Patent ID: 6965570

Claim:
A communication controller which selects one out of a plurality of radio communication lines and performs communication using the selected line, said communication controller comprising: a slot to which one of a plurality of connection units is connected, the connection units being connected to each one of said radio communication lines; a radio-field-intensity acquisition unit which acquires a radio field intensity of each of said radio communication lines; a selection unit which selects one of said connection units whose radio field intensity is equal to or higher than a threshold; a control unit which provides a control to perform data communication using said connection unit selected by the selection unit and said radio communication line corresponding to said selected connection unit; and a mounted-state monitoring unit which monitors a connection state of said connection units, wherein, based on the result of monitoring the connection state of said connection units by said mounted-state monitoring unit, said control unit provides said control to perform data communication using said selected connection unit only when said selected connection unit is connected, and said control unit waits until reconnection is designated when data transmission or reception is interrupted because of an error, and continues said data communication starting with unsent data next to the sent data before the interruption, after the reconnection.