Ingress testing of CATV system utilizing remote selection of CATV node

• US 6,425,132 B1
• Filed: 04/06/1998
• Issued: 07/23/2002
• Est. Priority Date: 04/06/1998
• Status: Expired due to Term

• Current Assignee: Wavetek Corp. (Lumentum Holdings Inc.)
• Original Assignee: Wavetek Corp. (Lumentum Holdings Inc.)
• Inventors: Chappell, Daniel K.
• Primary Examiner(s): Faile, Andrew
• Assistant Examiner(s): HUYNH, AN SON PHI
• Application Number:
  US09/055,664
• Time in Patent Office: 1,569 Days
• Field of Search: 725/107, 725/124-125, 725/106, 348/180, 348/192-193, 324/500, 324/512, 324/522, 324/528, 324/531-535, 324/750, 455/67.1, 455/67.3, 455/67.4, 379/1-2, 379/6, 379/12, 379/19, 379/26-27, 379/34
• US Class Current: 725/107
• CPC Class Codes: H04N 17/00 Diagnosis, testing or measuring for television systems or their details
• CPC Class Codes: H04N 21/2221 being a cable television head-end CATV in broadcast systems H04H20/78
• CPC Class Codes: H04N 21/2404 Monitoring of server processing errors or hardware failure error or fault detection G06F11/07; monitoring in general G06F11/30
• CPC Class Codes: H04N 21/2408 Monitoring of the upstream path of the transmission network, e.g. client requests monitoring data switching networks utilization H04L43/0876; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/6168 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications

Abstract

A CATV system in which a technician in the field requests via a field client that a node of the CATV system be tested for ingress. The CATV system includes a headend facility that is coupled to a CATV distribution network. The CATV distribution network includes a plurality of nodes through which upstream signals are transmitted to the headend facility. A method of ingress testing for use in the CATV system includes one step of receiving at the headend facility a first reverse telemetry signal transmitted by a first field client that is coupled to the CATV distribution network at a first location downstream from the headend facility. Another step of the method includes selecting at the headend facility a first test node from the plurality of nodes of the CATV distribution network, wherein the selection is based upon the received first reverse telemetry signal. The method also includes the step of measuring first upstream signals from the selected first test node to obtain a first plurality of measurement values for the first upstream signals. Finally, the method includes transmitting from the headend facility via the CATV distribution network a forward telemetry signal that includes the first plurality of measurement values.

Claims

1. A method of testing a CATV system having a headend facility that is coupled to a CATV distribution network that includes a plurality of nodes through which upstream signals are transmitted to the headend facility, comprising the steps of:

a) receiving at said headend facility a first reverse telemetry signal transmitted by a first field client that is coupled to said CATV distribution network at a first location downstream from said headend facility;

b) selecting at said headend facility a first test node from said plurality of nodes of said CATV distribution network based upon said first reverse telemetry signal;

c) measuring first upstream signals from said first test node to obtain a first plurality of measurement values for said first upstream signals; and

d) transmitting from said headend facility via said CATV distribution network, a forward telemetry signal that includes said first plurality of measurement values.

2. The method of claim 1 further comprising the steps of:

e) receiving at said first field client said forward telemetry signal that includes said first plurality of measurement values; and

f) displaying at said first field client, indicia of said first plurality of measurement values.

3. The method of claim 1 wherein step c) further comprises obtaining from said first upstream signals a separate measurement value for each frequency of a plurality of frequencies in order to obtain said first plurality of measurement values.

4. The method of claim 1 wherein step c) further comprises:

tuning to a first frequency and measuring a first frequency component of said first upstream signals to obtain a first measurement value of said first plurality of measurement values; and

tuning to a second frequency and measuring a second frequency component of said first upstream signals to obtain a second measurement value of said first plurality of measurement values.

5. The method of claim 1 further comprising the steps of:

e) receiving at said headend facility a second reverse telemetry signal transmitted by a second field client that is coupled to said CATV distribution network at a second location downstream from said headend facility;

f) selecting at said headend facility a second test node from said plurality of nodes based upon said second reverse telemetry signal; and

g) measuring second upstream signals from said second test node to obtain a second plurality of measurement values for said second upstream signals;

wherein said step d) further comprises transmitting from said headend facility via said CATV distribution network said forward telemetry signal wherein said forward telemetry signal further includes said second plurality of measurement values.

6. The method of claim 5 further comprising the steps of:

h) receiving at said second field client said forward telemetry signal that includes said first plurality of measurement values and said second plurality of measurement values;

i) determining at said second field client that said second plurality of measurement values are for the second test node; and

j) displaying at said second field client indicia of said second plurality of measurement values.

7. The method of claim 1, wherein:

step a) further comprises receiving at said headend facility said first reverse telemetry signal wherein said first reverse telemetry, signal further includes a channel plan; and

step c) further comprises obtaining from said upstream signals a separate measurement value for each frequency of a plurality of frequencies in order to obtain said first plurality of measurement values, wherein said plurality of frequencies corresponds to said channel plan.

8. A method of testing a CATV system having a headend facility that is coupled to a CATV distribution network that includes a plurality of nodes through which upstream signals are transmitted to the headend facility, comprising the steps of:

a) receiving at said headend facility a first reverse telemetry signal from a first field client that is coupled to said CATV distribution network at a first location downstream from said headend facility, wherein said first reverse telemetry signal includes a first node identifier;

b) receiving at said headend facility a second reverse telemetry signal from a second field client that is coupled to said CATV distribution network at a second location downstream from said headend facility, wherein said second reverse telemetry signal includes a second node identifier;

c) obtaining at said headend facility a first plurality of measurement values for first upstream signals received from a first test node selected based upon said first node identifier of said first reverse telemetry signal;

d) obtaining at said headend facility a second plurality of measurement values for second upstream signals received from a second test node selected based upon said second node identifier of said second reverse telemetry signal; and

e) transmitting from said headend facility to said first field client and said second field client via said CATV distribution network a forward telemetry signal that includes (i) said first plurality of measurement values, (ii) said first node identifier which associates said first plurality of measurement values with said first test node, (iii) said second plurality of measurement values, and (iv) said second node identifier which associates said second plurality of measurement values with said second test node.

9. The method of claim 8 wherein step c) further comprises obtaining from said first upstream signals a separate measurement value for each frequency of a plurality of frequencies in order to obtain said first plurality of measurement values.

10. The method of claim 8 wherein step c) further comprises:

tuning to a first frequency and measuring a first frequency component of said first upstream signals to obtain a first measurement value of said first plurality of measurement values; and

tuning to a second frequency and measuring a second frequency component of said first upstream signals to obtain a second measurement value of said first plurality of measurement values.

11. The method of claim 8 further comprising the steps of:

f) receiving at said first field client said forward telemetry signal;

g) determining at said first field client and from said first node identifier of said forward telemetry signal that said first plurality of measurement values are associated with said first test node; and

h) displaying at said first field client indicia of said first plurality of measurement values.

12. The method of claim 8 wherein:

step a) further comprises receiving at said headend facility said first reverse telemetry signal wherein said first reverse telemetry signal further includes a channel plan; and

step c) further comprises obtaining from said first upstream signals a separate measurement for each of a plurality of frequencies in order to obtain said first plurality of measurement values, wherein said plurality of frequencies corresponds to said channel plan.

13. A method of testing a CATV system having a headend facility coupled to a CATV distribution network that includes a plurality of nodes through which upstream signals are transmitted to the headend facility, the method comprising:

a) receiving at said headend facility a reverse RF signal which includes (i) a first reverse telemetry signal from a first field client, and (ii) a second reverse telemetry signal from a second field client, wherein said first reverse telemetry signal is modulated upon a first carrier having a reverse telemetry frequency and said second telemetry signal is modulated upon a second carrier having said reverse telemetry frequency;

b) obtaining at said headend facility a signal level measurement of a frequency component of said reverse RF signal which corresponds to said reverse telemetry frequency;

c) transmitting from said headend facility to said first field client and said second field client via said CATV distribution network, a first forward telemetry signal that includes said signal level measurement of said reverse RF signal; and

d) determining at said first field client and from said signal level measurement included in said first forward telemetry signal that a reverse telemetry collision has occurred.

14. The method of claim 13 further comprising the step of:

e) re-transmitting said first reverse telemetry signal as a third reverse telemetry signal from said first field client to said headend facility in response to determining that said reverse telemetry collision occurred.

15. The method of claim 13 further comprising the step of:

e) re-transmitting said first reverse telemetry signal from said first field client to said headend facility after a period of time from determining that said reverse telemetry collision occurred.

16. The method of claim 14 further comprising the steps of:

f) receiving at said headend facility said third reverse telemetry signal;

g) selecting a first test node from said plurality of nodes based upon said third reverse telemetry signal;

h) measuring at said headend facility first upstream signals received from said first test node to obtain a first plurality of measurement values for said first upstream signals;

i) transmitting from said headend facility to said first field client and said second field client a second forward telemetry signal that includes said first plurality of measurement values;

j) receiving at said first field client said second forward telemetry signal that includes said first plurality of measurement values; and

k) displaying at said first field client indicia of said first plurality of measurement values in response to receiving at said first field client said second forward telemetry signal.

17. The method of claim 16, wherein step h) further comprises obtaining from said first upstream signals a separate measurement value for each frequency of a plurality of frequencies in order to obtain said first plurality of measurement values.

18. The method of claim 17 wherein:

step a) further comprises receiving from said first field client said third reverse telemetry signal wherein said third reverse telemetry signal further includes a first node identifier;

step i) further comprises transmitting from said headend facility to said first field client and said second field client said second forward telemetry signal, wherein said second forward telemetry signal further includes said first node identifier which associates said first plurality of measurement values of said forward telemetry signal with said first test node;

step j) further comprises receiving at said first field client said second forward telemetry signal including said first node identifier; and

step k) further comprises determining at said first field client and from said first node identifier of said forward telemetry signal that said first plurality of measurement values are associated with said first test node.

19. An ingress modem for testing a CATV system that includes (i) a CATV distribution network having a plurality of nodes through which upstream signals are transmitted, and (ii) a test point switch coupled to said plurality of nodes, said ingress modem comprising:

an RF output jack operable to couple to said CATV distribution network;

an RF input jack operable to couple to said test point switch;

a communication line coupled to said test point switch;

an RF receiver coupled to said RF input jack and operable to (i) receive from said RF input jack a first reverse telemetry signal transmitted by a first field client coupled to said CATV distribution network at a first location, said first reverse telemetry signal including a first node identifier that identifies a first test node of said plurality of nodes, and (ii) measure first upstream signals received from said first test node to obtain a first plurality of measurement values for said first upstream signals;

an RF transmitter coupled to said RF output jack and operable to transmit to said first field client via said CATV distribution network, a forward telemetry signal that includes said first plurality of measurement values for said first upstream signals; and

a controller coupled. to said RF receiver, said RF transmitter, and said communication line, wherein said controller is operable to i) control operation of said RF receiver and said RF transmitter, ii) receive said first node identifier of said first reverse telemetry signal from said RF receiver, and iii) transmit to said test point switch via said communication line, a first control signal that is indicative of said first node identifier in order to cause said test point switch to provide said RF receiver with said first upstream signals.

20. The ingress modem of claim 19 wherein said RF receiver is further operable to obtain from said first upstream signals a separate measurement value for each frequency of a plurality of frequencies in order to obtain said first plurality of measurement values.

21. The ingress modem of claim 19 wherein said RF receiver is further operable to:

i) tune to a first frequency and measure a first frequency component of said first upstream signals to obtain a first measurement value of said first plurality of measurement values; and

ii) tune to a second frequency and measure a second frequency component of said first upstream signals to obtain a second measurement value of said first plurality of measurement values.

22. The ingress modem of claim 19 wherein:

said RF receiver is further operable to (i) receive a second reverse telemetry signal transmitted by a second field client coupled to said CATV distribution network, wherein said second reverse telemetry signal includes a second node identifier that identifies a second test node of said plurality of nodes, and (ii) measure second upstream signals received from said second test node to obtain a second plurality of measurement values for said second upstream signals;

said RF transmitter is further operable to transmit to said second field client via said CATV distribution network, said forward telemetry signal that further includes said second plurality of measurement values and said second node identifier which associates said second plurality of measurement values with said second test node; and

said controller is further operable to (i) receive said second node identifier of said second telemetry signal from said RF receiver, and (ii) transmit to said test point switch via said communication port, a second control signal that is indicative of said second node identifier in order to cause said test point switch to provide said RF receiver with said second upstream signals.

24. The ingress modem of claim 19 further comprising said test point switch.

23. The ingress modem of 19 wherein:

said RF receiver is further operable to (i) receive a channel plan that is included in said first reverse telemetry signal; and

(ii) provide said controller with said channel plan; and

said controller is further operable to cause said RF receiver to obtain a separate measurement value for each frequency of a plurality of frequencies in order to measure said first upstream signals, wherein said plurality of frequencies corresponds to said channel plan.

25. A CATV system having a reverse path testing capability, the system comprising:

a CATV distribution network comprising a plurality of nodes through which upstream signals are transmitted to said headend facility;

a test point switch coupled to said plurality nodes and operable to electrically couple a first test node of said plurality of nodes to said RF receiver in response to a first control signal that is indicative of a first node identifier being provided to a node selection input of said test point switch;

a first field client coupled to said CATV distribution network at a first location downstream from said headend facility, wherein said first field client is operable to transmit a first reverse telemetry signal that includes said first node identifier that identifies said first test node of said plurality of nodes;

a RF receiver coupled to said test point switch and operable to (i) receive from said test point switch, a reverse RF signal that includes said first reverse telemetry signal, and (ii) measure first upstream signals received from said first test node to obtain a first plurality of measurement values for said first upstream signals;

a RF transmitter coupled to the CATV distribution network and operable to transmit to said first field client via said CATV distribution network a forward telemetry signal that includes said first plurality of measurement values for said first upstream signals; and

a controller coupled to said RF receiver, said RF transmitter, and said test point switch and operable to (i) control operation of said RF receiver and said RF transmitter, and (ii) cause said test point switch to electrically couple said first test node to said RF receiver by providing said first control signal to said node selection input.

26. The CATV system of claim 25 wherein said RF receiver is further operable to obtain from said first upstream signals a separate measurement value for each frequency of a plurality of frequencies in order to obtain said first plurality of measurement values.

27. The CATV system of claim 25 wherein said RF receiver is further operable to:

i) tune to a first frequency and measure a first frequency component of said first upstream signals to obtain a first measurement value of said first plurality of measurement values; and

ii) tune to a second frequency and measure a second frequency component of said first upstream signals to obtain a second measurement value of said first plurality of measurement values.

28. The CATV system of claim 25 further comprising a second field client coupled to said CATV distribution network at a second location downstream from said headend facility, and wherein:

said second field client is operable to transmit a second reverse telemetry signal that includes a second node identifier that identifies a second test node of said plurality of nodes;

said RF receiver is further operable to (i) receive from said test point switch said second reverse telemetry signal as part of said reverse RF signal, and (ii) measure second upstream signals received from said second test node to obtain a second plurality of measurement values for said second upstream signals;

said test point switch is further operable to electrically couple said second test node to said node output in response to a second control signal indicative of said second node identifier being provided to said node selection input;

said RF transmitter is further operable to transmit via said CATV distribution network, said forward telemetry signal, wherein said forward telemetry signal further includes (i) said second plurality of measurement values for said second upstream signals and (ii) said second node identifier which associates said second plurality of measurement values with said second test node; and

said controller is further operable to cause said test point switch to electrically couple said second test node to said RF receiver by providing said second control signal to said node selection input.

29. The CATV system of claim 28 wherein said second field client is further operable to:

i) receive said forward telemetry signal that includes said first plurality of measurement values, said second plurality of measurement values, and said second node identifier;

ii) determine from said second node identifier of said forward telemetry signal that said second plurality of measurement values are associated with said second test node; and

iii) display indicia of said second plurality of measurement values in response to determining that said second plurality of measurement values are associated with said second test node.

30. The CATV system of claim 25 wherein:

said first field client is further operable to transmit a channel plan that is included within said first reverse telemetry signal;

said RF receiver is further operable to (i) receive said first reverse telemetry signal including said channel plan, and (ii) provide said channel plan to said controller; and

said controller is further operable to cause said RF receiver to obtain from said upstream signals a separate measurement value for each frequency of a plurality of frequencies, in order to obtain first plurality of measurement values, wherein said plurality of frequencies corresponds to said channel plan.

31. A CATV system having a reverse path testing capability, the system comprising:

a CATV distribution network comprising a plurality of nodes through which upstream signals are transmitted;

a first field client coupled to said CATV distribution network at a first location, wherein said first field client is operable to transmit a first reverse telemetry signal that is modulated upon a first carrier having a reverse telemetry frequency;

a second field client coupled to said CATV distribution network at a second location, wherein said second field client is operable to transmit a second reverse telemetry signal that is modulated upon a second carrier having said reverse telemetry frequency;

an RF receiver coupled to said test point switch and operable to (i) receive from said test point switch an RF signal that includes said first reverse telemetry signal and said second reverse telemetry signal, and (ii) obtain a signal level measurement of said reverse RF signal at said reverse telemetry frequency;

an RF transmitter coupled to the CATV distribution network and operable to transmit a first forward telemetry signal to said first field client and said second field client via said CATV distribution network, said first forward telemetry signal including said signal level measurement of said reverse RF signal;

and wherein said first field client is further operable to receive said first forward telemetry signal and determine from the signal level measurement included in said first forward telemetry signal that a reverse telemetry collision has occurred.

32. The CATV system of claim 31 wherein said first field client is further operable to re-transmit said first reverse telemetry signal as a third telemetry signal in response to determining that a reverse telemetry collision occurred.

33. The CATV system of claim 31 wherein said first field client is further operable to re-transmit said first reverse telemetry signal after a period of time has expired from determining that a reverse telemetry collision occurred.

34. The CATV system of claim 32 further comprising:

a test point switch coupled to said plurality nodes;

a controller coupled to said RF receiver and said RF transmitter for controlling said RF receiver and said RF transmitter; and

wherein

said test point switch is operable to electrically couple a first test node of said plurality of nodes to said RF receiver in response to a first control signal that is indicative of a first node identifier being provided to a node selection input of said test point switch,

said RF receiver is further operable to (i) receive from said test point switch first upstream signals of said first test node, (ii) receive said third reverse telemetry signal, (iii) provide said controller with said first node identifier of said third reverse telemetry signal, and (iv) measure said first upstream signals received from said first test node to obtain a first plurality of measurement values for said first upstream signals,

said RF transmitter is further operable to transmit to said first field client via said CATV distribution network a second forward telemetry signal which includes said first plurality of measurement values,

said controller is further coupled to said test point switch and is further operable to cause said test point switch to electrically couple said first test node to said RF receiver by providing said first control signal indicative of said first node identifier to said node selection input, and

said first field client is further operable to (i) receive said second forward telemetry signal including said first plurality of measurement values, and (ii) display indicia of said first plurality of measurement values.

35. The CATV system of claim 34 wherein said RF receiver is further operable to obtain from said first upstream signals a separate measurement value for each frequency of a plurality of frequencies in order to obtain said first plurality of measurement values.

36. The CATV system of claim 34 wherein:

said RF transmitter is further operable to transmit said first node identifier as part of said second forward telemetry signal such that said first node identifier of said second forward telemetry signal associates said first plurality of measurement values of said second forward telemetry signal with said first test node; and

said first field client is further operable to (i) receive said second forward telemetry signal that further includes said first node identifier associated with said first plurality of measurement values, and (ii) determine from said first node identifier of said second forward telemetry signal that said first plurality of measurement values are associated with said first test node.