Method and apparatus for performing cell on/off operation in wireless communication system

An evolved NodeB (eNB) which operates in LTE in an unlicensed (LTE-U) spectrum, the eNB comprising:

• a memory;
• a transceiver;
• and
• a processor, operatively coupled to the memory and the transceiver, wherein the processor is configured to:
• configure a periodic transmission of a discovery reference signal (DRS) with DRS occasion:
• start carrier sensing on a channel related to a wireless local area network (WLAN), before the DRS occasion by an amount of time equal to a maximum allowed channel occupancy time of the WLAN;
• detect when the channel is idle;
• occupy the channel immediately after the channel becomes idle;
• control the transceiver to transmit a reservation signal until the DRS occasion;
• and
• control the transceiver to transmit DRS in the DRS occasion,
• wherein a periodicity of the DRS occasion is longer than the maximum allowed channel occupancy time.