COMMUNICATION SYSTEM

PROBLEM TO BE SOLVED: To provide a communication system which is capable of alleviating troubles annoying a user when a mobile communication device is moved through a tunnel or a mountainous area where communication conditions get worse. SOLUTION: The communication system is equipped with a mobile telephone 130 establishing radio communication; a position detector 133a detecting the position of the mobile telephone 130; a communication state storing unit 117 storing communication state data 117a indicating a communication level at positions; a prediction unit 114 estimating the position of the mobile telephone 130 a prescribed time later on the basis of the position detected by the position detector 133a, and predicting a radio communication state at the position, referring to the communication state data 117a; and a prediction processing unit 115 taking countermeasures against the interruption of communication between the mobile telephone 130 and one of telephones 140a to 140c due to the degradation of a radio communication state on the basis of a prediction result obtained from the prediction unit 114. COPYRIGHT: (C)2004,JPO&NCIPI