DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
Acknowledgment is made of applicant’s claim for foreign priority under 35 U.S.C. 119 (a)-(d). The certified copy has been filed in parent Application EP 23207182.9, filed on 31 October 2023.
Information Disclosure Statement
The listing of references in the specification is not a proper information disclosure statement. 37 CFR 1.98(b) requires a list of all patents, publications, or other information submitted for consideration by the Office, and MPEP § 609.04(a) states, "the list may not be incorporated into the specification but must be submitted in a separate paper." Therefore, unless the references have been cited by the examiner on form PTO-892, they have not been considered.
Claim Objections
Claims 8 and 19 are objected to because of the following informality: "afrequency" should read "a frequency". Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1, 9, and 11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claims 1, 9, and 11 recite the limitation "the transmission signal". There is insufficient antecedent basis for this limitation in the claim.
Claims 1, 9, and 11 encompass a broader scope than justified by the description and drawings. The description implies that the method of claims 1, 9, and 11 are performed in a coherent passive optical network (PON) wherein upstream and downstream signals are transported on the same fiber (Page 1, Lines 15-21 – “Coherent PON systems are at an early stage. A straightforward solution is the use of the upper and lower sidebands of the modulated light signal for upstream and downstream signals (or vice versa). While the frequency bands used for both directions are disjoint, any reflected part of the transmitted signal falls into the bandwidth of the coherent receiver, when the transmit laser is used as local oscillator, and saturate amplifiers and ADCs. The problem to be solved is to overcome this disadvantage.”). The metes and bounds of the claims are unclear because the claims do not specify the network configuration or relationship between the upstream and downstream signals that is necessary to give the claimed invention the scope contemplated by the description and drawings.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-5, 7, 9-16, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Zhou (USPUB 20190326995).
As per claims 1, 9, and 11,
Zhou teaches a method for processing optical signals, an optical transceiver (FIG. 1, Optical Hub 102, Downstream Tx 126, Upstream Rx 132), and a device for processing optical signals comprising a processing unit that is arranged to perform operations (Paragraph [0205] – "In some embodiments, the smart controller represents an advanced control device having improved communication, sensing, and control capabilities. The smart controller may, for example, include or be a server, a microprocessor, or an ASIC. The smart controller may further include a memory or EEPROM capable of storing detailed tables of slave laser or FP locking conditions with respect to the injected master laser optical power, and which may further include detailed information regarding relevant slave laser drive currents and junction temperatures."), comprising:
deriving both of a mixing signal and a transmission carrier from a single light source (FIG. 1, external laser 118, optical frequency comb generator 114, multiple coherent tones 120(1), 120(1′), . . . 120(N), 120(N′); Paragraph [0070] – "In operation, system 100 utilizes optical frequency comb generator 114 and amplifier 122 convert the input high quality source signal 116 into multiple coherent tones 120 (e.g., 32 tones, 64 tones, etc.)"),
wherein the mixing signal is located within the frequency band of a received signal and/or wherein the transmission carrier is located within the frequency band of the transmission signal (Paragraph [0071] – "the architecture of optical frequency comb generator 114 advantageously produces high quality continuous wave (CW) signals. Specifically, first unmodulated signal 168 (Ch1) may function as a downstream seed and upstream LO throughout system 100, while second unmodulated signal 170 (Ch1′) concurrently may function as an upstream seed and downstream LO for system 100."; Paragraph [0072] – "within optical hub 102, first unmodulated signal 168 (Ch1) is divided by hub optical splitter 130 and is separately input to both downstream transmitter 126 and upstream receiver 132 as a “pure” signal, and i.e., substantially low amplitude, narrow bandwidth continuous wave does not include adhered data. First unmodulated signal 168 (Ch1) thus becomes a seed signal for downstream transmitter 126 and an LO signal for upstream receiver 132.").
Zhou does not explicitly teach wherein the mixing signal is located within the frequency band of a received signal and/or wherein the transmission carrier is located within the frequency band of the transmission signal. However, one of ordinary skill in the art would recognize that the receiver uses the mixing signal as local oscillator for reception, such that the mixing signal is within the frequency band of the received signal for coherent detection. Similarly, the transmitter uses the carrier signal as seed for downstream modulation, such that the transmission carrier is located within the frequency band of the transmission signal.
As per claims 2 and 13, Zhou teaches claims 1 and 11.
Zhou teaches wherein the single light source comprises a laser or a laser diode (FIG. 1, external laser 118).
As per claims 3 and 14, Zhou teaches claims 1 and 11.
Zhou teaches wherein the method is operated by an optical transceiver, as well as a device further comprising an optical transceiver configured to perform the operations (FIG. 1, downstream transmitter 126 and upstream receiver 132).
As per claims 4 and 15, Zhou teaches claims 1 and 11.
Zhou teaches wherein the mixing signal corresponds to, or is based on, a local oscillator for receiving signals (Paragraph [0071] – "Specifically, first unmodulated signal 168 (Ch1) may function as a downstream seed and upstream LO throughout system 100, while second unmodulated signal 170 (Ch1′) concurrently may function as an upstream seed and downstream LO for system 100.").
As per claims 5 and 16, Zhou teaches claims 1 and 11.
Zhou teaches wherein the mixing signal and a transmission carrier are separated by a fixed frequency (Paragraph [0080] – "Optical frequency comb generator 114 produces a plurality of simultaneous narrow width wavelength channels with controlled spacing, thereby allowing simplified tuning of the entire wavelength comb. This centralized comb light source in optical hub 102 therefore provides master seeding sources and LO signals for both downstream and upstream directions in heterodyne detection configurations in order to reuse the optical sources throughout the entirety of system 100").
As per claims 7 and 18, Zhou teaches claims 1 and 11.
Zhou teaches wherein the frequency of the transmission carrier is adjusted based on an offset between the frequency of the mixing signal and a center frequency of the received signal (Paragraph [0138] – "homodyne detection unit 1418 is advantageously capable of achieving carrier recovery in the optical domain without any delay"). One of ordinary skill in the art would recognize that carrier recovery involves estimating and compensating for frequency and phase differences between a received signal's carrier wave and the receiver's local oscillator (mixing signal) for the purpose of coherent demodulation.
As per claim 10, Zhou teaches claim 9.
Zhou teaches wherein the transceiver is located in an optical network component, in particular in an OLT or an ONU (FIG. 1, Optical Hub 102, Downstream Tx 126, Upstream Rx 132; Paragraph [0064] – "FIG. 1 is a schematic illustration of an exemplary fiber communication system 100 in accordance with an exemplary embodiment of the present disclosure. System 100 includes an optical hub 102, a fiber node 104, and an end user 106. Optical hub 102 is, for example, a central office, a communications hub, or an optical line terminal (OLT).").
As per claim 12, Zhou teaches claim 11.
Zhou teaches wherein the device is, or is part of, an optical line terminal or an optical network unit (FIG. 1, optical hub 102, end user 106; Paragraph [0064] – "System 100 includes an optical hub 102, a fiber node 104, and an end user 106. Optical hub 102 is, for example, a central office, a communications hub, or an optical line terminal (OLT). In the embodiment shown, fiber node 104 is illustrated for use with a passive optical network (PON). End user 106 is a downstream termination unit, which can represent, for example, a customer device, customer premises (e.g., an apartment building), a business user, or an optical network unit (ONU).").
Claims 1-4, 6-7, 9-15, and 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Olson (USPAT 10972184).
As per claims 1, 9, and 11,
Olson teaches a method for processing optical signals, an optical transceiver (FIG. 1, Transceivers 110 and 120), and a device for processing optical signals comprising a processing unit that is arranged to perform operations (FIG. 3, TX DSP 902) comprising:
deriving both of a mixing signal and a transmission carrier from a single light source (FIG. 1, laser 111, splitter 112, transmitter 113, receiver 114; Col. 9, Lines 43-56 – "The first transceiver 110 includes a laser 111, a splitter 112, a transmitter 113, a receiver 114, and a circulator 115. The laser 111 is communicatively coupled (for example, via an optical fiber) and is configured to generate and provide an optical signal, such as a continuous wave (CW) optical signal. The splitter 112 is communicatively coupled to the transmitter 113 and the receiver 114. In the illustrated example, the splitter 122 is configured to receive the optical signal generated by laser 111 and split the signal into two portions. The splitter 112 is configured to provide the first portion of the signal to the transmitter 113 and the second portion to the receiver 114. The second portion of the signal can be used at the receiver 114, for example, as a local oscillator signal."),
wherein the mixing signal is located within the frequency band of a received signal and/or wherein the transmission carrier is located within the frequency band of the transmission signal (Col. 9, Lines 50-56 – "the splitter 122 is configured to receive the optical signal generated by laser 111 and split the signal into two portions. The splitter 112 is configured to provide the first portion of the signal to the transmitter 113 and the second portion to the receiver 114. The second portion of the signal can be used at the receiver 114, for example, as a local oscillator signal.").
Olson does not explicitly teach wherein the mixing signal is located within the frequency band of a received signal and/or wherein the transmission carrier is located within the frequency band of the transmission signal. However, one of ordinary skill in the art would recognize that the receiver can use the mixing signal (the second portion of the signal) as a local oscillator signal, such that the mixing signal is within the frequency band of the received signal.
As per claims 2 and 13, Olson teaches claims 1 and 11.
Olson teaches wherein the single light source comprises a laser or a laser diode (FIG. 1, laser 111).
As per claims 3 and 14, Olson teaches claims 1 and 11.
Olson teaches wherein the method is operated by an optical transceiver, as well as a device further comprising an optical transceiver configured to perform the operations (FIG. 1, Transceivers 110 and 120).
As per claims 4 and 15, Olson teaches claims 1 and 11.
Olson teaches wherein the mixing signal corresponds to, or is based on, a local oscillator for receiving signals (Col. 2, Lines 9-18 – "The receiver includes a photodiode circuit and a second DSP circuit. The photodiode circuit includes at least one photodiode to receive first optical mixing products or second optical mixing products, the first optical mixing products being based on a third plurality of optical subcarriers received from the optical fiber via the optical port and a local oscillator signal, and the second optical mixing products being based on a fourth plurality of optical subcarriers received from the optical fiber via the optical port and the local oscillator signal.").
As per claims 6 and 17, Olson teaches claims 1 and 11.
Olson teaches filtering of a signal to separate a useful signal from a reflected signal and an impairment signal (FIG. 8, CDEQ circuits 1212-1-1 to 1212-1-8, PMDEQ circuits 1225-1 to 1225-8; Col. 7, Lines 3-65 – "FIG. 8 is a diagram illustrating an example of a DSP circuit included in the receiver of FIG. 7, in accordance with one or more implementations of the present disclosure."; Col. 18, Lines 24-29 – "each of CDEQ circuits 1212-2-1 to 1212-2-8 can include an FIR filter that corrects, offsets, or reduces the effects of, or errors associated with chromatic dispersion of the transmitted optical subcarriers. In addition, each of CDEQ circuits 1212-2-1 to 1212-2-8 provide an output to a corresponding one of PMDEQ circuits 1225-1 to 1225-8."; Col. 21, Lines 49-55 – "Each of the plurality of receivers Rx-1 to Rx-m can include the receiver 1100 described previously, and therefore can receive a number of subcarriers from the ONUs and dynamically block output of data associated with at least some of the received number of subcarriers, as well as spurious electrical signal associated with back-reflected light generated by downlink subcarriers.").
One of ordinary skill in the art would recognize that blocking a spurious electrical signal associated with back-reflected light generated by downlink subcarriers would require a low pass filter due to the slight increase in wavelength from reflection.
Additionally, one of ordinary skill in the art would recognize that implementing a low pass filter in the electrical domain rather than the optical or digital domain would still have led to an easily predictable outcome of isolating the useful signal from the reflected and impairment signals.
As per claims 7 and 18, Olson teaches claims 1 and 11.
Olson teaches wherein the frequency of the transmission carrier is adjusted based on an offset between the frequency of the mixing signal and a center frequency of the received signal (Col. 18, Lines 47-60 – "Time domain signals or data output from IFFT 1230-1-1 to 1230-8-1 are supplied to a corresponding one of Xpol carrier phase correction circuits 1240-1-1 to 1240-8-1, which can apply carrier recovery techniques to compensate for X polarization transmitter (for example, laser 908) and receiver (e.g., local oscillator laser 1110) linewidths. In some implementations, each carrier phase correction circuit 1240-1-1 to 1240-8-1 can compensate or correct for frequency and/or phase differences between the X polarization of the transmit signal and the X polarization of light from the local oscillator 1100 based on an output of Xpol carrier recovery circuit 1240-8-1, which performs carrier recovery in connection with one of the subcarrier based on the outputs of IFFT 1230-8-1.").
As per claim 10, Olson teaches claim 9.
Olson teaches wherein the transceiver is located in an optical network component, in particular in an OLT or an ONU (FIG. 12, OLT 1310, ONUs 1350-1 to 1350-n; Col. 20, Line 64 to Col. 21, Line 18 – "FIG. 12 is a diagram illustrating an example of a point-to-multi-point bidirectional communications system 1300, in accordance with one or more implementations of the present disclosure. The system 1300 includes an optical line terminal (OLT) 1310 and multiple optical network units (ONUs), including ONU 1350-1, 1350-2 to 1350-n. The OLT 1310 is communicatively coupled to each of the plurality of ONUs 1350-1 to 1350-n via a bidirectional optical link 1330. The bidirectional optical link 1330 uses a splitter/combiner 1340 to facilitate communications between the OLT 1310 and each of the ONUs 1350-1-1350-n. The OLT 1310 includes a plurality of transmitters Tx-1 to Tx-m and a plurality of receivers Rx-1 to Rx-m. Each of the plurality of transmitters Tx-1 to Tx-m and the plurality of receivers Rx-1 to Rx-m can be dedicated, respectively, to a particular channel of a plurality of channels, in which each channel is further dedicated to one of the ONUs 1350-1 to 1350-n, or one or more channels may be split or divided between multiple ONUs, such that multiple ONU transmit and receive optical subcarriers associated with the same channel.").
As per claim 12, Olson teaches claim 11.
Olson teaches wherein the device is, or is part of, an optical line terminal or an optical network unit (FIG. 12, OLT 1310, ONUs 1350-1 to 1350-n; Col. 20, Line 64 to Col. 21, Line 8 – "FIG. 12 is a diagram illustrating an example of a point-to-multi-point bidirectional communications system 1300, in accordance with one or more implementations of the present disclosure. The system 1300 includes an optical line terminal (OLT) 1310 and multiple optical network units (ONUs), including ONU 1350-1, 1350-2 to 1350-n. The OLT 1310 is communicatively coupled to each of the plurality of ONUs 1350-1 to 1350-n via a bidirectional optical link 1330. The bidirectional optical link 1330 uses a splitter/combiner 1340 to facilitate communications between the OLT 1310 and each of the ONUs 1350-1-1350-n.").
Claims 8 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Zhou (USPUB 20190326995) as applied to claims 1 and 11 above, and further in view of Eiselt (EP 3786689) and Yamazaki in the article 'Dual-carrier IQ modulator with a complementary frequency shifter'.
As per claims 8 and 19, Zhou teaches claims 1 and 11.
Zhou does not teach obtaining a frequency shift by a phase slope modulation over time.
However, in an analogous art, Eiselt teaches a phase modulator which can apply a linear phase modulation to the output signal of a single-frequency laser (Paragraph [0001] – "The invention relates to an optical endless phase shifting device configured to shift an optical input signal by a desired phase shift as well as to a method therefore"). One of ordinary skill in the art would recognize that this results in a frequency-shifted carrier signal.
It would have been obvious for one of ordinary skill in the art at the effective filing date of the claimed invention to combine the teachings of Eiselt with the teachings of Zhou in order to utilize the output signal of a laser as a transmission carrier.
Although the combination of Zhou and Eiselt does not teach determining the frequency shift using the transmission carrier, it would be obvious to one of ordinary skill in the art to utilize the frequency of the single light source and the transmission carrier to determine the frequency shift.
Eiselt teaches generating the mixing signal and the transmission carrier by modulation through a signal with a frequency amounting to a frequency shift Δf or a sub-harmonic thereof (Paragraph [0001] – "The invention relates to an optical endless phase shifting device configured to shift an optical input signal by a desired phase shift as well as to a method therefore"). The transmission carrier can be obtained by applying a desired phase shift to the mixing signal (local oscillator signal) or vice versa.
It would have been obvious for one of ordinary skill in the art at the effective filing date of the claimed invention to combine the teachings of Eiselt with the teachings of Zhou in order to generate the mixing signal using the transmission carrier, or vice versa.
Neither Zhou nor Eiselt teaches obtaining the mixing signal and the transmission carrier via an I-Q-modulator utilizing a phase-slope modulation corresponding to half the desired frequency shift value.
However, in an analogous art, Yamazaki teaches the use of an I-Q-modulator (Page 1, Abstract – "We devised a dual-carrier IQ modulator consisting of a novel complementary frequency shifter (CFS) and two IQ modulators. The CFS generates two optical subcarriers from a single light source and outputs them from separate ports without using any optical demultiplexing filters."; Page 3, Section 4. Characteristics of the CFS – "Figure 4(a) shows the change in the peak frequency of the two outputs when we changed fs. The peak frequencies change proportionally to fs in opposite directions, and the frequency spacing, which corresponds to the horizontal split between the two lines, is always equal to 2fs."). In light of these teachings, one of ordinary skill in the art would have been motivated to implement the teachings of Yamazaki while utilizing a phase-slope modulation corresponding to half the desired frequency shift value.
Therefore, it would have been obvious to one of ordinary skill in the art to combine the teachings of Zhou with the teachings of Yamazaki to generate the transmission carrier.
Zhou teaches obtaining the mixing signal and the transmission carrier via a comb laser structure (Paragraph [0071] – "the architecture of optical frequency comb generator 114 advantageously produces high quality continuous wave (CW) signals. Specifically, first unmodulated signal 168 (Ch1) may function as a downstream seed and upstream LO throughout system 100, while second unmodulated signal 170 (Ch1′) concurrently may function as an upstream seed and downstream LO for system 100."; Paragraph [0072] – "within optical hub 102, first unmodulated signal 168 (Ch1) is divided by hub optical splitter 130 and is separately input to both downstream transmitter 126 and upstream receiver 132 as a “pure” signal, and i.e., substantially low amplitude, narrow bandwidth continuous wave does not include adhered data. First unmodulated signal 168 (Ch1) thus becomes a seed signal for downstream transmitter 126 and an LO signal for upstream receiver 132.").
It is noted that any citations to specific pages, columns, lines, or figures in the prior art references and any interpretation of the reference should not be considered to be limiting in any way. A reference is relevant for all it contains and may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art. See MPEP §2123.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Cano, Ivan, et al. "Bidirectional coherent PON with ONU based on reused direct-modulated LO." 2016 Optical Fiber Communications Conference and Exhibition (OFC). IEEE, 2016.
Chang, Lin, Songtao Liu, and John E. Bowers. "Integrated optical frequency comb technologies." Nature Photonics 16.2 (2022): 95-108.
Erkılınç, M. S., et al. "Bidirectional wavelength-division multiplexing transmission over installed fibre using a simplified optical coherent access transceiver." Nature communications 8.1 (2017): 1043.
Li, Jie, et al. "Real-time bidirectional coherent ultra-dense TWDM-PON for 1000 ONUs." Optics express 26.18 (2018): 22976-22984.
Presi, Marco, et al. "Single feeder bidirectional WDM-PON with enhanced resilience to Rayleigh-backscattering." 2010 Conference on Optical Fiber Communication (OFC/NFOEC), collocated National Fiber Optic Engineers Conference. IEEE, 2010.
Galli (US 20220094374 A1)
Xu (USPAT 11349592)
Zhou (WO 2014040272)
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JACOB ETHAN DELA ROSA-FRIO whose telephone number is (571) 270-5776. The examiner can normally be reached Monday - Friday, 09:00 - 17:00 EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, David C Payne can be reached at (571) 272-3024. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JACOB ETHAN DELA ROSA-FRIO/Examiner, Art Unit 2635
/OMAR S ISMAIL/Primary Examiner, Art Unit 2635
Prosecution Insights