Method and apparatus for reducing transmission errors caused by periodic transients in digital subscriber line (DSL) communication systems
View Patent ↗A transient pre-emptor includes a processor configured to detect transients in a communications system. After the processor detects a transient in the communications system, it causes a data communications equipment to suspend or reduce data transmission during the occurrence of a subsequent transient.
1. A method for reducing transmission errors in a data communications equipment having a current transmission rate, the method comprising the steps of:
detecting a transient;
responsive to the detecting, collecting data describing one or more subsequent transients that occur over a first predetermined length of time;
determining, based on the collected data, a second time for rate adjustment; and
at the second time, reducing the current transmission rate from a first rate.
2. The method claim 1 , wherein the data comprises at least one of transient timing, transient duration, and transient rate.
3. The method of claim 1 , wherein the determining step bases the second time on variability of a cadence interval of the transient.
4. The method of claim 1 , further comprising the step of:
responsive to the detecting, reducing the current transmission rate from a second rate.
5. The method of claim 4 , further comprising the step of:
after the collecting step, restoring the current transmission rate to the second rate.
6. The method of claim 1 , further comprising the step of:
at a third time, restoring the current transmission rate to the first rate, the third time based on an expected time of a next transient occurrence.
7. The method of claim 1 , wherein the determining step bases the second time on at least one of a maximum duration of transmission of a pending message, a maximum duration for receiving a longest response message, and a duration of transmission of a rate reduction command.
8. A computer readable medium having a program for reducing transmission errors in a data communications equipment having a current transmission rate, the program comprising logic for performing the steps of:
detecting a transient;
responsive to the detecting, collecting data describing one or more subsequent transients that occur over a first predetermined length of time;
determining, based on the collected data, a second time for rate adjustment; and
at the second time, reducing the transmission rate or suspending transmission.
9. The computer readable medium of claim 8 , wherein the data comprises at least one of transient timing, transient duration, and transient rate.
10. The computer readable medium of claim 8 , wherein the determining step bases the second time on variability of a cadence interval of the transient.
11. The computer readable medium of claim 8 , further comprising the step of:
responsive to the detecting, reducing the transmission rate from a second rate.
12. The computer readable medium of claim 11 , further comprising the step of:
after the collecting step, restoring the transmission rate to the second rate.
13. The computer readable medium of claim 8 , further comprising the step of:
at a third time, restoring the transmission rate to the first rate, the third time based on an expected time of a next transient occurrence.
14. The computer readable medium of claim 8 , wherein the determining step bases the second time on at least one of a maximum duration of transmission of a pending message, a maximum duration for receiving a longest response message, and a duration of transmission of a rate reduction command.
15. A method for reducing transmission errors in a data communications equipment having a current transmission rate, the method comprising the steps of:
detecting a transient;
collecting data, responsive to the detecting, said data characterizing one or more subsequent transients that occur during a predetermined period;
determining, based on the collected data, a rate adjustment time; and
adjusting, at the rate adjustment time, the current transmission rate of the data communications equipment.
16. The method of claim 15 , wherein the collected data comprises at least one of transient timing, transient duration, and transient rate.
17. The method of claim 15 , further comprising the steps of:
determining, based on the collected data, an expected occurrence time of a subsequent transient start; and
reducing, at the expected occurrence time of the subsequent transient start, the current transmission rate of the data communications equipment.
18. The method of claim 17 , wherein the determining step bases the expected occurrence time on variability of a cadence interval of the transient.
19. The method of claim 17 , wherein the determining step bases the expected occurrence time on at least one of a maximum duration for transmission of a pending message, a maximum duration for receiving a longest response message, and a duration of transmission of a rate reduction command.
20. The method of claim 15 , further comprising the steps of:
determining, based on the collected data, an expected occurrence time of a subsequent transient end; and
restoring, at the expected occurrence time of the subsequent transient end, the current transmission rate of the data communications equipment.
21. The method of claim 20 , wherein the determining step bases the expected occurrence time on variability of a cadence interval of the transient.
22. The method of claim 20 , wherein the determining step bases the expected occurrence time on at least one of a maximum duration for transmission of a pending message, a maximum duration for receiving a longest response message, and a duration of transmission of a rate reduction command.