Systems and methods for retransmission with on-line reconfiguration

• US 8,989,239 B2
• Filed: 05/07/2011
• Issued: 03/24/2015
• Est. Priority Date: 05/10/2010
• Status: Expired due to Fees

• Current Assignee: Ikanos Communications Incorporated (Qualcomm, Inc.)
• Original Assignee: Ikanos Communications Incorporated (Qualcomm, Inc.)
• Inventors: Schelstraete, Sigurd, Sorbara, Massimo
• Primary Examiner(s): Washburn, Daniel
• Assistant Examiner(s): HAILEGIORGIS, FITWI Y
• Application Number:
  US13/103,063
• Publication Number:
  US 20110274147A1
• Time in Patent Office: 1,417 Days
• Field of Search: 375/219, 375/147, 714/709, 714/748, 714/751, 370/352
• US Class Current: 375/219
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements

Abstract

Disclosed are various embodiments for performing retransmission with on-line reconfiguration. A data stream is encoded into first frames according to a framing configuration. A request is obtained for an on-line reconfiguration of the framing configuration from a receiver. The encoding of the data stream into the first frames is suspended in response to the request. One or more first frames are retransmitted to the receiver during a retransmission time period that commences relative to the suspending of the encoding of the data stream into the first frames. The encoding of the data stream into second frames is resumed according to a modified framing configuration consistent with the on-line reconfiguration. The second frames are transmitted to the receiver upon expiration of the retransmission time period.

Claims

1. A method implemented in a transmitter of a digital subscriber line (DSL) system, comprising the steps of:

encoding a data stream into a plurality of first frames according to a framing configuration;

obtaining a request for an on-line reconfiguration of the framing configuration from a receiver;

suspending the encoding of the data stream into the first frames in response to the request;

retransmitting at least one of the first frames to the receiver during a retransmission time period that occurs simultaneously with the suspending of the encoding of the data stream into the first frames;

resuming the encoding of the data stream into a plurality of second frames according to a modified framing configuration consistent with the on-line reconfiguration; and

transmitting the second frames to the receiver upon expiration of the retransmission time period.

2. The method of claim 1, further comprising the step of obtaining acknowledgement data from the receiver through a retransmission return channel, wherein the at least one of the first frames are retransmitted in response to the acknowledgement data.

3. The method of claim 1, wherein the retransmission time period is based at least in part on a size of a retransmission queue of the transmitter.

4. The method of claim 1, wherein the retransmission time period is based at least in part on a parameter that establishes a minimum level of impulse noise protection for a transmission channel between the transmitter and the receiver.

5. The method of claim 1, wherein the at least one of the first frames are retransmitted using at least one discrete multi-tone (DMT) symbol associated with a first data rate, and the second frames are transmitted using at least one DMT symbol associated with a second data rate that is different from the first data rate.

6. The method of claim 1, further comprising the step of transmitting an indication of when the retransmission time period expires to the receiver.

7. The method of claim 6, wherein the indication corresponds to an inverted sync symbol.

8. The method of claim 6, wherein the indication signals that the retransmission time period expires after a predefined number of discrete multi-tone (DMT) symbols are transmitted.

9. The method of claim 8, wherein the predefined number of DMT symbols is nine DMT symbols, and the on-line reconfiguration takes effect upon a tenth DMT symbol after the indication.

10. The method of claim 1, wherein the request for the on-line reconfiguration specifies a modified data rate to be employed by the transmitter in transmitting data to the receiver.

11. The method of claim 1, wherein the framing configuration specifies a frame size for the first frames, and the modified framing configuration specifies a different frame size for the second frames.

12. The method of claim 1, wherein the framing configuration specifies a forward error correction configuration for the first frames, and the modified framing configuration specifies a different forward error correction configuration for the second frames.

13. The method of claim 12, wherein the forward error correction configuration specifies a number of code words per frame for Reed-Solomon encoding, and the different forward error correction configuration specifies a different number of code words per frame for Reed-Solomon encoding.

14. The method of claim 12, wherein the forward error correction configuration specifies a level of redundancy for code words employed in Reed-Solomon encoding, and the different forward error correction configuration specifies a different level of redundancy for code words employed in Reed-Solomon encoding.

15. A system, comprising:

a transmitter for transmitting a data stream over a communications channel to a receiver, the transmitter comprising;

a framing encoder configured to encode the data stream into a plurality of frames according to a framing configuration; and

reconfiguration logic that performs an on-line reconfiguration of the communications channel, the reconfiguration logic comprising;

logic that suspends operation of the framing encoder according to the framing configuration;

logic that enables retransmission of at least one of the frames encoded according to the framing configuration during a retransmission state that occurs simultaneously with the operation of the framing encoder being suspended;

logic that resumes operation of the framing encoder according to a modified framing configuration consistent with the on-line reconfiguration; and

logic that disables transmission of frames encoded according to the modified framing configuration until the retransmission state ends.

16. The system of claim 15, wherein the transmitter further comprises a modulator configured to modulate the frames to at least one tone forming a discrete multi-tone (DMT) symbol according to a data rate, and wherein the reconfiguration logic further comprises logic that reconfigures the modulator to employ a different data rate consistent with the on-line reconfiguration upon ending of the retransmission state.

17. The system of claim 15, wherein the communication channel comprises a digital subscriber line (DSL) channel.

18. The system of claim 15, wherein the reconfiguration logic further comprises logic that obtains a request to perform the on-line reconfiguration from the receiver, wherein the on-line reconfiguration is performed in response to the request.

19. The system of claim 18, wherein the reconfiguration logic further comprises:

logic that determines whether to reject the request to perform the on-line reconfiguration; and

logic that transmits a notification to the receiver when the request is rejected.

20. The system of claim 15, wherein the on-line reconfiguration modifies a data rate of the communications channel.

21. The system of claim 15, wherein a duration of the retransmission state is determined based at least in part on a maximum number of retransmissions and a length of a retransmission queue.

22. The system of claim 15, wherein the reconfiguration logic further comprises logic that transmits a reconfiguration completion indication to the receiver that indicates when the retransmission state ends.

23. The system of claim 22, wherein the reconfiguration completion indication signals that the retransmission state ends after a predefined number of discrete multi-tone (DMT) symbols are transmitted.

24. A system, comprising:

a receiver for receiving a data stream over a communications channel from a transmitter, the receiver comprising;

logic that transmits a request for an on-line reconfiguration of the communications channel to the transmitter;

logic that obtains at least one retransmitted frame of the data stream from the transmitter after the request is transmitted, the at least one retransmitted frame being framed according to a first framing configuration;

logic that obtains an indication that signals that the on-line reconfiguration is to take effect in a predefined number of discrete multi-tone (DMT) symbols, wherein no initially transmitted frames of the data stream are obtained before the on-line reconfiguration takes effect after obtaining the indication; and

logic that obtains at least one frame of the data stream from the transmitter when the on-line reconfiguration takes effect, the at least one frame being framed according to a second framing configuration that is consistent with the on-line reconfiguration.

25. The system of claim 24, wherein the on-line reconfiguration modifies a data rate of the communications channel.

26. The system of claim 24, wherein the receiver further comprises a demodulator configured to demodulate at least one tone forming a discrete multi-tone (DMT) symbol into frames of the data stream.

27. The system of claim 24, wherein the receiver further comprises logic that sends a request for retransmission of at least one frame of the data stream to the transmitter.