MOBILE COMMUNICATION SYSTEM AND USER TERMINAL

摘要

In a mobile communication system that supports D2D communication in which radio communication is directly performed between a first user terminal and a second user terminal in a frequency and a time assigned from a base station, in a time in which data is to be received from the first user terminal, when the second user terminal does not receive the data from the first user terminal, the second user terminal transmits failure notification indicating reception failure in the D2D communication to the base station.