Scheduling mechanisms in full duplex cable network environments

• US 10,033,542 B2
• Filed: 02/24/2016
• Issued: 07/24/2018
• Est. Priority Date: 07/15/2015
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Jin, Hang, Chapman, John T.
• Primary Examiner(s): Nguyen, Thai
• Application Number:
  US15/052,466
• Publication Number:
  US 20170019239A1
• Time in Patent Office: 881 Days
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 49/70 Virtual switches
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001

Abstract

An example method for scheduling in full duplex cable network environments is provided and includes categorizing a plurality of cable modems in a cable network into interference groups, scheduling upstream transmissions and downstream receptions for cable modems in each interference group, such that no cable modem of any one interference group transmits upstream in a frequency range simultaneously as another cable modem in the same interference group receives downstream in the frequency range, generating scheduling information of the scheduling, and transmitting the scheduling information to the cable modems.

Claims

1. A method comprising:

categorizing a plurality of cable modems in a cable network into interference groups;

scheduling, by a cable modem termination system (CMTS) in the cable network, upstream transmissions and downstream receptions for cable modems in each interference group, such that no cable modem of any one interference group transmits upstream in a frequency range simultaneously as another cable modem in the same interference group receives downstream in the frequency range, wherein downstream transmission frequency is interleaved across a downstream symbol spanning a frequency range of an orthogonal frequency division multiplex block, wherein upstream transmission frequency is interleaved across an upstream symbol, wherein the upstream symbol is aligned with the downstream symbol;

generating scheduling information of the scheduling; and

transmitting the scheduling information to the cable modems.

2. The method of claim 1, further comprising scheduling cable modems in different interference groups to transmit upstream and receive downstream simultaneously in the frequency range.

3. The method of claim 1, wherein the cable modems are categorized into the interference groups through a ranging process.

4. The method of claim 1, wherein downstream transmission time is interleaved such that downstream data spans multiple symbols overlapped with each other, wherein upstream transmission time is not interleaved.

5. The method of claim 1, wherein the interference groups are sorted into interference blocks, wherein each interference block comprises a plurality of symbols including a symbol for guard time, wherein interleaving is implemented using the interference blocks.

6. The method of claim 1, wherein frequency interleaving is added to time interleaving, wherein symbols at each symbol time are rearranged according to a storage access scheme without introducing delay.

7. The method of claim 1, facilitating full duplex communication in the overall cable network across the frequency range and simplex communication in each individual interference group when the scheduling is implemented in distributed mode.

8. The method of claim 7, wherein the interference groups are identified by respective group labels, wherein downstream transmission in a frequency range to a particular interference group includes the particular interference group'"'"'s group label in a forward error correction (FEC) codeword, distinguishing the downstream transmission in the frequency range to the interference group from downstream transmission to other interference groups.

9. The method of claim 8, wherein the FEC codeword is several codewords in advance of other data in the downstream transmission to the interference group, allowing cable modems in the interference group to anticipate the other data ahead of actual reception, and scheduling upstream transmission accordingly.

10. The method of claim 8, wherein the cable modems in the interference group are not allowed to transmit upstream in the frequency range when the downstream FEC codeword is being received by the interference group.

11. Non-transitory tangible computer-readable media that includes instructions for execution, which when executed by a processor, is operable to perform operations comprising:

categorizing, by the processor disposed in a cable modem termination system (CMTS) in the cable network, a plurality of cable modems in a cable network into interference groups;

scheduling upstream transmissions and downstream receptions for cable modems in each interference group, such that no cable modem of any one interference group transmits upstream in a frequency range simultaneously as another cable modem in the same interference group receives downstream in the frequency range, wherein the interference groups are sorted into interference blocks, wherein each interference block comprises a plurality of symbols including a symbol for guard time, wherein interleaving is implemented using the interference blocks;

generating scheduling information of the scheduling; and

transmitting the scheduling information to the cable modems.

12. The non-transitory tangible computer-readable media of claim 11, wherein downstream transmission time is interleaved such that transmitted data spans multiple symbols overlapped with each other, wherein upstream transmission time is not interleaved.

13. The non-transitory tangible computer-readable media of claim 11, wherein downstream transmission frequency is interleaved across a downstream symbol spanning a frequency range of an orthogonal frequency division multiplex block, wherein upstream transmission frequency is interleaved across an upstream symbol, wherein the upstream symbol is aligned with the downstream symbol.

14. The non-transitory tangible computer-readable media of claim 11, facilitating full duplex communication in the overall cable network across the frequency range and simplex communication in each individual interference group when the scheduling is implemented in distributed mode.

15. The non-transitory tangible computer-readable media of claim 11, wherein frequency interleaving is added to time interleaving, wherein symbols at each symbol time are rearranged according to a storage access scheme without introducing delay.

16. An apparatus disposed in a cable modem termination system (CMTS) in a cable network, comprising:

a memory for storing data; and

a processor operable to execute instructions associated with the data, wherein the processor and the memory cooperate, such that the apparatus is configured for;

categorizing a plurality of cable modems in the cable network into interference groups;

scheduling upstream transmissions and downstream receptions for cable modems in each interference group, such that no cable modem of any one interference group transmits upstream in a frequency range simultaneously as another cable modem in the same interference group receives downstream in the frequency range, wherein frequency interleaving is added to time interleaving, wherein symbols at each symbol time are rearranged according to a storage access scheme without introducing delay;

generating scheduling information of the scheduling; and

transmitting the scheduling information to the cable modems.

17. The apparatus of claim 16, wherein downstream transmission time is interleaved such that transmitted data spans multiple symbols overlapped with each other, wherein upstream transmission time is not interleaved.

18. The apparatus of claim 16, wherein downstream transmission frequency is interleaved across a downstream symbol spanning a frequency range of an orthogonal frequency division multiplex block, wherein upstream transmission frequency is interleaved across an upstream symbol, wherein the upstream symbol is aligned with the downstream symbol.

19. The apparatus of claim 18, wherein the interference groups are sorted into interference blocks, wherein each interference block comprises a plurality of symbols including a symbol for guard time, wherein interleaving is implemented using the interference blocks.