US5504606A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low power optical network unit
Assignee: AT&T Inc
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Filing: 1994-06-01
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Granted: 1996-04-02
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Expires: 2014-06-01
Abstract
Abstract An optical network unit for use in a switched passive optical network utilizes the high contrast ratio between the energies of optical ringing signals and optical interrogation signals. The receiver of the optical network unit is operated in a low power mode of operation until communication between the central office and subscriber is desired. In the low power mode, a photodetector runs in a photovoltaic mode to charge a sensing capacitor. An optical ringing signal originating in the central office when communication via the ONU is desired creates a voltage signal which is detected by a comparator circuit. When the comparator triggers, it switches on the receiver and directs the output of the photodiode to the receiver for processing of the communication signals received therefrom. On completion of the call, the ONU is returned to the low power state. When an off-hook signal is detected, the ONU interrupts the interrogation signals, thereby indicating to the central office that subscriber initiated communication via the ONU is desired.
Inventors
- 👤 Nicholas J. Frigo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:55
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/25; H04B10/2587; H04B10/80; H04B10/806; H04B10/807
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
151 words
An optical communication network unit for use in a switched network, said unit bring configured to receive optical signals including call request signals via an optical medium and to present information borne by said optical signals to at least one subscriber, comprising: light detecting means for detecting optical signals carried by the optical medium and for converting said optical signals into corresponding electrical signals; receiving means for receiving said electrical signals and for supplying the corresponding signals to the at least one subscriber; and control means responsive to said light detecting means and comprising a recognizing means coupled to said light detecting means and responsive to said call request signals, said control means causing power to be delivered to said receiving means to enable operating said receiving means in an operating mode upon receipt of said call request signals and for returning said receiving means to a low power quiescent mode.
Claim 2
Dependent Claim
151 words
An optical communication network unit for use in a switched network, said unit bring configured to receive optical signals including call request signals via an optical medium and to present information borne by said optical signals to at least one subscriber, comprising: light detecting means for detecting optical signals carried by the optical medium and for converting said optical signals into corresponding electrical signals; receiving means for receiving said electrical signals and for supplying the corresponding signals to the at least one subscriber; and control means responsive to said light detecting means and comprising a recognizing means coupled to said light detecting means and responsive to said call request signals, said control means causing power to be delivered to said receiving means to enable operating said receiving means in an operating mode upon receipt of said call request signals and for returning said receiving means to a low power quiescent mode.
Claim 3
Dependent Claim
15 words
The optical network unit of claim 1, wherein said light detecting means comprises a photodiode.
Claim 4
Dependent Claim
22 words
The optical network unit of claim 1, wherein said light detecting means is coupled to said receiver means during said operating mode.
Claim 5
Dependent Claim
62 words
The optical network unit of claim 1, wherein said recognizing means comprises a comparator operable during said quiescent mode to receive an output signal derived from said light detecting means indicative of light energy incident thereon and to compare said output signal to a reference signal level for recognizing a call request signal when said output signal exceeds said reference signal level.
Claim 6
Dependent Claim
54 words
The optical network unit of claim 4, wherein said reference signal is a reference voltage and said output signal is an output voltage, said control means being responsive to said comparator to supply power to said receiving means when said reference voltage is exceeded by said output voltage to thereby initiate said operating mode.
Claim 7
Dependent Claim
48 words
The optical network unit of claim 4, further comprising switching means for coupling said light detecting means to said receiving means to thereby initiate operation of the optical unit in the operating mode and for coupling said light detecting means to said recognizing means during the quiescent mode.
Claim 8
Dependent Claim
58 words
The optical network unit of claim 4, wherein said recognizing means further comprises a low pass filter coupled to an input of said comparator, said light detecting means being connectable across said low pass filter to permit charges corresponding to optical ringing signals incident on said light detecting means to accumulate until said reference signal level is exceeded.
Claim 9
Dependent Claim
37 words
The optical network unit of claim 7, further comprising dissipative means coupled to said light detecting means for substantially preventing charges corresponding to optical interrogating signals from causing said comparator to initiate operation of said control means.
Claim 10
Dependent Claim
24 words
The optical network unit of claim 8, wherein a light energy ratio between said ringing signals and said interrogating signals is greater than unity.
Claim 11
Dependent Claim
40 words
The optical network unit of claim 8, wherein said recognizing means is further operable to detect a telephone off-hook signal, said control means being responsive to said recognizing means to interrupt said interrogation signals upon detection of an off-hook signal.
Claim 12
Dependent Claim
49 words
The optical network unit of claim 1, further comprising a power supply for supplying power to said receiving means and switching means responsive to a control signal output from said control means for coupling said power supply to said receiving means to thereby enable operation of said receiving means.
Claim 13
Dependent Claim
13 words
The optical network unit of claim 1, wherein said optical signals are pulses.
Claim 14
Dependent Claim
18 words
The optical network unit of claim 1, wherein said light detecting means is operated as a current source.
Claim 15
Dependent Claim
18 words
The optical network unit of claim 1, wherein said light detecting means is operated as a voltage source.
Claim 16
Dependent Claim
164 words
A switched, passive network, comprising: a central office including means for supplying optical signals, including ringing and interrogating signals, to an optical medium; a remote node coupled to said optical medium for receiving said optical signals and directing selected signals to respective optical media; and at least one optical network unit, each of said optical network units being configured to receive said optical signals via one of said respective optical media and to present information corresponding to received signals to at least one subscriber, said optical network including: light detecting means for detecting optical signals carried by an associated optical medium and for converting said optical signals into corresponding electrical signals; receiving means for receiving said electrical signals and for supplying the corresponding signals to the at least one subscriber; and control means responsive to said light detecting means for supplying power to said receiving means in an operating mode and for interrupting power to said receiving means in a low power quiescent mode.
Claim 17
Dependent Claim
164 words
A switched, passive network, comprising: a central office including means for supplying optical signals, including ringing and interrogating signals, to an optical medium; a remote node coupled to said optical medium for receiving said optical signals and directing selected signals to respective optical media; and at least one optical network unit, each of said optical network units being configured to receive said optical signals via one of said respective optical media and to present information corresponding to received signals to at least one subscriber, said optical network including: light detecting means for detecting optical signals carried by an associated optical medium and for converting said optical signals into corresponding electrical signals; receiving means for receiving said electrical signals and for supplying the corresponding signals to the at least one subscriber; and control means responsive to said light detecting means for supplying power to said receiving means in an operating mode and for interrupting power to said receiving means in a low power quiescent mode.
Claim 18
Dependent Claim
41 words
The switched, passive network according to claim 15, said optical network unit further comprising recognizing means coupled to said light detecting recognizing means during said quiescent mode for recognizing receipt of a call request signal carried by said associated optical medium.
Claim 19
Dependent Claim
63 words
The switched, passive network according to claim 16, wherein said recognizing means comprises a comparator operable during said quiescent mode to receive an output signal derived from said light detecting means indicative of light energy incident thereon and to compare said output signal to a reference signal level for recognizing a call request signal when said output signal exceeds said reference signal level.
Claim 20
Dependent Claim
56 words
The switched, passive network according to claim 17, wherein said output signal is an output voltage and said reference signal level is a reference voltage, said control means being responsive to said comparator to supply power to said receiving means when said reference voltage is exceeded by said output voltage to thereby initiate said operating mode.
Claim 21
Dependent Claim
44 words
The switched, passive network according to claim 17, further comprising switching means for coupling said light detecting means to said receiving means to initiate operation in the operating mode and for coupling said light detecting means to said recognizing means during the quiescent mode.
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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) | 1999-04-02 | 1999-10-02 | 2000-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-02 | 2003-10-02 | 2004-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-02 | 2007-10-02 | 2008-04-02 | $7700.00 | Window Closed / Lapsed |