, the reception quality of a signal from a system which has established synchronization is detected. If the detected reception quality deteriorates to be less than a threshold value, the destination of synchronization establishment is changed from a first system to a second system. In a second standby state after this system change, the reception quality of a system having a higher priority order of selection than the second system which has established synchronization is detected. If a third system whose detected reception quality exceeds the threshold value is found, the destination of synchronization establishment is changed to this third system again. After that, the first standby state is returned.

Abstract: A communication system in which a calling party mobile station is capable of automatically obtaining information on a plurality of currently available communication modes of a called party mobile station and charge rate information to enable a user of the calling party mobile station to determine which mode is to be used for communication with the called party mobile station based on the information thus obtained. The called party mobile station notifies information on currently available communication modes to a circuit switching station. The circuit switching station stores position information and communication mode information of the called party mobile station, and obtains information on the service provider and so on of the called party mobile station from another switching station. The calling party mobile station places a call for the called party mobile station, to the circuit switching station.

Abstract: In a first standby state, the reception quality of a signal from a system which has established synchronization is detected. If the detected reception quality deteriorates to be less than a threshold value, the destination of synchronization establishment is changed from a first system to a second system. In a second standby state after this system change, the reception quality of a system having a higher priority order of selection than the second system which has established synchronization is detected. If a third system whose detected reception quality exceeds the threshold value is found, the destination of synchronization establishment is changed to this third system again. After that, the first standby state is returned.

Abstract: In a first standby state, the reception quality of a signal from a system which has established synchronization is detected. If the detected reception quality deteriorates to be less than a threshold value, the destination of synchronization establishment is changed from a first system to a second system. In a second standby state after this system change, the reception quality of a system having a higher priority order of selection than the second system which has established synchronization is detected. If a third system whose detected reception quality exceeds the threshold value is found, the destination of synchronization establishment is changed to this third system again. After that, the first standby state is returned.

Abstract: A system selection mode resetting function is newly added as a system selection mode to a mobile communication terminal apparatus having a plurality of system selection modes assigned different priorities. A system selection mode setting unit checks a system selection mode stored in the first memory in response to power-off or subsequent power-on. If the determination result reveals the presence of another mode higher in priority than the mode stored in the first memory, the mode stored in the first memory is reset to the higher-priority mode.

Abstract: A system selection mode resetting function is newly added as a system selection mode to a mobile communication terminal apparatus having a plurality of system selection modes assigned different priorities. A system selection mode setting unit checks a system selection mode stored in the first memory in response to power-off or subsequent power-on. If the determination result reveals the presence of another mode higher in priority than the mode stored in the first memory, the mode stored in the first memory is reset to the higher-priority mode.

Abstract: In a first standby state, the reception quality of a signal from a system which has established synchronization is detected. If the detected reception quality deteriorates to be less than a threshold value, the destination of synchronization establishment is changed from a first system to a second system. In a second standby state after this system change, the reception quality of a system having a higher priority order of selection than the second system which has established synchronization is detected. If a third system whose detected reception quality exceeds the threshold value is found, the destination of synchronization establishment is changed to this third system again. After that, the first standby state is returned.