A mobile communication method in which a radio terminal connects to a network so as to perform a communication, comprises: a step in which the radio terminal detects an occurrence of a connection failure with the network in a connected state; and a step of sending a radio link failure (RLF) report regarding the detected connection failure, from the radio terminal to the network. In the step of sending the RLF report, the radio terminal sends time information, which is contained in the RLF report, for identifying a time of occurrence of the connection failure, to the network.