Method and apparatus for transmitting and receiving duplicate packets in next-generation mobile communication system
A communication method and system for converging a 5 th -Generation (5G) communication system for supporting higher data rates beyond a 4 th -Generation (4G) system with a technology for Internet of Things (IoT) is provided. The method includes intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The disclosure provides a packet processing method of a transmitter that include transmitting a radio link control (RLC) service data unit (SDU) to a receiver; receiving, from the receiver, a first message including information about whether the RLC SDU is successfully transmitted; and transmitting a first indicator indicating successful transmission of the RLC SDU from an RLC entity of the transmitter to a packet data convergence protocol (PDCP) entity of the transmitter when the receiver receives the RLC SDU.
1. A packet processing method of a transmitting device including a packet data convergence protocol (PDCP) entity, a first radio link control (RLC) entity, a second RLC entity, and a medium access control (MAC) entity in a wireless communication system, the method comprising:
delivering, by the PDCP entity to the first RLC entity, a first PDCP protocol data unit (PDU) to be transmitted to a receiving device;
delivering, by the PDCP entity to the second RLC entity, a second PDCP PDU to be transmitted to the receiving device, the first PDCP PDU and the second PDCP PDU being associated with a packet duplication;
obtaining, by the PDCP entity from the first RLC entity which has received a positive acknowledge associated with the first PDCP PDU transmitted to the receiving device, first information indicating successful delivery of the first PDCP PDU; and
delivering, by the PDCP entity to the second RLC entity, second information indicating a discard of the second PDCP PDU based on the first information,
wherein a RLC service data unit (SDU) corresponding to the second PDCP PDU is discarded based on the second information, by the second RLC entity, in case that at least one RLC PDU from the RLC SDU corresponding to the second PDCP PDU has been generated, and neither the RLC SDU nor a segment thereof has been delivered from the second RLC entity to the MAC entity.
2. The method of claim 1 , further comprising:
obtaining, by the PDCP entity from the second RLC entity which has received a positive acknowledge associated with the second PDCP PDU transmitted to the receiving device, third information indicating successful delivery of the second PDCP PDU, in case that a negative acknowledge associated with the first PDCP PDU is received after delivering the first PDCP PDU to the first RLC entity; and
delivering, by the PDCP entity to the first RLC entity, fourth information indicating a discard of the first PDCP PDU based on the third information,
wherein a RLC SDU corresponding to the first PDCP PDU is discarded based on the fourth information, by the first RLC entity, in case that at least one RLC PDU from the RLC SDU corresponding to the first PDCP PDU has been generated, and neither the RLC SDU nor a segment thereof has been delivered from the first RLC entity to the MAC entity.
3. The method of claim 2 ,
wherein a first RLC PDU is generated, by the first RLC entity, using a third PDCP PDU based on an RLC sequence number associated with the first RLC SDU indicated as not received by the receiving device, in case that the positive acknowledge for the second PDCP PDU is received, and
wherein the generated first RLC PDU is transmitted to the receiving device through the first RLC entity.
4. The method of claim 1 ,
wherein a mapping table associated with a transmission of the first PDCP PDU or the second PDCP PDU is updated.
5. A transmitting device including a packet data convergence protocol (PDCP) entity, a first radio link control (RLC) entity, a second RLC entity, and a medium access control (MAC) entity in a wireless communication system, the transmitting device configured to:
deliver, by the PDCP entity to the first RLC entity, a first PDCP protocol data unit (PDU) to be transmitted to a receiving device,
deliver, by the PDCP entity to the second RLC entity, a second PDCP PDU to be transmitted to the receiving device, the first PDCP PDU and the second PDCP PDU being associated with a packet duplication,
obtain, by the PDCP entity from the first RLC entity which has received a positive acknowledge associated with the first PDCP PDU transmitted to the receiving device, first information indicating successful delivery of the first PDCP PDU, and
deliver, by the PDCP entity to the second RLC entity, second information indicating a discard of the second PDCP PDU based on the first information,
wherein a RLC service data unit (SDU) corresponding to the second PDCP PDU is discarded based on the second information, by the second RLC entity, in case that at least one RLC PDU from the RLC SDU corresponding to the second PDCP PDU has been generated, and neither the RLC SDU nor a segment thereof has been delivered from the second RLC entity to the MAC entity.
6. The transmitting device of claim 5 , further configured to:
obtain, by the PDCP entity from the second RLC entity which has received a positive acknowledge associated with the second PDCP PDU transmitted to the receiving device, third information indicating successful delivery of the second PDCP PDU, in case that a negative acknowledge associated with the first PDCP PDU is received after delivering the first PDCP PDU to the first RLC entity, and
deliver, by the PDCP entity to the first RLC entity, fourth information indicating a discard of the first PDCP PDU based on the third information,
wherein a RLC SDU corresponding to the first PDCP PDU is discarded based on the fourth information, by the first RLC entity, in case that at least one RLC PDU from the RLC SDU corresponding to the first PDCP PDU has been generated, and neither the RLC SDU nor a segment thereof has been delivered from the first RLC entity to the MAC entity.
7. The transmitting device of claim 6 ,
wherein a first RLC PDU is generated, by the first RLC entity, using a third PDCP PDU based on an RLC sequence number associated with the first PDCP PDU indicated as not received by the receiving device, in case that the positive acknowledge for the second PDCP PDU is received, and
wherein the generated first RLC PDU is transmitted to the receiving device through the first RLC entity.
8. The transmitting device of claim 5 ,
wherein a mapping table associated with a transmission of the first PDCP PDU or the second PDCP PDU is updated.
9. The method of claim 2 ,
wherein a first RLC PDU is generated, by the first RLC entity, based on an RLC sequence number associated with the first PDCP PDU indicated as not received by the receiving device and the first PDCP PDU indicated as not received by the receiving device in case that the positive acknowledge for the second RLC SDU is received, and
wherein the generated first RLC PDU is transmitted to the receiving device, through the first RLC entity.
10. The transmitting device of claim 6 ,
wherein a first RLC PDU is generated, by the first RLC entity, based on an RLC sequence number associated with the first PDCP PDU indicated as not received by the receiving device and the first PDCP PDU indicated as not received by the receiving device in case that the positive acknowledge for the second RLC SDU is received, and
wherein the generated first RLC PDU is transmitted to the receiving device, through the first RLC entity.