Cable drop monitor with upstream signalling

• US 7,568,207 B1
• Filed: 06/23/2000
• Issued: 07/28/2009
• Est. Priority Date: 06/23/2000
• Status: Expired due to Fees

• Current Assignee: Warren L. Braun
• Original Assignee: Warren L. Braun
• Inventors: Braun, Warren L.
• Primary Examiner(s): Miller, John W
• Assistant Examiner(s): CHOWDHURY, SUMAIYA A
• Application Number:
  US09/599,542
• Time in Patent Office: 3,322 Days
• Field of Search: 725106-107, 725118-121, 725127-130, 725/111, 725/125, 725/126, 725/25, 725/131, 725/15, 725/105, 725/143, 725/148, 725/149, 725/14, 725/16, 725/17, 725/9, 370241-248, 370305-307, 370/449, 370/359, 348180-182, 455/503
• US Class Current: 725/9
• CPC Class Codes: H04N 17/00 Diagnosis, testing or measuring for television systems or their details
• CPC Class Codes: H04N 21/44245 Monitoring the upstream path of the transmission network, e.g. its availability, bandwidth
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• 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
• CPC Class Codes: H04N 7/17354 in an intermediate station common to a plurality of user terminals

Abstract

A time slot is provided for each terminal unit or cable drop of a signal distribution system in a repeated sequence to communicate detected conditions “upstream”. The time slots are defined in accordance with a time base responsive to broadcast time signals. An identification of each terminal unit is transmitted from a directional coupler corresponding to the terminal unit or cable drop after latching an output of a condition detector responsive to detection of a condition by a sequence of tones or tone pairs, preferably using circuits ubiquitous in the telecommunications industry. A printer is provided for each channel at a central facility and the transmitting terminal unit is identified in response to another time base operating synchronously with the time base defining the time slots and assigning the time slots to respective terminal units. Provision is made for synchronization of counters, error checking and control of polling frequency.

Claims

1. A signal distribution system including

a communication path between a central facility including a signal source and a termination section including a plurality of cable drops,

a condition detector at respective ones of said plurality of cable drops,

means for providing a sequence of tones responsive to said condition detector,

means for coupling said sequence of tones to said communication path during a time slot associated with a said cable drop determined by a time base at said termination section of said communication path, and

means for decoding said sequence of tones at said central facility in accordance with respective time slots as determined by a time base at said central facility, said respective time slots as determined by said time base at said central facility including a time slot corresponding to said time slot as determined by said time base at said termination section of said communication path, said time base at said termination section and said time base at said central facility being independent of each other and responsive to a broadcast time signal, said broadcast time signal including a time indication signal for synchronization of corresponding time slots, wherein said termination section does not require any need for any interrogation downstream signaling or to independently broadcast a broadcast time signal from the central facility and vice-versa.

2. A system as recited in claim 1, wherein said means for providing said sequence of tones provides a sequence of tone pairs.

3. A system as recited in claim 2, wherein said means for decoding provides a digital signal input to a printer.

4. A system as recited in claim 1, wherein said condition detector detects at least one of power outage and ingress.

5. A system as recited in claim 1, wherein said system is divided into a plurality of sectors.

6. A system as recited in claim 1, wherein said time base is provided at a directional coupler providing communication links to a plurality of said cable drops.

7. A system as recited in claim 1, wherein said time base includes a counter for counting time slots.

8. A system as recited in claim 7, further including a comparator responsive to said counter for identifying time slots corresponding to respective ones of said plurality of cable drops.

9. A system as recited in claim 8, further including

means for latching an output of said condition detector and wherein said comparator is responsive to an output of said means for latching and said counter for controlling said means for generating said sequence of tones.

10. A system as recited in claim 1, further including

a time base at said central facility, and

means for counting time slots at said central facility.

11. A system as recited in claim 10, further including

means for comparing an output of said means for counting time slots at said central facility and an output of said means for decoding said sequence of tones.

12. A system as recited in claim 1, further including

means for controlling polling frequency of said cable drops.

13. A system as recited in claim 7, further including

means for resetting said counter.

14. A system as recited in claim 10, further including means for synchronizing said counter with said means for counting time slots at said central facility.

15. A system as recited in claim 1, further including

means for storing power for operation of said condition detector, said means for providing said sequence of tones and said means for coupling said sequence of tones to said communication link.

16. A system as recited in claim 1, wherein said means for coupling said sequence of tones to said communication link includes

means for modulating a carrier signal.

17. A system as recited in claim 16, wherein a frequency of said carrier signal is approximately 25 KHz.

18. A method of monitoring a plurality of terminal units of a system including the steps of

assigning a time slot of a plurality of sequential time slots to each terminal unit of a group of terminal units, said time slots being independently but synchronously defined at a termination section and a central station of said system responsive to a broadcast time signal including a time indication signal for synchronization of corresponding time slots at said termination section and said central facility, respectively, wherein said termination section does not require any need for any interrogation downstream signaling or to independently broadcast a broadcast time signal from the central facility and vice-versa,

selectively coupling a signal including a sequence of tones to a communication link of said system in a time slot corresponding to a terminal unit based on a detected condition, and

identifying a terminal unit in accordance with said sequence of tones at a central facility and synchronized with said time slots.

19. A method as recited in claim 18, including the further step of

printing indicia corresponding to said sequence of tones.

20. A method as recited in claim 18, including the further step of

transmitting a further tone corresponding to said detected condition.

21. A method as recited in claim 20, including the further step of

printing indicia corresponding to said further tone.

22. A method as recited in claim 18, including the further step of

storing power for performing said assigning and selectively coupling steps with electrical circuits.

23. A method as recited in claim 18, wherein said sequence of tones include a sequence of tone pairs.