Method and apparatus for performing efficient layer 2 function in mobile communication system

A method performed by a receiver in a communication system, the method comprising:

• receiving, by a medium access control (MAC) entity of the receiver, a MAC protocol data unit (PDU) from a lower layer;
• identifying, by the MAC entity, a MAC service data unit (SDU) and a MAC subheader based on the MAC PDU;
• and
• delivering, by the MAC entity, the MAC SDU,
• wherein the MAC subheader corresponds to the MAC SDU,
• wherein the MAC subheader to which the MAC SDU corresponds is placed immediately in front of the MAC SDU, and
• wherein the MAC subheader to which the MAC SDU corresponds does not include an E field indicating whether another MAC subheader, MAC control element (CE), or MAC SDU follows.

A transmitter in a communication system, the transmitter comprising:

• a transceiver;
• and
• a controller coupled with the transceiver and configured to:
• obtain, by a medium access control (MAC) entity of the transmitter, a MAC service data unit (SDU),
• generate, by the MAC entity, a MAC protocol data unit (PDU) including a MAC subheader and the MAC SDU, and
• send, by the MAC entity, the MAC PDU to a lower layer,
• wherein the MAC subheader corresponds to the MAC SDU,
• wherein the MAC subheader to which the MAC SDU corresponds is placed immediately in front of the MAC SDU, and
• wherein the MAC subheader to which the MAC SDU corresponds does not include an E field indicating whether another MAC subheader, MAC control element (CE), or MAC SDU follows.

A receiver in a communication system, the receiver comprising:

• a transceiver;
• and
• a controller coupled with the transceiver and configured to:
• receive, by a medium access control (MAC) entity of the receiver, a MAC protocol data unit (PDU) from a lower layer,
• identify, by the MAC entity, a MAC service data unit (SDU) and a MAC subheader based on the MAC PDU, and
• deliver, by the MAC entity, the MAC SDU,
• wherein the MAC subheader corresponds to the MAC SDU,
• wherein the MAC subheader to which the MAC SDU corresponds is placed immediately in front of the MAC SDU, and
• wherein the MAC subheader to which the MAC SDU corresponds does not include an E field indicating whether another MAC subheader, MAC control element (CE), or MAC SDU follows.