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 .
DETAILED OFFICE ACTION
Claim Status
Claims 1 and 2 are pending in this application and are under examination in this Office Action. No claims have been allowed.
Claim Rejections – 35 U.S.C. § 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.
Claims 1-2 are rejected under 35 U.S.C. § 112(b) (or, for pre-AIA applications, 35 U.S.C. § 112, second paragraph) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Regarding Claim 1:
Claim 1 is indefinite for at least the following reasons:
(A) Indefinite “center” requirement
Claim 1 recites: “changing the second frequency to be spectrally in a center of the spectral gap.”
The phrase “spectrally in a center” is indefinite because the claim does not define what reference points determine the “center.” For example, it is unclear whether the “center” is:
the midpoint between two center frequencies, or
the midpoint between spectral edges (which depends on how “spectral width” is measured), or
some other reference.
Without an objective definition of the spectral-gap boundaries, the claimed “center” is not reasonably certain.
(B) Indefinite definition of the “spectral gap” boundary in view of occupied bandwidth
Claim 1 recites that the second frequency is “in a spectral gap defined by” a first one of the plurality of first frequencies and a second one of the plurality of first frequencies, while also reciting that the first optical subcarriers each have a “first spectral width.”
Thus, it is unclear whether the “spectral gap” is intended to be:
the separation between two center frequencies (which may still include occupied spectrum depending on spectral width), or
the separation between two spectral edges of adjacent subcarriers (which depends on how spectral width is defined/measured).
Because the claim does not clearly identify whether the “spectral gap” is bounded by center frequencies or spectral edges, the metes and bounds of the “spectral gap” are not reasonably certain.
(C) Indefinite “spectral width” metric (less than / equal to)
Claim 1 recites “first spectral width,” “second spectral width … less than,” and later “equal to.” However, the claim does not specify the objective basis for measuring “spectral width” (e.g., 3-dB bandwidth, full-width at half-maximum, occupied bandwidth under a defined power mask/percentage, null-to-null bandwidth, etc.). Without reciting an objective measurement definition and conditions, it is not reasonably certain when one spectral width is “less than” or “equal to” another.
Accordingly, claim 1 is indefinite and is rejected under 35 U.S.C. § 112(b).
Regarding Claim 2:
Claim 2 is indefinite for at least the following reasons:
(A) Indefinite definition of the “spectral gap” boundary (mixed “frequency” vs. “subcarrier” + antecedent issue)
Claim 2 recites (emphasis added):“…each of the plurality of second frequencies being within a spectral gap defined by a first one of the plurality of first frequencies and a second one of the first plurality of subcarriers …”.
This language is indefinite because the “spectral gap” is defined by:
a frequency on one side (“a first one of the plurality of first frequencies”), and
a subcarrier on the other side (“a second one of the first plurality of subcarriers”).
A “subcarrier” is not itself a frequency, and the claim does not specify whether the boundary is the subcarrier’s center frequency, its spectral edge, or another reference. Additionally, “the first plurality of subcarriers” lacks clear antecedent basis in claim 2 (which previously introduces “a plurality of first optical subcarriers” and “a plurality of first frequencies”). Accordingly, the bounds of the recited “spectral gap,” and therefore whether the plurality of second frequencies are “within” that gap, are not reasonably certain.
(B) Lack of clear antecedent / inconsistent terminology
Claim 2 uses inconsistent phrasing and unclear antecedent basis (e.g., “second one of the first plurality of subcarriers” versus “second one of the plurality of first frequencies”), which renders the scope of the “spectral gap” and the relationships among the recited frequencies/subcarriers unclear.
(C) Indefinite phrase “each of the third plurality of frequencies begin within the spectral gap”
Claim 2 further recites (emphasis added):“…adding a plurality of third optical subcarriers… each… having… a plurality of third frequencies, each of the third plurality of frequencies begin within the spectral gap.”
This is indefinite because the phrase “frequencies begin within” is grammatically and technically unclear. A frequency value does not have a “beginning,” and the claim does not clarify whether “begin” refers to a center frequency, a lowest/starting spectral edge, or a frequency range.
As written, claim 2 fails to particularly point out and distinctly claim the invention. Therefore, claim 2 is indefinite and is rejected under 35 U.S.C. § 112(b).
Claim Rejections – 35 U.S.C. § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for the 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), and applied for determining obviousness under 35 U.S.C. § 103, are summarized as follows:
Determining the scope and content of the prior art;
Ascertaining the differences between the prior art and the claims at issue;
Resolving the level of ordinary skill in the pertinent art; and
Considering objective evidence indicative of obviousness or non-obviousness, if present.
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 C.F.R. § 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.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Rahn (US 10,992,389 B2) in view of Zhou (“Enabling technologies and challenges for transmission of 400 Gb/s signals in 50 GHz channel grid”).
Claim 1 recites, in substance, transmitting first optical subcarriers at first frequencies with a first spectral width; transmitting a second optical subcarrier having a second frequency within a spectral gap between two first frequencies and having a smaller spectral width; changing the second frequency to be at a center of the spectral gap; and then enlarging the second spectral width to equal the first spectral width.
Re: transmitting a plurality of first optical subcarriers.Rahn teaches outputting a modulated optical signal including multiple subcarriers, i.e., “output a modulated optical signal including a plurality of optical subcarriers.” (Rahn, col. 34, ll. 1–6).
Re: each first subcarrier having a respective first frequency.Rahn teaches multiple subcarriers each at a respective frequency, e.g., “optical subcarriers SC1 to SC4 having frequencies f1 to f4.” (Rahn, col. 16, ll. 18–22).
Re: each first subcarrier having a first spectral width.Rahn teaches shaping subcarriers to control occupied bandwidth via roll-off, including that “the roll-off factor can be assigned to be very narrow … while one subcarrier is given a wider roll-off factor.” (Rahn, col. 15, ll. 1–8).Rahn further teaches bandwidth as a property of subcarriers, e.g., “the first subcarrier has a first frequency bandwidth … [and] the second subcarrier has a second frequency bandwidth different ….” (Rahn, col. 31, ll. 55–63).
Re: transmitting a second optical subcarrier having (i) a second frequency within a spectral gap between two first frequencies and (ii) a second spectral width less than the first spectral width.Rahn teaches frequency gaps between subcarriers, including “associated frequency gaps G1-1 to G1-3” between subcarriers. (Rahn, col. 16, ll. 18–24).Rahn also teaches that subcarrier frequency assignments and spacings are configurable, i.e., “[subcarrier frequencies] may be set to result in particular frequency assignments and spacings ….” (Rahn, col. 16, ll. 1–4).Further, Rahn teaches controlling spectral width/occupied bandwidth via roll-off (narrow vs. wider), which would have allowed the second subcarrier to initially be shaped narrower to fit within an available gap. (Rahn, col. 15, ll. 1–8).
Accordingly, it would have been obvious to one of ordinary skill in the art to transmit a second optical subcarrier with a second frequency within a selected spectral gap and to initially shape it with a smaller occupied bandwidth (i.e., smaller “spectral width”) to reduce interference and fit the available spectrum.
Re: changing the second frequency to be spectrally in a center of the spectral gap.Zhou teaches tuning a carrier to the center of a channel, i.e., “the carrier frequency is tuned to the center of the channel.” (Zhou, p. 33 (PDF p. 5)).Thus, it would have been obvious to apply Zhou’s feedback-based tuning to tune the second subcarrier frequency to a desired center location (center of the selected spectral gap) for improved alignment/robustness.
Re: enlarging the second spectral width after changing the second frequency such that it equals the first spectral width.Rahn teaches changing roll-off to control bandwidth (narrow vs. wider) (Rahn, col. 15, ll. 1–8) and teaches bandwidth differences/relationships across subcarriers (Rahn, col. 31, ll. 55–63).Accordingly, after centering/tuning the second subcarrier as taught by Zhou, it would have been obvious to widen the second subcarrier’s occupied bandwidth (increase “spectral width”) to match a desired baseline width (equalize widths) to improve spectral efficiency while maintaining a controlled spacing strategy.
One of ordinary skill in the art would have been motivated to combine Rahn with Zhou because Rahn provides a multi-subcarrier transmitter with configurable spacing and bandwidth shaping, while Zhou teaches practical feedback-based tuning to a channel center to improve performance and robustness. Therefore, claim 1 would have been obvious.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Rahn in view of Zhou and further in view of Zhang (“Spectrum Defragmentation Algorithms for Elastic Optical Networks using Hitless Spectrum Retuning Techniques,” OFC).
Claim 2 recites, in substance, transmitting first subcarriers at first frequencies; transmitting multiple second subcarriers at second frequencies located within a spectral gap; changing the second frequencies; and adding third subcarriers whose third frequencies begin within the spectral gap.
Re: transmitting a plurality of first optical subcarriers each having a respective first frequency.Rahn teaches transmitting multiple subcarriers at respective frequencies, including “optical subcarriers SC1 to SC4 having frequencies f1 to f4.” (Rahn, col. 16, ll. 18–22).
Re: transmitting a plurality of second optical subcarriers at second frequencies within a spectral gap.Rahn teaches spectral gaps between subcarriers, including “associated frequency gaps G1-1 to G1-3.” (Rahn, col. 16, ll. 18–24).Rahn further teaches configurable frequency assignments/spacings (Rahn, col. 16, ll. 1–4) and also teaches generating a variable gap between subcarriers, i.e., “means for generating a variable frequency gap between a first subcarrier and a second subcarrier.” (Rahn, col. 31, ll. 20–24).Thus, it would have been obvious to allocate multiple (second) subcarriers to available spectral regions/gaps based on configurable spacing and gap control.
Re: changing the plurality of second frequencies.Zhou teaches adjusting/tuning carrier frequency, i.e., “the carrier frequency is tuned to the center of the channel.” (Zhou, p. 7).Accordingly, it would have been obvious to change (retune) the plurality of second frequencies to improved spectral locations (e.g., toward a desired center reference) based on feedback/performance criteria.
Re: adding a plurality of third optical subcarriers with third frequencies that begin within the spectral gap.Zhang teaches hitless spectrum retuning/defragmentation and explicitly teaches consolidating spectrum usage, including that defragmentation “aims at consolidating” spectrum usage and shows “consolidate the spectrum usage …” via defragmentation. (Zhang, p. 1).Zhang further explains that hop-tuning based retuning can enable full defragmentation (as contrasted with limitations of spectrum sweeping) and thereby creates larger contiguous available spectral regions suitable for additional allocations. (Zhang, p. 1).Thus, in view of Rahn’s multi-subcarrier transmitter with configurable gaps and frequency assignments (Rahn, col. 16, ll. 1–4; col. 16, ll. 18–24), it would have been obvious to add additional (third) subcarriers whose allocated frequencies begin within newly freed/contiguous spectral regions resulting from retuning/defragmentation as taught by Zhang, thereby increasing capacity and improving utilization.
One of ordinary skill in the art would have been motivated to combine Rahn, Zhou, and Zhang because Rahn provides a practical multi-subcarrier transmission structure with configurable spacing and gap control, Zhou teaches tuning carriers to desired center/channel locations to improve performance, and Zhang teaches spectrum retuning/defragmentation to consolidate spectrum usage and create contiguous available spectral regions for additional allocations, improving utilization and reducing blocking. Therefore, claim 2 would have been obvious.
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
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Mohammed Abdelraheem, whose telephone number is (571) 272-0656. The examiner can normally be reached Monday–Thursday.
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/MOHAMMED ABDELRAHEEM/Examiner, Art Unit 2635
/DAVID C PAYNE/Supervisory Patent Examiner, Art Unit 2635