A terminal apparatus detects a downlink frame timing based on a synchronization signal in EUTRAN, receives a TA (Timing Advance) command from a base station apparatus of the EUTRAN, transmits an uplink signal in the EUTRAN to the base station apparatus of the EUTRAN at a timing based on at least the downlink frame timing and a value of the TA command, and transmits a signal between terminal apparatuses to another terminal apparatus at the same timing.