Patent US5790523A successfully refreshed from Google Patents.
US5790523A
Expired / Lapsed
US
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Testing facility for a broadband communications system
Assignee: Cisco Technology Inc
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Filing: 1996-07-31
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Granted: 1998-08-04
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Expires: 2016-07-31
Abstract
Abstract A test system for evaluating the operating state of a headend of a broadband communications network for communicating telephony signals between a telephony system and subscribers of communications services. Modulators at the headend transmit telephony signals in the forward band of the broadband communications network. The forward telephony channels are demodulated and demultiplexed by a plurality of subscriber terminals into individual telephony signals directed to an addressed subscriber. Signals returning from subscribers are digitized into standard telephony signals onto the reverse band of the broadband communications network, and demodulated by demodulators of the headend into a standard telephony signal that is interfaced to the telephony network. The test system evaluates the operating state of a selected demodulator of the headend by modulating a carrier with a predetermined data pattern to generate a upstream test signal. The upstream test signal is transmitted to the selected demodulator, which responds by outputting a detected upstream test signal. The test system compares the detected upstream test signal to the data pattern to generate error measurements that support an evaluation of the operating state of the selected demodulator. For an ingress test, the upstream signals present on the selected upstream channel are combined with the upstream test signal, and this signal combination is analyzed to determine the status of the selected upstream channel and the selected demodulator. The test system evaluates the operating state of a selected modulator of the headend in response to receiving a downstream test signal generated by the selected modulator. The test system outputs a detected downstream test signal in response to the downstream test signal. In turn, the test system conducts error measurements in response to the detected downstream test signal that support an evaluation of the operating state of the selected modulator.
Inventors
- 👤 John A. Ritchie, Jr.
- 👤 Steve Idler
- 👤 Gregory T. Dubberly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:02
CPC Classifications
H; H04; H04H; H04H20/00; H04H20/12; H04H20/65; H04H20/76; H04H20/77; H04H20/78; H04H20/81; H04H60/00; H04H60/76; H04H60/81; H04H60/93; H04H60/96; H04H60/97; H04J; H04J1/00; H04J1/02; H04J1/12; H04J3/00; H04J3/16; H04J3/1605; H04J3/1623; H04L; H04L12/00; H04L12/28; H04L12/2801; H04M; H04M7/00; H04M7/006; H04N; H04N7/00; H04N7/10; H04N7/14; H04N7/16; H04N7/173; H04N7/17309; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04J2203/00; H04J2203/0001; H04J2203/0028; H04J2203/0039; H04J2203/0041; H04J2203/0089; H04L12/40; H04L12/407; H04L12/413; H04N2007/1739; H04Q2213/00; H04Q2213/13332
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
136 words
A telephony system for communicating telephony signals between a telephony network and subscribers to the telephony system, including a broadband communication network having a headend for communicating to the subscribers, the headend comprising: a modulator, coupled between the telephony network and the broadband communications network, for modulating the telephony signals from the telephony network on a carrier in a first band of the broadband communication network; channel assignment equipment for assigning telephony signals from one or more subscribers to a selected frequency subband in a second band of the broadband communication network; a demodulator, coupled between the telephony network and the broadband communications network, for demodulating the telephony signals in said selected frequency subband and coupling them to the telephony network; and a test system for evaluating the operating state of the modulator and the demodulator.
Claim 2
Dependent Claim
136 words
A telephony system for communicating telephony signals between a telephony network and subscribers to the telephony system, including a broadband communication network having a headend for communicating to the subscribers, the headend comprising: a modulator, coupled between the telephony network and the broadband communications network, for modulating the telephony signals from the telephony network on a carrier in a first band of the broadband communication network; channel assignment equipment for assigning telephony signals from one or more subscribers to a selected frequency subband in a second band of the broadband communication network; a demodulator, coupled between the telephony network and the broadband communications network, for demodulating the telephony signals in said selected frequency subband and coupling them to the telephony network; and a test system for evaluating the operating state of the modulator and the demodulator.
Claim 3
Dependent Claim
63 words
The system of claim 1, wherein the test system comprises: an upstream transmitter for transmitting an upstream test signal to the demodulator to evaluate the operating state of the demodulator; a downstream receiver for receiving a downstream test signal transmitted by the modulator to evaluate the operating state of the modulator; a test controller for controlling the upstream transmitter and the downstream receiver.
Claim 4
Dependent Claim
37 words
The system of claim 2, wherein the upstream transmitter comprises: a data pattern generator for generating a data pattern; and a test modulator for modulating a carrier with the data pattern to generate the upstream test signal.
Claim 5
Dependent Claim
44 words
The system of claim 3, wherein the demodulator outputs a detected upstream test signal to the test system in response to receiving the upstream test signal, and the test controller compares the detected upstream test signal to the data pattern to collect error measurements.
Claim 6
Dependent Claim
34 words
The system of claim 4, wherein the test controller forwards the error measurements to a controller, and the controller updates a database defining the operating state of the demodulator based on the error measurements.
Claim 7
Dependent Claim
46 words
The system of claim 5, wherein the downstream receiver outputs a detected downstream test signal to the test controller in response to receiving the downstream test signal, and the test controller forwards error measurements to the controller in response to analyzing the detected downstream test signal.
Claim 8
Dependent Claim
24 words
The system of claim 6, wherein the controller updates a database defining the operating state of the modulator in response to the error measurements.
Claim 9
Dependent Claim
33 words
The system of claim 1, wherein the test system is operative to conduct an upstream test by injecting an upstream test signal into the demodulator to evaluate the operating state of the demodulator.
Claim 10
Dependent Claim
50 words
The system of claim 8, wherein the test system is operative to conduct an upstream test by injecting an upstream test signal and the telephony signals in said selected frequency subband into the demodulator to evaluate the operating state of the demodulator and the status of said selected frequency subband.
Claim 11
Dependent Claim
34 words
The system of claim 1, wherein the test system is operative to conduct a downstream test by receiving a downstream test signal generated by the modulator to evaluate the operating state of the modulator.
Claim 12
Dependent Claim
54 words
The system of claim 2, wherein the upstream test signal comprises a carrier modulated by a known data pattern, and the test system generates test measurements in response to conducting the upstream test, the test measurements defining the results of comparing the known data pattern to the upstream test signal demodulated by the demodulator.
Claim 13
Dependent Claim
21 words
The system of claim 11, wherein the known data pattern is generated by a pattern generator connected to the upstream transmitter.
Claim 14
Dependent Claim
119 words
The system of claim 1, wherein the test system comprises: an upstream transmitter for transmitting an upstream test signal to the demodulator to evaluate the operating state of the demodulator; a downstream receiver for receiving a downstream test signal transmitted by the modulator to evaluate the operating state of the modulator; a test controller for controlling the upstream transmitter and the downstream receiver; and a coupler, characterized by a direct path connected between the broadband communication network and the demodulator and a coupled port connected to the upstream transmitter, for coupling the upstream test signal to the demodulator via the coupled port and passing the telephony signals in the selected frequency subband to the demodulator via the direct path.
Claim 15
Dependent Claim
44 words
The system of claim 13, wherein the modulator comprises a test output and a primary output, the primary output supporting distribution of the carrier in the first band of the broadband communication network, and the test output supporting distribution of the downstream test signal.
Claim 16
Dependent Claim
37 words
The system of claim 14, wherein the upstream transmitter comprises: a data pattern generator for generating a data pattern; and a test modulator for modulating a carrier with the data pattern to generate the upstream test signal.
Claim 17
Dependent Claim
61 words
The system of claim 1, wherein the broadband communication network includes a subscriber terminal for demodulating the telephony signals in the first band of broadband communication network and coupling them to the subscriber, and for modulating the telephony signals from the subscriber in the selected frequency subband in the second band of the broadband communication network for communication to the headend.
Claim 18
Dependent Claim
29 words
The system of claim 1, wherein the broadband communication network is a bidirectional network, and further comprising equipment for providing television program signals in said first band to subscribers.
Claim 19
Dependent Claim
59 words
The system of claim 1, wherein the broadband communications network further comprises: a frequency agile modulator located at the subscriber operative to change the frequency at which telephony signals are being communicated to the headend from a first frequency subband to a second frequency subband in response to a command received from the channel assignment equipment of the headend.
Claim 20
Dependent Claim
168 words
A test system for a telephony system for communicating telephony signals between a telephony network and subscribers to the telephony system, including a broadband communication network having a headend for communicating to the subscribers, the headend comprising a modulator, coupled between the telephony network and the broadband communications network, for modulating the telephony signals from the telephony network on a carrier in a first band of the broadband communication network, and a demodulator, coupled between the telephony network and the broadband communications network, for demodulating telephony signals from subscribers in a selected frequency subband in a second band of the broadband communications network and coupling them to the telephony network, the test system comprising: an upstream transmitter for transmitting an upstream test signal to the demodulator to evaluate the operating state of the demodulator; a downstream receiver for receiving a downstream test signal transmitted by the modulator to evaluate the operating state of the modulator; and a test controller for controlling the upstream transmitter and the downstream receiver.
Claim 21
Dependent Claim
168 words
A test system for a telephony system for communicating telephony signals between a telephony network and subscribers to the telephony system, including a broadband communication network having a headend for communicating to the subscribers, the headend comprising a modulator, coupled between the telephony network and the broadband communications network, for modulating the telephony signals from the telephony network on a carrier in a first band of the broadband communication network, and a demodulator, coupled between the telephony network and the broadband communications network, for demodulating telephony signals from subscribers in a selected frequency subband in a second band of the broadband communications network and coupling them to the telephony network, the test system comprising: an upstream transmitter for transmitting an upstream test signal to the demodulator to evaluate the operating state of the demodulator; a downstream receiver for receiving a downstream test signal transmitted by the modulator to evaluate the operating state of the modulator; and a test controller for controlling the upstream transmitter and the downstream receiver.
Claim 22
Dependent Claim
37 words
The system of claim 19, wherein the upstream transmitter comprises: a data pattern generator for generating a data pattern; and a test modulator for modulating a carrier with the data pattern to generate the upstream test signal.
Claim 23
Dependent Claim
44 words
The system of claim 20, wherein the demodulator outputs a detected upstream test signal to the test system in response to receiving the upstream test signal, and the test controller compares the detected upstream test signal to the data pattern to generate error measurements.
Claim 24
Dependent Claim
34 words
The system of claim 21, wherein the test controller forwards a error measurements to the controller, and the controller updates a database defining the operating state of the demodulator based on the error measurements.
Claim 25
Dependent Claim
46 words
The system of claim 22, wherein the downstream receiver outputs a detected downstream test signal to the test controller in response to receiving the downstream test signal, and the test controller forwards error measurements to the controller in response to analyzing the detected downstream test signal.
Claim 26
Dependent Claim
24 words
The system of claim 23, wherein the controller updates a database defining the operating state of the modulator in response to the error measurements.
Claim 27
Dependent Claim
54 words
The system of claim 19, wherein the upstream test signal comprises a carrier modulated by a known data pattern, and the test system generates test measurements in response to conducting the upstream test, the test measurements defining the results of comparing the known data pattern to the upstream test signal demodulated by the demodulator.
Claim 28
Dependent Claim
24 words
The system of claim 25, wherein the known data pattern is a PRBS pattern generated by a pattern generator connected to the upstream transmitter.
Claim 29
Dependent Claim
52 words
The systems of claim 20, wherein the upstream test signal is combined with the telephony signals from subscribers in a portion of the selected frequency subband of the second band to support an examination of the operating state of the demodulator and the status of the portion of the selected frequency subband.
Claim 30
Dependent Claim
187 words
For a telephony system for communicating telephony signals between a telephony network and subscribers to the telephony system, including a broadband communication network having a headend for communicating to the subscribers, the headend comprising a modulator, coupled between the telephony network and the broadband communications network, for modulating the telephony signals from the telephony network on a carrier in a first band of the broadband communication network, and a demodulator, coupled between the telephony network and the broadband communications network, for demodulating telephony signals from subscribers in a selected frequency subband in a second band of the broadband communications network and coupling them to the telephony network, a method for testing the operating state of the headend, comprising the steps: evaluating the operating state of the demodulator by: generating a data pattern; modulating a carrier with the data pattern to generate a upstream test signal; transmitting an upstream test signal to the demodulator; receiving a detected upstream test signal from the demodulator; comparing the detected upstream test signal to the data pattern to generate error measurements that support an evaluation of the operating state of the demodulator.
Claim 31
Dependent Claim
187 words
For a telephony system for communicating telephony signals between a telephony network and subscribers to the telephony system, including a broadband communication network having a headend for communicating to the subscribers, the headend comprising a modulator, coupled between the telephony network and the broadband communications network, for modulating the telephony signals from the telephony network on a carrier in a first band of the broadband communication network, and a demodulator, coupled between the telephony network and the broadband communications network, for demodulating telephony signals from subscribers in a selected frequency subband in a second band of the broadband communications network and coupling them to the telephony network, a method for testing the operating state of the headend, comprising the steps: evaluating the operating state of the demodulator by: generating a data pattern; modulating a carrier with the data pattern to generate a upstream test signal; transmitting an upstream test signal to the demodulator; receiving a detected upstream test signal from the demodulator; comparing the detected upstream test signal to the data pattern to generate error measurements that support an evaluation of the operating state of the demodulator.
Claim 32
Dependent Claim
26 words
The method of claim 28 further comprising the step of updating a database defining the present operating state of the demodulator based on the error measurements.
Claim 33
Dependent Claim
57 words
The method of claim 28, further comprising the step: evaluating the operating state of the modulator by: using the modulator to generate a downstream test signal; receiving the downstream test signal; outputting a detected downstream test signal in response to receiving the downstream test signal; and conducting error measurements in response to the detected downstream test signal.
Claim 34
Dependent Claim
27 words
The method of claim 30 further comprising the step of updating a database defining the present operating state of the modulator in response to the error measurements.
Claim 35
Dependent Claim
37 words
The method of claim 30, wherein the downstream test signal comprises a carrier modulated by a known data pattern, and the step of conducting test measurements comprises: comparing the known data pattern to the detected downstream signal.
Claim 36
Dependent Claim
239 words
For a telephony system for communicating telephony signals between a telephony network and subscribers to the telephony system, including a broadband communication network having a headend for communicating to the subscribers, the headend comprising a modulator, coupled between the telephony network and the broadband communications network, for modulating the telephony signals from the telephony network on a carrier in a first band of the broadband communication network, and a demodulator, coupled between the telephony network and the broadband communications network, for demodulating telephony signals from subscribers in a selected frequency subband in a second band of the broadband communications network and coupling them to the telephony network, a method for testing the operating state of the headend, comprising the steps: evaluating the operating state of the demodulator by: generating a predetermined data pattern; modulating a carrier with the predetermined data pattern to generate a upstream test signal; transmitting an upstream test signal to the demodulator; receiving a detected upstream test signal from the demodulator; and comparing the detected upstream test signal to the data pattern to generate error measurements that support an evaluation of the operating state of the demodulator; and evaluating the operating state of the modulator by: using the modulator to generate a downstream test signal; receiving the downstream test signal; outputting a detected downstream test signal in response to receiving the downstream test signal; and conducting error measurements in response to the detected downstream test signal.
Claim 37
Dependent Claim
239 words
For a telephony system for communicating telephony signals between a telephony network and subscribers to the telephony system, including a broadband communication network having a headend for communicating to the subscribers, the headend comprising a modulator, coupled between the telephony network and the broadband communications network, for modulating the telephony signals from the telephony network on a carrier in a first band of the broadband communication network, and a demodulator, coupled between the telephony network and the broadband communications network, for demodulating telephony signals from subscribers in a selected frequency subband in a second band of the broadband communications network and coupling them to the telephony network, a method for testing the operating state of the headend, comprising the steps: evaluating the operating state of the demodulator by: generating a predetermined data pattern; modulating a carrier with the predetermined data pattern to generate a upstream test signal; transmitting an upstream test signal to the demodulator; receiving a detected upstream test signal from the demodulator; and comparing the detected upstream test signal to the data pattern to generate error measurements that support an evaluation of the operating state of the demodulator; and evaluating the operating state of the modulator by: using the modulator to generate a downstream test signal; receiving the downstream test signal; outputting a detected downstream test signal in response to receiving the downstream test signal; and conducting error measurements in response to the detected downstream test signal.
Claim 38
Dependent Claim
44 words
The method of claim 33 further comprising the step of updating a database defining the present operating state of the demodulator based on the error measurements, and updating a database defining the present operating state of the modulator in response to the error measurements.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-03 | 2002-02-02 | 2002-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-03 | 2006-02-02 | 2006-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-03 | 2010-02-02 | 2010-08-04 | $7700.00 | Window Closed / Lapsed |