Apparatus and method for communicating

A method of operating a user equipment (UE) in a wireless communication system, comprising:

• transmitting and receiving signals, in a second communication mode, to and from a base station through a first communication unit including a transmitter which transmits a first signal to the base station or another UE and a first receiver which receives a second signal from the base station;
• and
• transmitting a signal, in a first communication mode, to the another UE through the first communication unit or receiving a signal from the another UE through a second communication unit including a second receiver which receives a third signal from the another UE and a third receiver which receives a fourth signal from the base station.

A transceiver chip set, comprising a chip set configured to:

• transmit and receive signals, in a second communication mode, to and from a base station through a first communication unit including a transmitter which transmits a first signal to the base station or another UE and a first receiver which receives a second signal from the base station;
• and
• transmit a signal, in a first communication mode, to the another UE through the first communication unit or receive a signal from the another UE through a second communication unit including a second receiver which receives a third signal from the another UE and a third receiver which receives a fourth signal from the base station.