Interference relationship characterization in full duplex cable network environments

• US 9,912,464 B2
• Filed: 02/24/2016
• Issued: 03/06/2018
• 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): Morlan, Robert M
• Application Number:
  US15/052,542
• Publication Number:
  US 20170019242A1
• Time in Patent Office: 741 Days
• CPC Class Codes: H04B 3/20 Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
• CPC Class Codes: H04B 3/32 Reducing cross-talk, e.g. by compensating
• CPC Class Codes: H04B 3/487 Testing crosstalk effects
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 5/1461 Suppression of signals in the return path, i.e. bidirectional control circuits

Abstract

An example method for characterizing interference relationships in full duplex cable network environments is provided and includes generating a global interfered list for a plurality of cable modems in the cable network and for a plurality of frequency ranges, generating a global interfering list for the plurality of cable modems and for the plurality of frequency ranges, assigning respective downstream reception frequency ranges and upstream transmission frequency ranges for the plurality of cable modems based on the global interfered list and the global interfering list, and transmitting to the cable modems corresponding assignment information comprising the respective assigned downstream reception frequency ranges and upstream transmission frequency ranges.

Claims

1. A method comprising:

generating a global interfered list for a plurality of cable modems in a cable network, the global interfered list comprising an aggregation of a plurality of interfered lists corresponding to a plurality of frequency ranges, each interfered list comprising cable modems whose downstream receptions are interfered by upstream transmissions of other cable modems in the corresponding frequency range;

generating a global interfering list for the plurality of cable modems, the global interfering list comprising an aggregation of a plurality of interfering lists corresponding to the plurality of frequency ranges, each interfering list comprising cable modems whose upstream transmissions interfere with downstream receptions of other cable modems in the corresponding frequency range;

assigning respective downstream reception frequency ranges and upstream transmission frequency ranges for the plurality of cable modems based on the global interfered list and the global interfering list; and

transmitting to the cable modems corresponding assignment information comprising the respective assigned downstream reception frequency ranges and upstream transmission frequency ranges.

2. The method of claim 1, wherein generating the global interfered list comprises:

generating, for a particular cable modem in the cable network, a respective interfered list associated with a particular one of the plurality of frequency ranges, the respective interfered list comprising a first list of cable modems whose downstream reception in the frequency range is interfered by upstream transmissions of the particular cable modem in the frequency range;

repeating generating the interfered list for other cable modems in the plurality of cable modems and for other frequency ranges in the plurality of frequency ranges; and

aggregating the generated interfered lists into the global interfered list.

3. The method of claim 2, wherein generating the respective interfered list for the particular cable modem comprises:

during a maintenance window, scheduling the particular cable modem to transmit a ranging signal within the particular one of the plurality of frequency ranges;

receiving reports indicative of interferences on respective downstream reception in the particular one of the plurality of frequency ranges from other cable modems in the cable network;

identifying cable modems that are interfered by the transmitting cable modem based on the reports; and

adding the identified cable modems to the first list.

4. The method of claim 2, wherein the particular cable modem is grouped with the first list of cable modems into an interference group for the frequency range.

5. The method of claim 2, wherein the particular cable modem is grouped into a plurality of interference groups corresponding to the plurality of frequency ranges, wherein downstream receptions of cable modems in each interference group for the corresponding frequency range are interfered by upstream transmissions of the cable modem in the corresponding frequency range.

6. The method of claim 1, wherein generating the global interfering list comprises:

generating, for a particular cable modem in the cable network, a respective interfering list associated with a particular one of the plurality of frequency ranges, the respective interfering list comprising a second list of cable modems whose upstream transmissions in the frequency range interfere with downstream reception of the particular cable modem in the frequency range;

repeating generating the interfering list for other cable modems in the plurality of cable modems and for other frequency ranges in the plurality of frequency ranges; and

aggregating the generated interfering lists into the global interfering list.

7. The method of claim 6, wherein generating the respective interfering list for the particular cable modem comprises deriving the second list of cable modems from the global interfered list.

8. The method of claim 1, wherein assigning respective downstream reception frequency ranges and upstream transmission frequency ranges comprises grouping cable modems into groups, each group being isolated on frequency basis from other groups, wherein cable modems in each group are assigned a common downstream reception frequency range and a common upstream transmission frequency range.

9. The method of claim 1, wherein the cable modems are grouped into interference groups with other cable modems connected to a commonly coupled amplifier in the cable network.

10. The method of claim 9, wherein the interference group is further divided into a plurality of sub-groups with relative isolation among the sub-groups, wherein each sub-group comprises cable modems attached to a corresponding common tap.

11. The method of claim 9, wherein cable modems in the interference group transmit upstream at a first frequency and receive downstream at a different frequency within the frequency range.

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

generating a global interfered list for a plurality of cable modems in a cable network, the global interfered list comprising an aggregation of a plurality of interfered lists corresponding to a plurality of frequency ranges, each interfered list comprising cable modems whose downstream receptions are interfered by upstream transmissions of other cable modems in the corresponding frequency range;

generating a global interfering list for the plurality of cable modems, the global interfering list comprising an aggregation of a plurality of interfering lists corresponding to the plurality of frequency ranges, each interfering list comprising cable modems whose upstream transmissions interfere with downstream receptions of other cable modems in the corresponding frequency range;

assigning respective downstream reception frequency ranges and upstream transmission frequency ranges for the plurality of cable modems based on the global interfered list and the global interfering list; and

transmitting to the cable modems corresponding assignment information comprising the respective assigned downstream reception frequency ranges and upstream transmission frequency ranges.

13. The media of claim 12, wherein generating the global interfered list comprises:

generating, for a particular cable modem in the cable network, a respective interfered list associated with a particular one of the plurality of frequency ranges, the respective interfered list comprising a first list of cable modems whose downstream reception in the frequency range is interfered by upstream transmissions of the particular cable modem in the frequency range;

repeating generating the interfered list for other cable modems in the plurality of cable modems and for other frequency ranges in the plurality of frequency ranges; and

aggregating the generated interfered lists into the global interfered list.

14. The media of claim 13, wherein generating the respective interfered list for the particular cable modem comprises:

during a maintenance window, scheduling the particular cable modem to transmit a ranging signal within the particular one of the plurality of frequency ranges;

receiving reports indicative of interferences on respective downstream reception in the particular one of the plurality of frequency ranges from other cable modems in the cable network;

identifying cable modems that are interfered by the transmitting cable modem based on the reports; and

adding the identified cable modems to the first list.

15. The media of claim 12, wherein generating the global interfering list comprises:

generating, for a particular cable modem in the cable network, a respective interfering list associated with a particular one of the plurality of frequency ranges, the respective interfering list comprising a second list of cable modems whose upstream transmissions in the frequency range interfere with downstream reception of the particular cable modem in the frequency range;

repeating generating the interfering list for other cable modems in the plurality of cable modems and for other frequency ranges in the plurality of frequency ranges; and

aggregating the generated interfering lists into the global interfering list.

16. The media of claim 12, wherein assigning respective downstream reception frequency ranges and upstream transmission frequency ranges comprises grouping cable modems into groups, each group being isolated on frequency basis from other groups, wherein cable modems in each group are assigned a common downstream reception frequency range and a common upstream transmission frequency range.

17. An apparatus, 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;

generating a global interfered list for a plurality of cable modems in a cable network, the global interfered list comprising an aggregation of a plurality of interfered lists corresponding to a plurality of frequency ranges, each interfered list comprising cable modems whose downstream receptions are interfered by upstream transmissions of other cable modems in the corresponding frequency range;

generating a global interfering list for the plurality of cable modems, the global interfering list comprising an aggregation of a plurality of interfering lists corresponding to the plurality of frequency ranges, each interfering list comprising cable modems whose upstream transmissions interfere with downstream receptions of other cable modems in the corresponding frequency range;

assigning respective downstream reception frequency ranges and upstream transmission frequency ranges for the plurality of cable modems based on the global interfered list and the global interfering list; and

transmitting to the cable modems corresponding assignment information comprising the respective assigned downstream reception frequency ranges and upstream transmission frequency ranges.

18. The apparatus of claim 17, wherein assigning respective downstream reception frequency ranges and upstream transmission frequency ranges comprises grouping cable modems into groups, each group being isolated on frequency basis from other groups, wherein cable modems in each group are assigned a common downstream reception frequency range and a common upstream transmission frequency range.

19. The apparatus of claim 17, wherein generating the global interfered list comprises:

generating, for a particular cable modem in the cable network, a respective interfered list associated with a particular one of the plurality of frequency ranges, the respective interfered list comprising a first list of cable modems whose downstream reception in the frequency range is interfered by upstream transmissions of the particular cable modem in the frequency range;

repeating generating the interfered list for other cable modems in the plurality of cable modems and for other frequency ranges in the plurality of frequency ranges; and

aggregating the generated interfered lists into the global interfered list.

20. The apparatus of claim 19, wherein generating the respective interfered list for the particular cable modem comprises:

during a maintenance window, scheduling the particular cable modem to transmit a ranging signal within the particular one of the plurality of frequency ranges;

receiving reports indicative of interferences on respective downstream reception in the particular one of the plurality of frequency ranges from other cable modems in the cable network;

identifying cable modems that are interfered by the transmitting cable modem based on the reports; and

adding the identified cable modems to the first list.