Network coding termination and procedures using feedback
Certain aspects of the present disclosure provide techniques for efficiently terminating wireless transmissions of network coded packets, for example, between a base station and a user equipment (UE).
1. A method of wireless communications by a receiver device, comprising:
buffering radio link control (RLC) protocol data units (PDUs) from a transmitter device, the RLC PDUs being generated from an original packet by using a network coding (NC) encoding algorithm;
recovering the original packet from the buffered RLC PDUs by using an NC decoding algorithm at a network coding sublayer of the receiver device;
generating a feedback, at the network coding sublayer, indicating a successful recovery of the original packet; and
providing the feedback to the transmitter device.
2. The method of claim 1 , wherein the feedback is provided to the transmitter device via a PDCP status report.
3. The method of claim 2 , wherein:
upon recovering the original PDCP packet from the buffered RLC PDUs, the network coding sublayer transfers the original PDCP packet to a PDCP layer of the receiver device; and
the PDCP layer generates the PDCP status report upon receiving the original PDCP packet from the network coding sublayer.
4. The method of claim 3 , wherein the PDCP status report also includes decoding information at the receiver.
5. The method of claim 4 , wherein the decoding information comprises at least one of a number of RLC PDUs used to recover the original packet or a number of iterations used to successfully recovery of the original packet.
6. The method of claim 1 , wherein the feedback is provided to the transmitter device via a RLC status report designed to indicate successful recovery of the original packet.
7. The method of claim 6 , wherein:
upon recovering the original PDCP packet from the buffered RLC PDUs, the network coding sublayer signals an RLC layer; and
the RLC layer generates the RLC status report upon receiving the signaling from the network coding sublayer.
8. The method of claim 6 , wherein the RLC status report also includes decoding information at the receiver.
9. The method of claim 8 , wherein the decoding information comprises at least one of a number of RLC PDUs used to recover the original packet or a number of iterations used to successfully recovery of the original packet.
10. The method of claim 1 , wherein the feedback is provided to the transmitter device via a hybrid automatic repeat request (HARQ) acknowledgment feedback generated at a medium access control (MAC) layer of the receiver device.
11. The method of claim 10 , wherein:
upon recovering the original PDCP packet from the buffered RLC PDUs, the network coding sublayer signals the MAC layer; and
the MAC layer takes one or more actions to stop receiving at least one of new MAC PDUs in response to the signaling from the network coding sublayer.
12. The method of claim 11 , wherein, if any one of the new MAC PDUs containing network coded packets is not allowed to multiplex packets from a different logical channel, the one or more actions comprise:
discarding the one MAC PDU in its entirety; and
providing a HARQ acknowledgment regardless of whether the one MAC PDU is successfully received or not.
13. The method of claim 11 , wherein, if one of the new MAC PDUs containing a network coded packet indicates multiplexing of packets from a different logical channel is allowed, the one or more actions comprise:
discarding any MAC PDU of the new MAC PDUs containing network coded packets not multiplexed with packets from a different logical channel; and
providing a positive acknowledgment regardless of whether the one of the new MAC PDU is successfully received or not.
14. A method of wireless communications by a transmitter device, comprising:
generating encoded packets from an original packet using a network coding (NC) encoding algorithm;
initiating a transmission of the encoded packets to a receiver device by forwarding the encoded packets to a radio link control (RLC) layer to generate RLC PDUs;
receiving a feedback from the receiver device indicating a successful receipt of the original packet; and
terminating the transmission of the encoded packets based on the feedback.
15. The method of claim 14 , wherein the NC encoding algorithm comprises at least one of Luby transform (LT) network coding or Raptor network coding.
16. The method of claim 14 , wherein:
the original packet comprises an original packet data convergence protocol (PDCP) packet; and
the transmitter device generates the RLC PDUs by dividing the original PDCP packet into source packets and generating the encoded packets from the source packets by using the NC encoding algorithm.
17. The method of claim 14 , wherein the feedback is received via a PDCP status report.
18. The method of claim 17 , further comprising:
upon receiving the PDCP status report, discarding any queued encoded packets associated with the terminated transmission; and
initiating a new original packet transmission with a new PDCP sequence number.
19. The method of claim 18 , wherein the PDCP status report also includes decoding information at the receiver.
20. The method of claim 19 , wherein the decoding information comprises at least one of a number of RLC PDUs used to recover the original packet or a number of iterations used to successfully recovery of the original packet.
21. The method of claim 19 , further comprising updating the NC encoding algorithm based on the decoding information.
22. The method of claim 14 , wherein the feedback is received via a RLC status report designed to indicate successful recovery of the original packet.
23. The method of claim 17 , further comprising:
upon receiving the RLC status report, discarding any queued RLC PDUs associated with the terminated transmission.
24. The method of claim 22 , wherein the RLC status report also includes decoding information at the receiver.
25. The method of claim 24 , wherein the decoding information comprises at least one of a number of RLC PDUs used to recover the original packet or a number of iterations used to successfully recovery of the original packet.
26. The method of claim 24 , further comprising updating the NC encoding algorithm based on the decoding information.
27. The method of claim 23 , further comprising ignoring any negative acknowledgment status report that indicates a retransmission of any of the discarded queued RLC PDUs.
28. The method of claim 14 , wherein the feedback is received by a medium access control (MAC) layer of the transmitter device via a hybrid automatic repeat request (HARM) acknowledgment feedback.
29. The method of claim 28 , further comprising:
continuing, via the MAC layer, to output MAC PDUs in a buffer for transmission until a higher layer initiates a new original packet transmission with a new PDCP sequence number.
30. A wireless node, comprising:
at least one antenna; and
a processing system configured to:
generate encoded packets from an original packet using a network coding (NC) encoding algorithm;
initiate, via the at least one antenna, a transmission of the encoded packets to a receiver device by forwarding the encoded packets to a radio link control (RLC) layer of the wireless node to generate RLC PDUs;
obtain, via the at least one antenna, a feedback from the receiver device indicating a successful receipt of the original packet; and
terminate the transmission of the encoded packets based on the feedback.