QAM signal analysis in a network

• US 20050281200A1
• Filed: 06/16/2004
• Published: 12/22/2005
• Est. Priority Date: 06/16/2004
• Status: Abandoned Application

• Current Assignee: Sunrise Telecom Incorporated
• Original Assignee: Sunrise Telecom Incorporated
• Inventors: Terreault, Gerard
• Application Number:
  US10/868,209
• Publication Number:
  US 20050281200A1
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336

Abstract

A system and method for maintaining an uninterrupted data flow in a communications network includes a transmitter, which transmits the data flow from a data source and a receiver, which receives the data flow. A channel interconnects the transmitter and the receiver, and communicates the data flow between the transmitter and the receiver. A switch is located in the channel between the transmitter and the receiver. The switch is openable for a period of time, which is sufficient to permit analysis of signal impairment in the channel without interrupting the data flow.

Claims

1. A system for maintaining an uninterrupted data flow in a communications network, the system comprising:

a) a transmitter for transmitting the data flow from a data source;

b) a receiver for receiving the data flow;

c) a channel interconnecting the transmitter and the receiver, the data flow being communicated between the transmitter and the receiver through the channel; and

d) a switch located in the channel and disposed between the transmitter and the receiver, the switch being openable for a period of time sufficient to permit analysis of signal impairment in the channel without interrupting the data flow.

2. The system, according to claim 1, in which:

a) the data flow transmitter includes a QAM modulator.

3. The system, according to claim 2, in which:

a) an up-converter is connected downstream of the switch and the QAM modulator.

4. The system, according to claim 3, in which:

a) a link connects the QAM modulator and the up-converter.

5. The system, according to claim 4, in which:

a) the link is an Intermediate Frequency (IF) link.

6. The system, according to claim 1, in which:

a) the switch is a gated switch.

7. The system, according to claim 6, in which:

a) the switch is a high-speed switch, the switch being located either at an output of the up-converter or between the QAM modulator and the up-converter.

8. The system, according to claim 1, in which:

a) the data flow has a burst protection period.

9. The system, according to claim 1, in which:

a) the data flow has a channel coding scheme with a pre-determined burst protection period.

10. The system, according to claim 8, in which:

a) the switch cuts-off for an interruption period sufficient to cause an interruption of the transmitted data flow.

11. The system, according to claim 10, in which:

a) the interruption period is shorter than the burst protection period.

12. The system, according to claim 11, in which:

a) the interruption period is between 10% and 90% of the burst protection period.

13. The system, according to claim 12, in which:

a) the interruption period is between 40% and 60% of the burst protection period.

14. The system, according to claim 13, in which:

a) the interruption period is about 50% of the burst protection period.

15. The system, according to claim 14, in which:

a) the burst protection is 66 μ

sec.

16. The system, according to claim 15, in which:

a) the interruption period is 33 μ

sec.

17. The system, according to claim 1, in which:

a) the communications network is a CATV network.

32. The system, according to claim 12, in which:

a) the interruption period is between 40% and 60% of the burst protection period.

33. The method, according to claim 32, in which:

a) the interruption period is about 50% of the burst protection period.

34. The method, according to claim 33, in which:

a) the burst protection is 66 μ

sec.

35. The method, according to claim 34, in which:

a) the interruption period is 33 μ

sec.

18. A method of maintaining uninterrupted data flow in a communications network during signal analysis, the network having a transmitter in communication with a receiver, the method comprising:

a) temporarily removing a portion of the data flow from a communications channel, the channel communicating the data flow between the transmitter and the receiver; and

b) measuring a source of signal impairment in the channel so as to maintain uninterrupted data flow to the receiver.

19. The method, according to claim 18, in which:

a) a switch is located in the channel and disposed between the transmitter and the receiver, the switch being openable for a period of time sufficient to permit analysis of signal impairment in the channel without interrupting the data flow.

20. The method, according to claim 18, in which:

a) the data flow transmitter includes a QAM modulator.

21. The method, according to claim 20, in which:

a) an up-converter is connected downstream of the switch and the QAM modulator.

25. The method, according to claim 19, in which:

a) the switch is a gated switch.

26. The method, according to claim 25, in which:

a) the switch is a high-speed switch, the switch being located either at an output of the up-converter or between the QAM modulator and the up-converter.

27. The method, according to claim 18, in which:

a) the data flow has a burst protection period.

28. The method, according to claim 18, in which:

a) the data flow has a channel coding scheme with a pre-determined burst protection period.

29. The method, according to claim 26, in which:

a) the switch cuts-off for an interruption period sufficient to cause an interruption of the transmitted data flow.

30. The method, according to claim 29, in which:

a) the interruption period is shorter than the burst protection period.

31. The method, according to claim 30, in which:

a) the interruption period is between 10% and 90% of the burst protection period.

36. The method, according to claim 18, in which:

a) the communications network is a CATV network.

23. The method, according to claim 22, in which:

a) a link connects the QAM modulator and the up-converter.

24. The method, according to claim 23, in which:

a) the link is an Intermediate Frequency (IF) link.