To provide a telephone system capable of remote and accurate cause analysis.

In a communication system 1 including a radio set 20, a base station device 30, and a network managing device 40; the radio set 20 stores acquiring operation description data specifying communication quality information of at least an object of acquisition, acquires communication quality information regarding the radio set 20 according to the acquiring operation description data, and further transmits the acquired communication quality information to the network managing device 40 which updates the acquiring operation description data that the radio set 20 stores; and the radio set 20 acquires communication quality information regarding the radio set 20 according to the updated acquiring operation description data.