Nokia Solutions and Networks OY

Patent Trials and Appeals Board

Aug 23, 2021

2020002541 (P.T.A.B. Aug. 23, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
15/885,385 01/31/2018 Vincent Houtsma 104182-US-NP 1068
46850 7590 08/23/2021
MENDELSOHN DUNLEAVY, P.C.
1500 JOHN F. KENNEDY BLVD., SUITE 910
PHILADELPHIA, PA 19102
EXAMINER
BELLO, AGUSTIN
ART UNIT PAPER NUMBER
2637
NOTIFICATION DATE DELIVERY MODE
08/23/2021 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
docketing@mendelip.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte VINCENT HOUTSMA and DOUTJE VAN VEEN
____________________

Appeal 2020-002541
Application 15/885,385
Technology Center 2600
____________________

Before ST. JOHN COURTENAY III, MARC S. HOFF, and
JOHN A. EVANS, Administrative Patent Judges.

EVANS, Administrative Patent Judge.

DECISION ON APPEAL1
Appellant2 seeks our review3 under 35 U.S.C. § 134(a) from the final
rejection of Claims 1–17, all pending claims. Appeal Br. 2. We have
jurisdiction under 35 U.S.C. § 6(b).

1 Our Decision refers to Appellant’s Appeal Brief filed August 19, 2019
(“Appeal Br.”); Appellant’s Reply Brief filed February 11, 2020 (“Reply
Br.”); Examiner’s Answer mailed December 12, 2019 (“Ans.”); the Final
Rejection mailed March 15, 2019 (“Final Act.”), and the Specification filed
January 31, 2018 (“Spec.”).
2 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. The Appeal Brief identifies Nokia Solutions and
Networks Oy, a Finnish corporation, as the real party in interest. Appeal
Br. 2.
3 We have considered in this decision only those arguments Appellant has
actually raised in the Briefs. Any other arguments which Appellant’s could
Appeal 2020-002541
Application 15/885,385

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We REVERSE.

STATEMENT OF THE CASE
INVENTION.
The claims relate to a passive optical network having an optical-signal
monitor configured to monitor carrier-wavelength drifts during optical bursts
transmitted between the optical line terminal and optical network units
thereof. See Abstract.
An understanding of the invention can be derived from a
reading of Claim 1, the sole independent claim which is reproduced
below with some formatting added:
1. An apparatus comprising an optical receiver, the optical
receiver having an optical burst monitor and being configured to
receive data-modulated optical signals from a plurality of optical
transmitters operable in optical burst mode; and
wherein the optical burst monitor comprises:
an optical mixer configured to generate an optical
output signal by optically mixing a first portion of an
optical burst and a second portion of the optical burst, the
second portion being delayed with respect to the first
portion;
a photodetector configured to convert the optical
output signal into a corresponding electrical signal; and
a signal processor configured to generate an
estimate of carrier-wavelength drift during the optical
burst based on a beat frequency of said corresponding
electrical signal.

have made but chose not to make in the Briefs are deemed to be forfeit. See
37 C.F.R. § 41.37(c)(1)(iv).
Appeal 2020-002541
Application 15/885,385

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REJECTIONS4 AT ISSUE
1. Claims 1, 2, 4, 6–9, and 12–15 stand rejected under 35 U.S.C. §
102 (a)(l) as anticipated by Effenberger (US 2008/0085118 Al; April
10, 2008). Final Act. 2–6.
2. Claims 3, 5, 10, 11, 16, and 17 stand rejected under 35 U.S.C. §
103 as Obvious over Effenberger (US 2008/0085118 Al; April 10,
2008). Final Act. 6–9.

ANALYSIS
We have reviewed the Examiner’s rejections in light of Appellant’s
arguments that the Examiner has erred. We find Appellant’s persuasive with
respect to the rejections under §§ 102 and 103.
CLAIMS 1, 2, 4, 6–9, AND 12–15: ANTICIPATION BY EFFENBERGER.
Appellant states: “claims 2, 4, 6-9, and 12-15 are novel over Effenberger, as
applied in the final Office Action, at least by their dependence from novel
claim 1.” Appeal Br. 6. In view of Appellant’s statement, we decide the
appeal of the § 102 rejections on the basis of Claim 1 and refer to the
rejected claims collectively herein as “the claims.” See 37 C.F.R. §
41.37(c)(1)(iv); In re King, 801 F.2d 1324, 1325 (Fed. Cir. 1986). See In re
McDaniel, 293 F.3d 1379, 1383 (Fed. Cir. 2002) (“[T]he Board is free to
select a single claim from each group of claims subject to a common ground
of rejection as representative of all claims in that group and to decide the

4 The present application, filed on or after March 16, 2013, is being
examined under the first inventor to file provisions of the AIA. Final Act. 2.
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Application 15/885,385

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appeal of that rejection based solely on the selected representative claim” in
the absence of a clear statement asserting separate patentability of the
claims.).
Claim 1, the sole independent claim, recites, inter alia, “a signal
processor configured to generate an estimate of carrier-wavelength
drift during the optical burst based on a beat frequency of said
corresponding electrical signal.” The Examiner finds Effenberger teaches:
a signal processor . . . configured to generate an estimate of
carrier-wavelength drift during the optical burst based on a beat
frequency of said corresponding electrical signal (e.g. “beat-
tone”).
Final Act. 3 (citing Effenberger, Fig. 2, numeral 259, 261; ¶ 28).
Appellant contends Effenberger converts received optical signals into
binary bits wherein if the optical signal is accompanied by an RF-beat tone,
the signal is converted into a digital “one,” and wherein the RF-beat tone is
absent, the signal is converted into a digital “zero.” Appeal Br. 4. Appellant
argues optical detection in Effenberger is performed in a manner that negates
carrier-wavelength drift:
Because this detection method compares the transmitted signal
to itself, it negates all of the common mode drift of the ONU
transmitter and isolates only the changes in the transmitter that
occur at the bit period. The residual drift in a signal bit period
is minimal or nonexistent because the bit period is relatively
short, e.g. one ns for a one gigabit per second (Gbps) signal.
Id. 4–5. Appellant argues: “Effenberger’s circuit 259, 261 appears to be
specifically designed and configured to be insensitive to the carrier-
wavelength drift by negating it and/or making its manifestations ‘minimal or
nonexistent.’” Appeal Br. 5. Appellant further argues: “being insensitive to
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Application 15/885,385

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the carrier-wavelength drift appears to be incompatible with and/or an
opposite of being able to sense the carrier-wavelength drift to generate an
estimate thereof as in present claim 1.” Id.
The Examiner finds Effenberger paragraph 28, as cited by the
Examiner and discussed by Appellant, discloses the processor “negates all of
the common mode drift of the ONU transmitter.” Ans. 3. The Examiner
finds that Appellant conflates common mode drift with the claimed carrier-
wave drift. Ans. 4.
The Examiner’s Answer is problematic because it was the Examiner
who cited the discussed paragraph as teaching carrier-wavelength drift.
Final Act. 3 (citing Effenberger, ¶ 28) (“a signal processor . . . configured to
generate an estimate of carrier-wavelength drift”). Moreover, contrary to the
Examiner’s finding, the “beat-tone” is not disclosed as being sensitive to a
wavelength drift, but is disclosed as being sensitive to the sum and
difference of a wavelength:
The balanced detector 259 may receive the two optical signals
from the two-by-two coupler 257 and produce RF tones using
the two signals. In some embodiments, the balanced detector
259 may have two elements, one element to detect the sum of
the received signal and the copied signal, and another element
to detect the difference between the received signal and the
copied signal. If the ONU 106A sent a ‘one’, then there is
interference between the received signal and the copied signal,
and a RF beat-tone is generated. If a ‘zero’ is sent from the
ONU 106A, then there is little or no interference between the
received signal and the copied signal, and only a minimal or no
RF tone is produced.
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Application 15/885,385

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Effenberger, ¶ 28. We find no disclosure in the prior art of “a signal
processor configured to generate an estimate of carrier-wavelength drift,” as
claimed.
Appellant contends that Effenberger does not teach an optical burst
monitor. Reply Br. 2. Appellant explains Effenberger discloses a
“Frequency Division Multiple Access Passive Optical Network” (“FDMA
PON”) and contrasts FDMA PONs against Time Division Multiple Access
(TDMA) PONs and/or Wavelength Division Multiple Access (WDMA)
PONs. Id. Appellant argues the person of ordinary skill in the optical-
communications arts would understand that the FDMA techniques, disclosed
by Effenberger, do not rely upon optical bursts and that Effenberger does not
disclose the term “burst.” Id.
Appellant discloses
The International Telecommunication Union’s
Telecommunication Standardization Sector (ITU-T) selected
the Time and Wavelength Division Multiplexing (TWDM)
PON concept for use in the Next Generation of PONs (e.g.,
NG-PON2). In a corresponding TWDM-PON system, at least
the uplink transmissions are carried out in a burst mode.
However, a relatively large carrier-wavelength drift of an ONU
laser operated in a burst mode can disadvantageously cause the
corresponding optical signal to drift out of its allotted spectral
band, thereby causing, e.g., power loss for the current
wavelength channel and severe interference for one or more
adjacent wavelength channels.
Spec. 2–3. Appellant further discloses: “a disclosed PON system can be
configured to operate such that the amounts of wavelength drift satisfy the
Maximum Spectral Excursion (MSE) requirement(s) specified in
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Application 15/885,385

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Recommendation ITU-T G.989.2 (12/2014), which is incorporated herein by
reference in its entirety.”5 Spec. 3.
Document G.989 discloses TWDM and WDM multiplexing
techniques, but fails to disclose FDMA techniques. See G.989, 8–10.
Document G.989 further defines burst mode transmission. See G989.
We find that Effenberger discloses FDMA techniques, but not the
claimed TWDM and WDM multiplexing techniques. Therefore, we find
Effenberger fails to disclose or teach “a signal processor configured to
generate an estimate of carrier-wavelength drift during the optical burst
based on a beat frequency of said corresponding electrical signal,” as
claimed. We, therefore, decline to sustain the Examiner’s rejection of
Claims 1, 2, 4, 6–9, and 12–15 as being anticipated by Effenberger.
CLAIMS 3, 5, 10, 11, 16, AND 17: OBVIOUSNESS OVER EFFENBERGER.
Claims 3, 5, 10, 11, 16, and 17 depend from independent Claim 1.
Because we find we find Effenberger fails to disclose or teach “a signal
processor configured to generate an estimate of carrier-wavelength drift
during the optical burst based on a beat frequency of said corresponding
electrical signal,” as claimed, We decline to sustain the rejection of Claims
3, 5, 10, 11, 16, and 17.

5 Hereinafter referred to as “G.989.”
Appeal 2020-002541
Application 15/885,385

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DECISION
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1, 2, 4, 6–
9, 12–15
102 (a)(l) Effenberger 1, 2, 4, 6–
9, 12–15
3, 5, 10,
11, 16, 17
103 Effenberger 3, 5, 10,
11, 16, 17
Overall
Outcome
1–17

REVERSED