Method and apparatus for efficient packet duplication transmission in mobile communication system

A terminal in a communication system, the terminal comprising:

• a transceiver;
• and
• at least one processor coupled with the transceiver and configured to:
• receive, from a base station, a radio resource control (RRC) message including configuration information, the configuration information including information associated with a packet duplication and information on at least two logical channels,
• duplicate uplink packets in case that the packet duplication is activated,
• transmit, to the base station, the duplicated uplink packets on a first logical channel and a second logical channel based on the information on the at least two logical channels, the first logical channel and the second logical channel being included in the at least two logical channels,
• receive, from the base station, a first downlink packet on the first logical channel, and
• receive, from the base station, a second downlink packet on the second logical channel,
• wherein the first downlink packet is different from the second downlink packet,
• wherein the uplink packets are pre-processed before receiving an uplink grant including resource allocation information, and
• wherein radio link control (RLC) sequences associated with the uplink packets are allocated to the uplink packets after receiving the uplink grant.