Determining and managing upstream profiles in DOCSIS 3.1 network environments

• US 9,660,774 B2
• Filed: 04/13/2015
• Issued: 05/23/2017
• Est. Priority Date: 04/14/2014
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Sowinski, Pawel Piotr, Jin, Hang, Liu, Tong
• Primary Examiner(s): Ho, Chuong T
• Application Number:
  US14/685,422
• Publication Number:
  US 20150295684A1
• Time in Patent Office: 771 Days
• Field of Search: 370252, 370254, 370390
• CPC Class Codes: H04B 3/542 the information being in digital form
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04J 3/0673 using intermediate nodes, e.g. modification of a received timestamp before further transmission to the next packet node, e.g. including internal delay time or residence time into the packet
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 27/2697 in combination with other modulation techniques
• CPC Class Codes: H04L 27/3405 Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power
• CPC Class Codes: H04L 27/345 Modifications of the signal space to allow the transmission of additional information
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/27 Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling

Abstract

An example method for determining and managing upstream profiles in Data Over Cable Service Interface Specification (DOCSIS) 3.1 network environments is provided and includes determining, at a Converged Cable Access Platform (CCAP) core, channel conditions independent of any channel effect over a hybrid fiber coaxial (HFC) network between a remote physical layer (R-PHY) entity coupled to the CCAP core and a cable modem (CM) in the DOCSIS 3.1 network environment, and assigning an upstream profile to the CM based on the channel conditions. In specific embodiments, the channel conditions include signal to noise ratio (SNR), modulation error ratio (MER) or group delay. In some embodiments, assigning the upstream profile includes determining a quadrature amplitude modulation (QAM) order based on the SNR or MER, and determining a pilot pattern based on the group delay, the combination of the QAM order and the pilot pattern identifying the upstream profile.

Claims

1. A method comprising:

determining, at a Converged Cable Access Platform (CCAP) core, channel conditions independent of any channel effect over a hybrid fiber coaxial (HFC) network between a remote physical layer (R-PHY) entity coupled to the CCAP core and a cable modem (CM) in a Data Over Cable Service Interface Specification (DOCSIS) 3.1 network environment; and

assigning an upstream profile to the CM based on the channel conditions including group delay and at least one of signal to noise ratio (SNR) and modulation error ratio (MER), wherein assigning the upstream profile comprises;

determining a quadrature amplitude modulation (QAM) order based on at least one of SNR and MER; and

determining a pilot pattern based on the group delay, wherein a combination of the QAM order and the pilot pattern identifies the upstream profile.

2. The method of claim 1, wherein the QAM order is determined from a lookup table (LUT) associating a QAM constellation indicative of the QAM order with SNR.

3. The method of claim 1, wherein the pilot pattern is determined from a LUT associating the group delay with the pilot pattern.

4. The method of claim 1, wherein the group delay is estimated through phase ramp in frequency domain.

5. The method of claim 1, further comprising sending a probing request to the CM for a probing signal comprising at least two probing opportunities, wherein the CM responds with the probing signal, wherein the channel conditions are determined from the probing signal.

6. The method of claim 5, wherein the determining the channel conditions independent of any channel effect comprises:

segmenting the probing signal according to channel variations;

for each segment, de-randomizing the probing signal for the at least two probing opportunities; and

for each segment, comparing the de-randomized probing signal for the at least two probing opportunities to remove any channel effects.

7. The method of claim 6, wherein the probing signal is segmented such that the SNR and channel variations remain relatively constant within each segment.

8. The method of claim 6, wherein if the SNR and group delay variation between any two segments is greater than a preconfigured threshold, the segmenting is repeated with smaller sized segments, wherein if the SNR and group delay variation between any two segments is less than another preconfigured threshold, the segment is repeated with larger sized segments.

9. Non-transitory tangible computer readable media that includes instructions for execution, which when executed by a processor, performs operations comprising:

determining, at a CCAP core, channel conditions independent of any channel effect over a HFC network between a R-PHY entity coupled to the CCAP core and a CM in a DOCSIS 3.1 network environment; and

assigning an upstream profile to the CM based on the channel conditions including group delay and at least one of SNR and MER, wherein assigning the upstream profile comprises;

determining a QAM order based on at least one of SNR and MER; and

determining a pilot pattern based on the group delay, wherein a combination of the QAM order and the pilot pattern identifies the upstream profile.

10. The media of claim 9, wherein the operations further comprise sending a probing request to the CM for a probing signal comprising at least two probing opportunities, wherein the CM responds with the probing signal, wherein the channel conditions are determined from the probing signal.

11. The media of claim 10, wherein the determining the channel conditions independent of any channel effect comprises:

segmenting the probing signal according to channel variations;

for each segment, de-randomizing the probing signal for the at least two probing opportunities; and

for each segment, comparing the de-randomized probing signal for the at least two probing opportunities to remove any channel effects.

12. The media of claim 11, wherein if the SNR and group delay variation between any two segments is greater than a preconfigured threshold, the segmenting is repeated with smaller sized segments, wherein if the SNR and group delay variation between any two segments is less than another preconfigured threshold, the segment is repeated with larger sized segments.

13. The media of claim 9, wherein the pilot pattern is determined from a LUT associating the group delay with the pilot pattern.

14. The media of claim 9, wherein the group delay is estimated through phase ramp in frequency domain.

15. An apparatus, comprising:

a CCAP core;

a memory element for storing data; and

a processor, wherein the processor executes instructions associated with the data, wherein the processor and the memory element cooperate, such that the apparatus is configured for;

determining, at the CCAP core, channel conditions independent of any channel effect over a HFC network between a R-PHY entity coupled to the CCAP core and a CM in a DOCSIS 3.1 network environment; and

assigning an upstream profile to the CM based on the channel conditions including group delay and at least one of SNR and MER, wherein assigning the upstream profile comprises;

determining a QAM order based on at least one of SNR and MER; and

determining a pilot pattern based on the group delay, wherein a combination of the QAM order and the pilot pattern identifies the upstream profile.

16. The apparatus of claim 15, further configured for sending a probing request to the CM for a probing signal comprising at least two probing opportunities, wherein the CM responds with the probing signal, wherein the channel conditions are determined from the probing signal.

17. The apparatus of claim 16, wherein the determining the channel conditions independent of any channel effect comprises:

segmenting the probing signal according to channel variations;

for each segment, de-randomizing the probing signal for the at least two probing opportunities; and

for each segment, comparing the de-randomized probing signal for the at least two probing opportunities to remove any channel effects.

18. The apparatus of claim 17, wherein if the SNR and group delay variation between any two segments is greater than a preconfigured threshold, the segmenting is repeated with smaller sized segments, wherein if the SNR and group delay variation between any two segments is less than another preconfigured threshold, the segment is repeated with larger sized segments.

19. The apparatus of claim 15, wherein the pilot pattern is determined from a LUT associating the group delay with the pilot pattern.

20. The apparatus of claim 15, wherein the group delay is estimated through phase ramp in frequency domain.