Radio communication apparatus and radio communication method

A radio communication method used in a radio communication apparatus that operates with a battery and that includes a network connection unit which allows the radio communication apparatus to connect to a plurality of radio communication networks using a radio signal, the radio communication method comprising the steps of:

• controlling a handover by said radio communication apparatus from a currently-connected radio communication network to one of other radio communication networks;
• detecting an output voltage outputted by the battery;
• acquiring a voltage drop value that would occur as the network connection unit is to be connected to the one of the radio communication networks used in the ongoing handover;
• obtaining a predicted voltage by subtracting the voltage drop value that would occur from the current output voltage;
• and
• comparing the predicted voltage against a predetermined threshold and detecting whether the predicted voltage is no more than said threshold;
• and stopping execution of the handover to the other radio communication network upon detecting that the predicted voltage obtained is not more than a predetermined threshold.

A radio communication apparatus that operates with a battery and is connectable to a plurality of radio communication networks, the radio communication apparatus comprising:

• a voltage detector configured to detect an output voltage outputted by the battery;
• and a storage unit configured to store, for each of the radio communication networks,
• a battery voltage drop table indicating a voltage drop value that would occur in a case where the radio communication apparatus is to be connected to any one of the radio communication networks other than a currently connected network,
• a determination unit configured to obtain a predicted voltage by subtracting the voltage drop value that would occur from the current output voltage, based on which to determine whether or not to execute a handover from a currently-connected radio communication network to other radio communication network;
• a handover controller configured to determine whether the predicted voltage is more than a predetermined threshold on the basis of the determination result of the determination unit, execute a handover from currently-connected radio communication network to other radio communication network when the predicted voltage is more than a predetermined threshold, and to stop execution of the handover from currently-connected radio communication network to other radio communication network when the predicted voltage is not more than the predetermined threshold.