Energy monitoring in a communciation link

• US 9,622,097 B2
• Filed: 02/13/2015
• Issued: 04/11/2017
• Est. Priority Date: 02/13/2014
• Status: Active Grant

• Current Assignee: Cable Television Laboratories Incorporated
• Original Assignee: Cable Television Laboratories Incorporated
• Inventors: Williams, Thomas H.
• Primary Examiner(s): Liu, Shuwang
• Assistant Examiner(s): Ahn, Sung
• Application Number:
  US14/621,842
• Publication Number:
  US 20150229416A1
• Time in Patent Office: 788 Days
• CPC Class Codes: H04B 3/46 Monitoring; Testing
• CPC Class Codes: H04N 21/42676 for modulating an analogue carrier signal to encode digital information or demodulating it to decode digital information, e.g. ADSL or cable modem
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

Systems and methods presented herein provide for monitoring of noise and other interfering energy on a communication link. One system includes an interface coupled to the communication link to receive a signal conveyed over the communication link. The system also includes a monitor operable to: track energy across a frequency spectrum of the signal conveyed over the communication link for a predetermined period of time; flag, at intervals of the predetermined period of time, energy levels across the frequency spectrum of the signal that breach a threshold energy level to identify where in the frequency spectrum a breach of the threshold energy level occurs; and add the flags to determine how long the threshold energy level was breached during the predetermined period of time.

Claims

1. A cable television communication system operable to monitor a communication link in the system, the system comprising:

an interface of a Cable Modem Termination System (CMTS) coupled to the communication link to receive a signal conveyed over the communication link; and

a monitor operable to;

track energy across a frequency spectrum of the signal conveyed over the communication link for a predetermined period of time;

flag, at intervals of the predetermined period of time, energy levels across the frequency spectrum of the signal that breach a threshold energy level to identify where in the frequency spectrum a breach of the threshold energy level occurs; and

add the flags to determine how long the threshold energy level was breached during the predetermined period of time,

wherein;

the communication link is an opto-electrical communication link;

the signal is an optical communication signal conveying a digitized upstream Radio Frequency (RF) signal of the cable television communication system, and

the monitor is further operable to direct a node of the cable television communication system to change a modulation scheme of the RF signal to overcome interfering energy in the signal.

2. The system of claim 1, wherein:

the monitor is operable to generate a grid plot of the energy of the signal in a frequency-versus-time format for the predetermined period of time.

3. The system of claim 1, further comprising:

a processor operable to reset the monitor, and to direct the monitor to monitor the communication link for another predetermined period of time.

4. The system of claim 1, wherein the monitor comprises:

an amplifier operable to output a Direct Current (DC) signal having a voltage proportional to a voltage of the signal conveyed over the communication link; and

an accumulator operable to track the voltage of the DC signal for the predetermined period of time, to generate a flag at discrete voltage levels when the voltage of the DC signal breaches each discrete voltage level, and to add each flag at each discrete voltage level to determine how long each discrete voltage level was breached during the predetermined period of time.

5. The system of claim 1, wherein:

the monitor comprises a detector operable to accumulate an amount of the interfering energy in the signal, and to recommend an error correction scheme that will be effective given the amount of the interfering energy in the signal.

6. The system of claim 1, further comprising:

a detector operable to accumulate an amount of the interfering energy in the signal, wherein the detector comprises;

a filter operable to isolate a data signal in the signal conveyed over the communication link;

an Alternating Current to Direct Current (AC-DC) converter operable to generate a time varying DC signal from the filtered data signal;

a multiplier operable to generate a time varying power signal from the time varying DC signal; and

an integrator operable to accumulate the interfering energy in the data signal.

7. A method for monitoring a communication link in a cable television communication system, the method comprising:

interfacing a Cable Modem Termination System (CMTS) with the communication link to receive a signal conveyed over the communication link;

tracking energy across a frequency spectrum of the signal for a predetermined period of time;

flagging, at intervals of the predetermined period of time, energy levels across the frequency spectrum of the signal that breach a threshold energy level to identify where in the frequency spectrum a breach of the threshold energy level occurs; and

adding the flags to determine how long the threshold energy level was breached during the predetermined period of time

wherein;

the communication link is an opto-electrical communication link;

the signal is an optical communication signal conveying a digitized upstream Radio Frequency (RF) signal of a cable television communication system, and

the method further comprises directing a node of the cable television communication system to change a modulation scheme of the RF signal to overcome interfering energy in the signal.

8. The method of claim 7, further comprising:

generating a grid plot of the energy of the signal in a frequency-versus-time format for the predetermined period of time.

9. The method of claim 7, further comprising:

flushing the added flags after the predetermined period of time; and

monitoring the communication link for another predetermined period of time in response to flushing the added flags.

10. The method of claim 7, further comprising:

amplifying the signal to generate a Direct Current (DC) signal having a voltage proportional to a voltage of the signal conveyed over the communication link;

tracking the voltage of the DC signal for the predetermined period of time;

generating a flag at discrete voltage levels when the voltage of the DC signal breaches each discrete voltage level; and

adding each flag at each discrete voltage level to determine how long each discrete voltage level was breached during the predetermined period of time.

11. The method of claim 7, further comprising:

accumulating an amount of the interfering energy in the signal; and

recommending an error correction scheme that will be effective given the amount of the interfering energy in the signal.

12. The method of claim 7, further comprising:

accumulating an amount of the interfering energy in the signal, wherein accumulating comprises;

filtering the signal to isolate a data signal in the signal conveyed over the communication link;

generating a time varying DC signal from the filtered data signal;

generating a time varying power signal from the time varying DC signal; and

integrating the DC signal to accumulate the interfering energy in the data signal.