Management system and methods of managing time-division duplex (TDD) transmission over copper
Time division duplex transmission over copper physical channels is managed. In one example, upstream time slots for upstream transmission in a first physical channel are scheduled. Downstream time slots for downstream transmission in a second physical channel are scheduled. Transmission in the upstream time slots is substantially not simultaneous with transmission in the downstream time slots.
1. A method in a data communications system for managing multiple physical channels that are subject to crosstalk, the method comprising:
scheduling upstream time slots for upstream transmission in a first physical channel; and
scheduling downstream time slots for downstream transmission in a second physical channel;
wherein during a portion of the upstream and downstream time slots, downstream transmission is simultaneous with upstream transmission; and
wherein near-end crosstalk (NEXT) cancellation at a network end of the channels reduces NEXT from downstream signals into upstream signals during the portion of the upstream and downstream time slots when downstream transmission is simultaneous with a portion of upstream transmission.
2. The method 1 of claim 1 , wherein downstream transmission is simultaneous with upstream transmission on some frequencies of some lines in cases where an amplitude of upstream NEXT received by downstream receivers is low.
3. The method of claim 1 , wherein an assignment of time-slot boundaries varies over time.
4. The method of claim 1 , wherein during another portion of the upstream and downstream time slots, downstream transmission is not simultaneous with upstream transmission.
5. The method of claim 1 , wherein:
a frequency band is allocated to downstream transmission, and a frequency band is allocated to upstream transmission; and
a portion of the frequency band allocated to downstream transmission does not overlap a portion of the frequency band allocated to upstream transmission.
6. The method of claim 1 , wherein:
during another portion of the upstream and downstream time slots, downstream transmission is not simultaneous with upstream transmission;
a frequency band is allocated to downstream transmission;
a frequency band is allocated to upstream transmission; and
a portion of the frequency band allocated to downstream transmission does not overlap a portion of the frequency band allocated to upstream transmission.
7. The method of claim 6 , wherein one or more of: time slot allocations and frequency band allocations, are dynamically adjusted for each traffic and transmission environment.
8. The method of claim 1 , wherein compatibility is enabled between a time division duplex (TDD) system and a frequency division duplex (FDD) system.
9. The method of claim 1 , wherein compatibility with a second system is supported by using dynamic spectrum management (DSM) methods.
10. The method of claim 1 , wherein the DSM methods are performed in one or more of: a remote management system, a cloud-based system, a virtual system, a transceiver, a digital subscriber line access multiplexer (DSLAM), a network element, and a distribution point unit (DPU).
11. A method in a data communications system for managing multiple time division physical channels that are subject to crosstalk, the method comprising: scheduling upstream time slots for upstream transmission in a first physical channel; scheduling downstream time slots for downstream transmission in a second physical channel wherein downstream transmission is simultaneous with upstream transmission, and wherein near-end crosstalk (NEXT) cancellation at a network end of the channels reduces NEXT from downstream signals into upstream signals during a portion of the upstream and downstream time slots when downstream transmission is simultaneous with a portion of upstream transmission; and time-slot boundaries are dynamically set and update the scheduling of the upstream time slots and the scheduling of the downstream time slots.
12. The method of claim 11 , wherein transmission in the upstream time slots is substantially not simultaneous with transmission in the downstream time slots.
13. The method of claim 11 , wherein the scheduling of the upstream time slots and the scheduling of the downstream time slots is dynamically set by changing the number of downstream symbol periods of the time division duplex (TDD) frame.
14. The method of claim 11 , wherein time-slot boundaries are dynamically set during operation where live user data are being transmitted without re-initialization of the transmission channel.
15. The method of claim 11 , wherein scheduling upstream time slots for upstream transmission in a first physical channel; and scheduling downstream time slots for downstream transmission in a second physical channel is performed upon request by a dynamic resource allocation (DRA) function.
16. The method of claim 11 , wherein scheduling upstream time slots for upstream transmission in a first physical channel; and scheduling downstream time slots for downstream transmission in a second physical channel is coordinated across multiple lines.
17. The method of claim 11 , wherein scheduling downstream time slots for downstream transmission in a second physical channel reduces the duration of at least one downstream time slot.
18. The method of claim 11 , wherein:
scheduling upstream time slots for upstream transmission in a first physical channel; and
scheduling downstream time slots for downstream transmission in a second physical channel applies to multiple contiguous time division duplex (TDD) frames.
19. The method of claim 11 , wherein:
scheduling upstream time slots for upstream transmission in a first physical channel; and
scheduling downstream time slots for downstream transmission in a second physical channel is based on one or more of: a bandwidth request, a bandwidth requirement, a traffic rate, a queue length, a current traffic demand, a traffic type, a traffic pattern, and a traffic request.
20. The method of claim 11 , wherein:
scheduling upstream time slots for upstream transmission in a first physical channel; and
scheduling downstream time slots for downstream transmission in a second physical channel uses data across multiple time slots.
21. The method of claim 11 , wherein:
scheduling upstream time slots for upstream transmission in a first physical channel; and
scheduling downstream time slots for downstream transmission in a second physical channel is changed after a traffic threshold is crossed.
22. The method of claim 11 , wherein retransmission units are sent at times that do not cause near end crosstalk (NEXT).
23. The method of claim 11 , wherein the ratio of downstream time slots for downstream transmission to upstream time slots for upstream transmission, is varied for one or more of the following purposes: to minimize traffic delays, and to maximize throughput, on one or more lines.
24. The method of claim 11 , wherein the management method is performed in one or more of: a remote management system, a cloud-based system, a virtual system, a transceiver, a digital subscriber line access multiplexer (DSLAM), and a distribution point unit (DPU).