Patent US6239892B1 successfully refreshed from Google Patents.
US6239892B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for bit synchronization in optical communication and networking systems
Assignee: Oracle America Inc
•
Filing: 1998-05-31
•
Granted: 2001-05-29
•
Expires: 2018-05-31
Abstract
Abstract An apparatus and method are provided for bit synchronization in an optical time division multiplexed communication system. The apparatus is couplable to an optical gate, such as an optical demultiplexer. The apparatus includes a programmable optical delay line couplable to an input clock; an optical synchronizer coupled to the programmable optical delay line and couplable to the optical gate; and a processor coupled to the programmable optical delay line and to the optical synchronizer. The processor includes program instructions to track bit synchronization between a clock pulse and a selected data bit during a communication session; and when a bit tracking range is approaching a predetermined limit, the processor having further instructions to interrupt the communication session, return the bit tracking range to a zero offset and correspondingly adjust a programmable delay, and resume the communication session.
Inventors
- 👤 Howard L. Davidson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:11
CPC Classifications
H; H04; H04L; H04L7/00; H04L7/02; H04L7/0075; H04L7/0016; H04L7/0033; H04L7/0037; H04J; H04J14/00; H04J14/08; H04L7/04; H04L7/10
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
72 words
A method of bit synchronization in an optical time division multiplexed communication system, the method comprising: (a) tracking bit synchronization between a clock pulse and a selected data bit during a communication session; and (b) when a bit tracking range is approaching a predetermined limit, interrupting the communication session, returning the bit tracking range to a zero offset and correspondingly adjusting timing of a programmable optical delay, and resuming the communication session.
Claim 2
Independent Claim
72 words
A method of bit synchronization in an optical time division multiplexed communication system, the method comprising: (a) tracking bit synchronization between a clock pulse and a selected data bit during a communication session; and (b) when a bit tracking range is approaching a predetermined limit, interrupting the communication session, returning the bit tracking range to a zero offset and correspondingly adjusting timing of a programmable optical delay, and resuming the communication session.
Claim 3
Dependent Claim
25 words
The method of claim 1 , further comprising: (c) when the communication session has been completed, returning the bit tracking range to a zero offset.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein the bit tracking range spans a plurality of bit periods.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein step (a) further comprises: incrementally accelerating clock pulse timing.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein step (a) further comprises: incrementally delaying clock pulse timing.
Claim 7
Dependent Claim
45 words
The method of claim 1 wherein step (a) further comprises: determining a timing difference between the clock pulse and the selected data bit; generating an error signal proportional to the timing difference; and adjusting timing of the clock pulse until the error signal approaches zero.
Claim 8
Dependent Claim
45 words
The method of claim 6 wherein the step of determining a timing difference further comprises: determining an amplitude error by comparing a known reference oscillation with a signal generated by low pass filtering and envelope detecting an output data signal having a dither signal component.
Claim 9
Dependent Claim
51 words
The method of claim 1 wherein step (b) further comprises: determining the bit tracking range; when the bit tracking range approaches a predetermined limit, terminating the communication session; decrementing the bit tracking range to a zero offset and correspondingly incrementing timing of the programmable optical delay; and reestablishing the communication session.
Claim 10
Dependent Claim
51 words
The method of claim 1 wherein step (b) further comprises: determining the bit tracking range; when the bit tracking range approaches a predetermined limit, terminating the communication session; incrementing the bit tracking range to a zero offset and correspondingly decrementing timing of the programmable optical delay; and reestablishing the communication session.
Claim 11
Dependent Claim
40 words
The method of claim 1 wherein tracking bit synchronization of step (a) further includes adjusting a relative spacing between a first collimating lens coupled to a first optical line and a second collimating lens coupled to a second optical line.
Claim 12
Independent Claim
149 words
An apparatus for bit synchronization in an optical time division multiplexed communication system, the apparatus couplable to an optical gate, the optical gate couplable to an input data signal, the optical gate providing an output data signal, the apparatus comprising: a programmable optical delay line couplable to an input clock; an optical synchronizer coupled to the programmable optical delay line and couplable to the optical gate; and a processor coupled to the programmable optical delay line and to the optical synchronizer, wherein the processor includes program instructions to track bit synchronization between a clock pulse and a selected data bit during a communication session; and when a bit tracking range is approaching a predetermined limit, the processor having further instructions to interrupt the communication session, return the bit tracking range to a zero offset and correspondingly adjust timing of the programmable optical delay line, and resume the communication session.
Claim 13
Independent Claim
149 words
An apparatus for bit synchronization in an optical time division multiplexed communication system, the apparatus couplable to an optical gate, the optical gate couplable to an input data signal, the optical gate providing an output data signal, the apparatus comprising: a programmable optical delay line couplable to an input clock; an optical synchronizer coupled to the programmable optical delay line and couplable to the optical gate; and a processor coupled to the programmable optical delay line and to the optical synchronizer, wherein the processor includes program instructions to track bit synchronization between a clock pulse and a selected data bit during a communication session; and when a bit tracking range is approaching a predetermined limit, the processor having further instructions to interrupt the communication session, return the bit tracking range to a zero offset and correspondingly adjust timing of the programmable optical delay line, and resume the communication session.
Claim 14
Dependent Claim
29 words
The apparatus of claim 11 wherein the processor includes further program instructions to return the bit tracking range to a zero offset when the communication session has been completed.
Claim 15
Dependent Claim
16 words
The apparatus of claim 11 wherein the bit tracking range spans a plurality of bit periods.
Claim 16
Dependent Claim
18 words
The apparatus of claim 11 wherein the processor includes further program instructions to incrementally accelerate clock pulse timing.
Claim 17
Dependent Claim
18 words
The apparatus of claim 11 wherein the processor includes further program instructions to incrementally delay clock pulse timing.
Claim 18
Dependent Claim
51 words
The apparatus of claim 11 wherein the processor includes further program instructions to determine a timing difference between the clock pulse and the selected data bit; to generate an error signal proportional to the timing difference; and to adjust a timing of the clock pulse until the error signal approaches zero.
Claim 19
Dependent Claim
48 words
The apparatus of claim 16 wherein the processor includes further program instructions to determine the timing difference by determining an amplitude error through comparing a known reference oscillation with a signal generated by low pass filtering and envelope detecting the output data signal having a dither signal component.
Claim 20
Dependent Claim
63 words
The apparatus of claim 11 wherein the processor includes further program instructions to determine the bit tracking range; and when the bit tracking range approaches the predetermined limit, the processor including further instructions to terminate the communication session, decrement the bit tracking range to a zero offset and correspondingly increment the timing of the programmable optical delay line, and reestablish the communication session.
Claim 21
Dependent Claim
63 words
The apparatus of claim 11 wherein the processor includes further program instructions to determine the bit tracking range; and when the bit tracking range approaches the predetermined limit, the processor including further instructions to terminate the communication session, increment the bit tracking range to a zero offset and correspondingly decrement the timing of the programmable optical delay line, and reestablish the communication session.
Claim 22
Dependent Claim
48 words
The apparatus of claim 11 wherein the optical synchronizer further comprises: a first collimating lens coupled to a first optical line; a second collimating lens coupled to a second optical line; and means to adjust a relative spacing between the first collimating lens and the second collimating lens.
Claim 23
Dependent Claim
19 words
The apparatus of claim 20 wherein the relative spacing is directly proportional to a voltage signal from the processor.
Claim 24
Dependent Claim
20 words
The apparatus of claim 20 wherein the relative spacing is directly proportional to an amplified drive current from the processor.
Claim 25
Dependent Claim
27 words
The apparatus of claim 20 wherein the means to adjust the relative spacing between the first collimating lens and the second collimating lens includes a voice coil.
Claim 26
Dependent Claim
27 words
The apparatus of claim 20 wherein the means to adjust the relative spacing between the first collimating lens and the second collimating lens includes a piezo-ceramic actuator.
Claim 27
Dependent Claim
27 words
The apparatus of claim 20 wherein the means to adjust the relative spacing between the first collimating lens and the second collimating lens includes a tuning fork.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-05-28 | 2004-11-27 | 2005-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-05-28 | 2008-11-27 | 2009-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-05-28 | 2012-11-27 | 2013-05-29 | $7700.00 | Window Closed / Lapsed |